Method for preparing a composite material having an elastomer and a filler.

Abstract

Disclosed herein is a method for preparing a composite material from at least a solid elastomer and a wet filler. In one or more mixing steps, the method includes mixing at least a solid elastomer and a wet filler to form a mixture, and removing at least a portion of the liquid from the mixture by evaporation. One or more rotors of the mixer are mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under power control, where the rotational speed of the one or more rotors is controlled by a controller that (i) calculates the difference between a measured mixer motor output and a power set point, and (ii) adjusts the rotational speed of the one or more rotors if the measured mixer motor output deviates from the power set point.

Description

[Technical Field]

[0001] A method for preparing a composite material by mixing at least a solid elastomer and a wetting filler, wherein a portion of the mixing is performed under power control, is disclosed herein. Also disclosed are composite materials produced by the method of the present invention and corresponding vulcanized products derived from these composite materials. [Background technology]

[0002] The development of methods for dispersing fillers in elastomers has always been desired in the rubber industry, and it is particularly desirable to develop methods that can do so efficiently in terms of filler dispersion quality, time, labor, and / or cost.

[0003] Many commercially important products are formed from elastomer compositions in which reinforcing fillers are dispersed in either various synthetic elastomers, natural rubber, or elastomer blends. For example, carbon black and silica are widely used to reinforce natural rubber and other elastomers. It is common to produce masterbatches, i.e., premixtures of various optional additives such as reinforcing fillers, elastomers, and extender oils. Such masterbatches are then compounded with processing and curing additives, and upon curing, produce many commercially important products.

[0004] Good dispersion of reinforcing fillers in rubber compounding is recognized as a factor in achieving mechanical strength and consistent performance of elastomer composites and rubber compounding. Significant effort has been made to develop methods for improving dispersion quality, and various solutions have been proposed to address this challenge. For example, more vigorous mixing can improve the dispersion of reinforcing fillers, but it can degrade the elastomer in which the fillers are dispersed. This is particularly problematic in the case of natural rubber, which is highly susceptible to mechanical / thermal degradation, especially under dry mixing conditions.

[0005] Therefore, it is necessary to develop methods for incorporating fillers into solid elastomers in order to achieve acceptable or improved elastomer composite dispersion quality and functionality from elastomer composite masterbatches, which can be converted into acceptable or improved properties in the corresponding vulcanized rubber compound and rubber articles. [Overview of the project]

[0006] One embodiment is a method for preparing a composite material, (a) A step of filling a mixer having one or more rotors with a wetting filler comprising at least a solid elastomer and a liquid that is present in an amount of at least 15% by weight based on the total weight of the filler and the wetting filler, (b) In one or more mixing steps, a step is made to mix at least a solid elastomer and a wetting filler to form a mixture, and to remove at least a portion of the liquid from the mixture by evaporation, and in at least one of the mixing steps, the mixing is performed in at least one of the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) The process is applicable in which one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, (c) Discharging from a mixer a composite material comprising a filler dispersed in an elastomer at a loading amount of at least 20 phr, wherein the composite material has a liquid content of 10% by weight or less based on the total weight of the composite material, The present invention provides a method in which one or more rotors are mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under output control controlled by a controller, which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint.

[0007] Another embodiment is a method for preparing a composite material, (a) A step of filling a first mixer having one or more rotors with a wetting filler comprising at least a solid elastomer and a liquid that is present in an amount of at least 15% by weight based on the total weight of the filler and the wetting filler, (b) In one or more mixing steps, a step is made to mix at least a solid elastomer and a wetting filler to form a mixture, and to remove at least a portion of the liquid from the mixture by evaporation, and in at least one of the mixing steps, the mixing is performed in at least one of the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) One or more rotors shall operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, One or more rotors are mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under output control controlled by a controller, where the rotational speed of one or more rotors is (i) calculated to be the difference between the measured mixer motor output and the output setpoint, and (ii) adjusted to be the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint. (c) A step of discharging a mixture from a first mixer at a loading amount of at least 20 phr, the mixture having a liquid content reduced to less than the liquid content at the start of step (b), The present invention provides a method comprising the step of mixing the mixture from (d)(c) in a second mixer to obtain a composite material.

[0008] Another embodiment is a method for preparing a composite material, (a) A step of filling a first mixer having one or more rotors with a wetting filler comprising at least a solid elastomer and a liquid that is present in an amount of at least 15% by weight based on the total weight of the filler and the wetting filler, (b) In one or more mixing steps, a step is made to mix at least a solid elastomer and a wetting filler to form a mixture, and to remove at least a portion of the liquid from the mixture by evaporation, and in at least one of the mixing steps, the mixing is performed in at least one of the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) The process is applicable in which one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, (c) A step of discharging a mixture from a first mixer at a loading amount of at least 20 phr, the mixture having a liquid content reduced to less than the liquid content at the start of step (b), (d) The step of mixing the mixture from (c) in a second mixer to obtain a composite material, The second mixer has one or more rotors mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is such that the rotational speed of one or more rotors is such that (i) the difference between the measured mixer motor output and the output setpoint is calculated, and (ii) the measured mixer motor The present invention provides a method that includes a process performed under output control controlled by a controller, which adjusts the rotational speed of one or more rotors when the output deviates from an output setpoint.

[0009] For any aspect or method or embodiment disclosed herein, where applicable, the method can further include any one or more of the following embodiments: at least a portion of the mixing in step (b) is performed under PID output control; the output setpoint expressed as a ratio output is in the range of 1 to 10 kW / kg; in the case of (i), the controller continuously calculates the difference between the measured mixer motor output and the output setpoint; the controller calculates the difference between the measured mixer motor output and the output setpoint at a set time interval in the range of 0.05 seconds to 5 seconds, for example, 0.05 seconds to 1 second; in the case of (ii), the controller continuously adjusts the rotational speed of one or more rotors when the measured mixer motor output deviates from the output setpoint; in the case of (ii), the controller continuously adjusts the rotational speed of one or more rotors when the measured mixer motor output deviates from the output setpoint; the controller automatically calculates the difference between the measured mixer motor output and the output setpoint and adjusts the rotational speed of one or more rotors when the measured mixer motor output deviates from the output setpoint.

[0010] For any aspect or method or embodiment disclosed herein, where applicable, the method can further include any one or more of the following embodiments: after filling the mixer with a solid elastomer and filling the mixer with a wet filler, the mixing is performed under output control. The method includes filling the mixer with at least two portions of the wet filler, and the mixing is performed under output control after filling the mixer with the first portion of the wet filler; the mixing is performed under output control after filling the mixer with each portion of the wet filler; the first portion of at least two portions of the wet filler is at least 50% by weight of the total amount of the wet filler filled in the mixer; the solid elastomer is kneaded before filling at least a portion of the wet filler into the mixer; the solid elastomer is not kneaded before filling at least a portion of the wet filler into the mixer.

[0011] For any aspect or method or embodiment disclosed herein, where applicable, the method can further include any one or more of the following embodiments. The wetting filler has a liquid present in an amount of at least 20% by weight, for example, in the range of 40% to 65% by weight, based on the total weight of the wetting filler; the filler includes at least one material selected from carbonaceous materials, carbon black, silica, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, pyrolytic carbon, graphene, graphene oxide, reduced graphene oxide, carbon nanotubes, single-walled carbon nanotubes, multi-walled carbon nanotubes, and combinations thereof, and coatings and treated materials thereof; the filler is selected from rice husk silica, lignin, nanocellulose, hydrothermal carbon, artificial polysaccharides, and combinations thereof, and coatings and treated materials thereof; the filler is selected from carbon nanostructures; the filler is selected from carbon black, silica, silicon-treated carbon black, and blends thereof; the filler is selected from carbon black, silicon-treated carbon black, and blends thereof; at least 50% of the filler is selected from carbon black, silicon-treated carbon black, and blends thereof; the solid elastomer is selected from natural rubber, functionalized natural rubber, styrene-butadiene rubber, functionalized styrene-butadiene rubber, polybutadiene rubber, functionalized polybutadiene rubber, polyisoprene rubber, ethylene-propylene rubber, isobutylene-based elastomers, polychloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polysulfide rubber, polyacrylate elastomers, fluoroelastomers, perfluoroelastomers, silicone elastomers, and blends thereof.

[0012] With respect to any aspect, method, or embodiment disclosed herein, where applicable, the method may further include any one or more of the following embodiments: one or more rotors selected from two-blade rotors, four-blade rotors, six-blade rotors, eight-blade rotors, and one or more screw rotors; one or more rotors selected from four-blade rotors, six-blade rotors, and eight-blade rotors; one or more rotors selected from cross-reverse rotors; the mixing time, defined as the filling time in (a) to the discharge time in (c), is in the range of 1 to 9 minutes, for example, 3 to 6 minutes.

[0013] With respect to any aspect, method or embodiment disclosed herein, where applicable, the Method may further include any one or more of the following embodiments: mixing is performed in two or more mixing steps; the mixer in (a) is a first mixer, and the Method further includes mixing at least a portion of the composite material from (c) in a second mixer; the mixer in (a) is a first mixer, and the Method further includes mixing at least a portion of the composite material from (c) in a second mixer, wherein the second mixer is provided for the following conditions: (i) ram pressure of 5 psi or less; (ii) ram rises to at least 75% of its highest level; (iii) ram operates in floating mode; (iv) (i) the ram is positioned so as not to come into substantial contact with the mixture; (v) the mixer is ramless; and (vi) the filling rate of the mixture is in the range of 25% to 70%; and (e) the composite material having a liquid content of less than 3% by weight based on the total weight of the composite material is discharged from a second mixer; the first and second mixers are identical; the first and second mixers are different mixers; the first and second mixers together are a tandem mixer; the second mixer is ramless; and in the case of mixing in (d), the second mixer operates under at least one of the following conditions (i) to (vi) for at least 50% of the mixing time.

[0014] With respect to any aspect, method or embodiment disclosed herein, where applicable, the method may further include any one or more of the following embodiments: (a) is a first mixer, and the method further includes mixing at least a portion of the composite material from (c) in a second mixer, the second mixer having one or more rotors mechanically coupled to a mixer motor, and at least a portion of the mixing in the second mixer is performed under power control controlled by a controller that (i) calculates the difference between a measured mixer motor output and a power setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the power setpoint; at least a portion of the power-controlled mixing in the second mixer is performed with the ram raised to at least 75% of its highest level; and the power-controlled mixing in the second mixer is performed after the addition of at least one additive. [Brief explanation of the drawing]

[0015] [Figure 1] The mixing curve for the first stage of the comparative example is shown.

[0016] [Figure 2] The mixing curve for the first stage of mixing in Example 1 is shown. [Modes for carrying out the invention]

[0017] International Publication No. 2020 / 247663(A1) (the disclosure thereof is incorporated herein by reference) describes a mixing process for a solid elastomer with a wet filler containing a filler and a liquid. When applied to a batch process, the presence of a liquid (e.g., water) increases the residence time compared to a dry mixing process, which can allow for improved filler dispersion without substantial decomposition of the elastomer. Under certain conditions, for example when scaling up, a considerable amount of liquid must be removed, thereby increasing the batch time. The batch time can be up to 2 to 5 times longer than that of a conventional dry mixing process.

[0018] Batch time can be reduced by maximizing the rotational speed of the mixer rotor, thereby maximizing the input output. Since the output input to the mixer is proportional to the amount of heat generated, increasing the output input increases the rate of water evaporation. However, the extent to which the rotational speed can be increased is limited by one or more of the following factors: Mixer rotor speed capability, and / or Excessive power peaks after component addition (if the rotation speed is too high after component addition, the resulting power peak may exceed the mixer's capacity), and / or Excessive steam generation (If the rotation speed is too high, the mixer may generate excessive steam for the mixer ventilation system, which can cause safety issues when the mixer rum subsequently rises to add further components).

[0019] Disclosed herein is a method for shortening the mixing time by controlling the rotor speed (rotor speed) through mixer output control for at least a portion of the mixing of a mixture formed from at least a wetting filler and a solid elastomer. The mixing time may be a single-stage or first-stage batch time. Accordingly, one embodiment disclosed herein is a method for preparing a composite material, (a) A step of filling a mixer having one or more rotors with a wetting filler comprising at least a solid elastomer and a liquid that is present in an amount of at least 15% by weight based on the total weight of the filler and the wetting filler, (b) In one or more mixing steps, a step is made to mix at least a solid elastomer and a wetting filler to form a mixture, and to remove at least a portion of the liquid from the mixture by evaporation, and in at least one of the mixing steps, the mixing is performed in at least one of the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) The process is applicable in which one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, (c) Discharging from a mixer a composite material comprising a filler dispersed in an elastomer at a loading amount of at least 20 phr, wherein the composite material has a liquid content of 10% by weight or less based on the total weight of the composite material, The method is characterized in that one or more rotors are mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under output control controlled by a controller that (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint.

[0020] A method for preparing a composite material includes the step of filling or introducing at least a solid elastomer and a wetting filler into a mixer. By combining the solid elastomer and the wetting filler, a mixture is formed during the mixing step. The method further includes performing the mixing such that in one or more mixing steps (e.g., one mixing step), at least a portion of the liquid is removed by evaporation or by an evaporation process that takes place during mixing. The liquid of the wetting filler can be removed by evaporation (at least a portion can be removed under the claimed mixing conditions), and can be a volatile liquid, for example, volatile at the bulk mixture temperature. For example, a volatile liquid can be distinguished from an oil (e.g., extender oil, process oil) that may be present for at least a portion of the mixing, and such an oil means that it is present in the composite material being released and therefore does not evaporate for most of the mixing time.

[0021] In the wetting filler of the present invention, a liquid or additional liquid can be added to the filler, and this liquid or additional liquid may be present on most or substantially all of the surface of the filler, and such surface may include an inner surface or pores that are accessible to the liquid. Thus, sufficient liquid is provided to wet most or substantially all of the surface of the filler before mixing with the solid elastomer. During mixing, at least a portion of the liquid may also be removed by evaporation when the wetting filler is dispersed in the solid elastomer, and the surface of the filler may then become available for interaction with the solid elastomer.

[0022] The liquid used to wet the filler may be, but is not limited to, an aqueous liquid such as water, or may contain such liquid. The liquid may contain at least one other component, for example, but is not limited to, a base, acid, salt, solvent, surfactant, and / or processing aid, and / or any combination thereof. The liquid may be, but may contain, a solvent (for example, an alcohol such as ethanol) that is immiscible with the elastomer used. Alternatively, the liquid may consist of about 80% to 100% by weight of water or 90% to 99% by weight of water based on the total weight of the liquid.

[0023] The filling of solid elastomers and / or wetting fillers can be carried out in one step or addition, or in multiple steps or additions. The filling of solid elastomers and wetting fillers can all be carried out at once or sequentially (as single or multiple parts), and in any order. One option is to fill the mixer with the wetting filler in two or more parts. Another option is to fill the mixer with the wetting filler after at least a portion or substantially all (e.g., at least 90%) of the solid elastomer has been filled. For example, filling may include filling the mixer with substantially all or all of the solid elastomer, followed by filling the mixer with two or more portions of the wetting filler. The first portion of the wetting filler optionally corresponds to at least 50% by weight of the total amount of wetting filler to be filled into the mixer, e.g., at least 60% by weight, at least 70% by weight, at least 75% by weight, at least 80% by weight, or at least 90% by weight. Alternatively, the first portion of the wetting filler may optionally correspond to 50–95% by weight (e.g., 60–95% by weight, 70–95% by weight, 80–95% by weight, 90–95% by weight, or 90–99% by weight) of the total amount of wetting filler to be filled into the mixer. The filling of the solid elastomer or wetting filler may be carried out in any manner, including but not limited to conveying, weighing, loading, and / or supplying, as known in the art.

[0024] Regarding mixing, mixing can be carried out in one or more mixing steps. Mixing begins when at least the solid elastomer and wetting filler are filled into the mixer and energy is applied to the motors that drive one or more rotors of the mixer. One or more mixing steps may be performed after the filling step is completed or may overlap with the filling step for any length of time. For example, one or more portions of the solid elastomer and / or wetting filler may be filled into the mixer before or after mixing has started. Then, one or more additional portions of the wetting filler and / or solid elastomer may be filled into the mixer. In the case of batch mixing, the filling step is completed before the mixing step is completed.

[0025] When mixing a wetting filler with a solid elastomer, specific mixing conditions can be applied. For example, a mixer may have temperature control means for controlling the temperature of at least one surface of the mixer. Optionally, the mixer temperature can be controlled during both the filling process and at least one mixing process. The temperature control means may be a temperature control device on and / or within the mixer, or attached to the mixer (e.g., connected to the mixer), which heats or cools at least one surface and / or one or more parts of the mixer. The temperature control means may, but are not limited to, a flow or circulation of a heat transfer fluid through channels in one or more parts of the mixer. For example, the heat transfer fluid may be water or heat transfer oil. For example, the heat transfer fluid may flow through a rotor, mixing chamber wall, ram, and drop door. In other embodiments, the heat transfer fluid may flow within a jacket (e.g., a jacket with fluid flow means) or coils around one or more parts of the mixer. Alternatively, the temperature control means (e.g., supplying heat) may be an electrical element embedded in the mixer. The system providing the temperature control means may further include means for measuring either the temperature of the heat transfer fluid or the temperature of one or more parts of the mixer. The temperature measurements can be supplied to a system used to control the heating and cooling of the heat transfer fluid. For example, a desired temperature of at least one surface of the mixer can be controlled by setting the temperature of the heat transfer fluid located in channels adjacent to one or more parts of the mixer, such as walls, doors, rotors, etc.

[0026] The temperature of at least one temperature control means can be set and maintained by, for example, one or more temperature control units ("TCU"). This set temperature or TCU temperature is referred to herein as "T z It is also called "heat transfer fluid." In the case of a temperature control means that incorporates a heat transfer fluid, T z This is an indicator of the temperature of the fluid itself.

[0027] As an option, the temperature control means can be set to a temperature Tz of at least 65°C, for example, at least 70°C, at least 80°C, at least 90°C, or 65°C to 140°C, or within the range of 65°C to 130°C, 65°C to 120°C, 65°C to 110°C, 65°C to 100°C, 65°C to 95°C, 70°C to 140°C, 70°C to 130°C, 70°C to 120°C, 70°C to 110°C, 70°C to 100°C, 80°C to 140°C, 80°C to 130°C, 80°C to 120°C, 80°C to 110°C, 80°C to 100°C, or any other temperature within approximately these ranges.

[0028] Temperature control means and T z Further features are described in International Publication No. 2020 / 247663(A1), which is incorporated herein by reference.

[0029] As an option, the process includes performing mixing such that in at least one of the mixing steps, one or more rotors operate at a tip speed of at least 0.5 m / s for at least 50% of the mixing time, or at a tip speed of at least 0.6 m / s for at least 50% of the mixing time. The output input to the mixer motor is at least partially a function of the speed of at least one rotor and rotor type. The tip speed, taking into account the rotor diameter and rotor speed, can be calculated according to the following formula. Tip speed, m / s = π × (rotor diameter, m) × (rotational speed, rpm) / 60

[0030] Since the tip velocity can vary throughout the mixing process, optionally, a tip velocity of at least 0.5 m / s or at least 0.6 m / s can be obtained over at least 50% of the mixing time, e.g., at least 60%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or substantially the entirety of the mixing time. The tip velocity may be at least 0.6 m / s, at least 0.7 m / s, at least 0.8 m / s, at least 0.9 m / s, at least 1.0 m / s, at least 1.1 m / s, at least 1.2 m / s, at least 1.5 m / s, or at least 2 m / s over at least 50% of the mixing time or the other parts of the mixing listed above. The tip velocity may be selected to minimize the mixing time, or it may be 0.6 m / s to 10 m / s, 0.6 m / s to 8 m / s, 0.6 to 6 m / s, 0.6 m / s to 4 m / s, 0.6 m / s to 3 m / s, 0.6 m / s to 2 m / s, 0.7 m / s to 4 m / s, 0.7 m / s to 3 m / s, 0.7 m / s to 2 m / s, 0.7 m / s to 10 m / s, 0.7 m / s to 8 m / s, 0.7 to 6 m / s, 1 m / s to 10 m / s, 1 m / s to 8 m / s, 1 m / s to 6 m / s, 1 m / s to 4 m / s, 1 m / s to 3 m / s, or 1 m / s to 2 m / s (for example, over at least 50% of the mixing time or other mixing times as specified herein). Alternatively or additionally, the tip velocity can be selected to maximize throughput. The time / throughput ratio can take into account that as the mixing time decreases, the liquid level in the released composite material may increase. In certain situations, it may be beneficial to perform mixing at a higher tip velocity for higher throughput balanced with the desired liquid content of the released composite material (for example, an excessively fast tip velocity may result in shorter residence or mixing times, failing to allow for sufficient filler dispersion or sufficient removal of liquid from the composite material).

[0031] Additional features for controlling tip speed are described in International Publication No. 2020 / 247663(A1), which is incorporated herein by reference.

[0032] During mixing, it is common to set the rotational speed (rpm) to a fixed value. However, while the rotational speed is fixed, the output used by the mixer can be variable. For example, an output peak may occur during the addition of one or more components, such as certain additional fillers and certain elastomers. In other cases, an output reduction may occur with the addition of other components, such as additives like degradation inhibitors. One embodiment provides a mixing method that addresses the variable output problem.

[0033] The mixer may be a batch mixer, for example, a closed mixer having a sealed mixing chamber. Examples of closed mixers include tangential mixers and cross-reverse mixers. The chamber capacity of the mixer may be at least 1 L, at least 10 L, at least 20 L, at least 30 L, at least 50 L, at least 100 L, or at least 1000 L, for example, 1 L to 1500 L, 10 L to 1500 L, 20 L to 1500 L, 30 L to 1500 L, 10 L to 1000 L, 20 L to 1000 L, 30 L to 1000 L, 10 L to 100 L, 20 L to 100 L, or 30 L to 100 L. Mixing is performed using at least one rotor located in the chamber and mechanically coupled to a motor. For example, at least one rotor or more rotors may be screw rotors, cross-reversing rotors, tangential rotors, kneading rotors, and rotors used in extruders. Generally, one or more rotors are utilized within a mixer, and for example, a mixer can incorporate one rotor (e.g., a screw rotor), two, four, six, eight, or more rotors. The set of rotors can be arranged in parallel and / or sequential orientations within a given mixer configuration. As one option, at least one rotor can be selected from a two-blade rotor, a four-blade rotor, a six-blade rotor, an eight-blade rotor, or other rotors known in the art (e.g., a cross-reversing rotor). As another option, at least one rotor can be selected from a four-blade rotor, a six-blade rotor, or an eight-blade rotor.

[0034] One embodiment provides a controller configured to control the rotational speed of a rotor. The controller may be software provided in an industrial control system (such as a programmable logic controller, PLC), or it may be a standalone controller. As an option, the controller is a proportional-integral-derivative (PID) controller in that it performs proportional-integral-derivative control of the rotational speed of the mixer's rotor. As an option, mixing can be performed under proportional and integral control without using differentiation (or with the differentiation set to 0).

[0035] The controller (i) calculates the difference between the measured mixer motor output and the output setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint. The controller (having a control loop) is configured to relay signals to a motor-driving system (a motor drive system driving one or more motors), the signals indicating the rotor speed. The motors are mechanically coupled to one or more rotors, and the motors may be powered electrically or hydraulically. The motors may be coupled to gearboxes coupled to the rotors. Sensors may be located on the power supply to the motor (to measure the power consumed), or may be positioned on the shaft, or otherwise mounted or coupled, to measure rotational speed and force so that the output generated by the motor can be calculated. Other mechanical couplings known in the art may also be used.

[0036] Output control (e.g., PID output control) or an output control loop may include measuring the mixer motor output to obtain the measured motor output, for example, the controller receiving an output consumption signal from the motor, which represents the output level generated by the motor. An output setpoint for the motor is predefined (targeted) and serves to constrain the output within the setpoint. As one option, the output setting point (expressed as relative output) is in the range of 1-10kW / kg, for example, 1-9kW / kg, 1-8.5kW / kg, 1-8kW / kg, 1-7kW / kg, 1-6kW / kg, 1-5kW / kg, 1-4kW / kg, 2-10kW / kg, 2-9kW / kg, 2-8.5kW / kg, 2-8kW / kg, 2-7kW / kg, 3-10kW / kg, 3-9kW / kg, 3-8.5kW / kg, 3-8kW / kg, 3-7kW / kg, 4-10kW / kg, for example, 4-9kW / kg, 4-8.5kW / kg, 4-8kW / kg, 4-7kW / kg, 5-10kW / kg, 5-9kW / kg, 5-8.5kW / kg, 5-8kW / kg, 5-7kW / kg, or 4.3-8.5kW / kg. As one option, the output setpoint, expressed as the specific power output of the first-stage or single-stage mixture, is in the range of 1 to 10 kW / kg, and other ranges in between, as disclosed herein. As another option, the output setpoint, expressed as the specific power output of the first-stage or single-stage mixture, is in the range of 4 to 10 kW / kg, and other ranges in between, as disclosed herein. The controller (e.g., a PID controller) can be configured to calculate the difference between the measured motor output and the output setpoint by determining the input signal, for example, based on the difference between the output consumption signal and the output setpoint. Using this difference, if the measured mixer motor output deviates from the output setpoint, the rotational speed (rpm) of one or more rotors is calculated and adjusted (or a correction is applied to the rotational speed).

[0037] Typically, the controller continuously calculates the difference between the measured motor output and the output setpoint. "Continuously" means that the calculation is performed repeatedly at set time intervals. The set time interval can be in the range of a few seconds or fractions of a second (e.g., every 5 seconds, every 4 seconds, every 3 seconds, every 2 seconds, every 1 second, every 0.5 seconds, every 0.2 seconds, every 0.1 seconds, 0.05 seconds, or other intervals known in the art), and may range, for example, from 0.05 seconds to 5 seconds, 0.05 seconds to 4 seconds, 0.05 seconds to 3 seconds, 0.05 seconds to 2 seconds, 0.05 seconds to 1 second, 0.05 seconds to 0.75 seconds, 0.05 seconds to 0.5 seconds, 0.05 seconds to 0.4 seconds, 0.05 seconds to 0.3 seconds, 0.05 seconds to 0.2 seconds, or 0.05 seconds to 0.1 seconds. Therefore, the difference between the measured motor output and the output setpoint is continuously calculated, and the controller adjusts the rotational speed if the measured output deviates from the output setpoint. In many cases, the measured output almost always deviates from the output setpoint, and the controller continuously adjusts the rotational speed. As an option, the controller process is automated. The controller automatically measures the motor output, calculates the difference between the measured motor output and the output setpoint, and adjusts and controls the rotor rotational speed (rpm).

[0038] Mixing under output control (e.g., PID output control) can reduce mixing time (batch time) because the controller calculates the difference between the measured output and the output setpoint and (if necessary) adjusts the rotation speed within a predetermined output constraint, i.e., the output setpoint. For example, in rubber mixing, there is usually a large output peak after the addition of filler and as the filler is incorporated into the elastomer. In this situation, the output control loop (e.g., PID output control loop) slows down the rotation speed to avoid excessive output usage. If the output exceeds the output setpoint, the controller detects this difference and adjusts the rotor rotation speed (in this case, by decreasing it). As the incorporation of the filler progresses, the output usage generally decreases (the output consumption signal from the motor decreases). If the output drops below the output setpoint, the output control loop (automatically) adjusts the rotation speed (in this case, by increasing it) to achieve the output setpoint. By eliminating the high and low extremes of output usage (output consumption signal) and increasing the rotational speed where possible, batch time can be minimized while avoiding safety issues associated with excessive output usage.

[0039] As an option, at least 10% of the mixing (mixing time or batch time) in (b) can be performed under power control, for example, at least 20%, at least 25%, at least 30%, at least 35%, at least 40%, at least 50% of the mixing, for example, 25% to 100%, 25% to 75%, or 25% to 50% of the mixing can be performed under power control. If one or more parts of the mixing can be performed under power control, the power setpoints for each of those parts may be the same or different. For example, the mixing can be performed under power control after each component (e.g., one or more parts of the wetting filler and / or one or more parts of the elastomer and / or one or more parts of at least one additive described herein) has been added to the mixing (filled).

[0040] The filling of solid elastomers and wetting fillers can be done all at once or sequentially, in any order. One or more portions of solid elastomers and wetting fillers can be filled into the mixer. For example, (a) all solid elastomers are added first, followed by all wetting fillers; (b) all wetting fillers are added first, followed by all solid elastomers; (c) all solid elastomers are added first, followed by a portion of the wetting fillers, followed by one or more remaining portions of the wetting fillers; (d) a portion of the solid elastomers is added first, followed by a portion of the wetting fillers, followed by the remaining portions of the solid elastomers and wetting fillers being added simultaneously or sequentially in any order; (e) a portion of the wetting fillers is added first, followed by a portion of the solid elastomers, followed by the remaining portions of the solid elastomers and wetting fillers being added simultaneously or sequentially in any order; or (f) a portion of the solid elastomers and a portion of the wetting fillers are added to the mixer as separate fillers simultaneously or nearly simultaneously, followed by the remaining portions of the solid elastomers and wetting fillers being added simultaneously or sequentially in any order. Steps (a) to (f) may also include the step of filling the mixer with at least one additive. Mixing can be performed under power control under any scenario in which at least a portion of the wetting filler and at least a portion of the solid elastomer are filled in the mixer.

[0041] As an option for the filling process, the solid elastomer may be filled into the mixer before filling with at least a portion of the wet filler, and the solid elastomer may be kneaded until it reaches a predetermined temperature, for example, about 90°C or 100°C or higher, before filling with the wet filler into the mixer. This temperature may be 90°C to 180°C, 100°C to 180°C, 110°C to 170°C, 120°C to 160°C, or 130°C to 160°C. The elastomer may be kneaded using the same or different mixers, for example, a closed mixer such as a Banbury mixer or Bravender mixer, an extruder, a roll mill, a continuous compounder, or other rubber mixing equipment. As another option, the solid elastomer to be filled into the mixer is not kneaded before filling with at least a portion of the wet filler into the mixer.

[0042] As an option, mixing is performed under power control after the mixer has been filled with the wetting filler, or after each filling of the wetting filler if multiple parts of the wetting filler are used. In a specific example, at least a portion of the solid elastomer may be filled into the mixer first, followed by the filling of one or more portions of the wetting filler. Mixing can then be performed under power control after the addition or filling of the wet filler. Additional portions of the solid elastomer may be filled into the mixer after at least a portion of the wetting filler has been filled into the mixer.

[0043] As another example, at least a portion of the wetting filler is initially loaded into the mixer, followed by the loading of at least one elastomer. Alternatively, when at least a portion of the wetting filler is initially loaded into the mixer, substantially all mixing is performed under power control. The wetting filler can be prepared before loading into the mixer, or it can be prepared in situ within the mixer, for example, by loading the mixer with dry filler and liquid. One or more portions (e.g., at least two portions) of the wetting filler can be loaded into the mixer, and mixing can be performed under power control after any or all portions of the wetting filler have been loaded into the mixer. Alternatively, mixing can be performed under power control after each portion of the wetting filler has been loaded into the mixer. Alternatively, the first portion of the wetting filler loaded into the mixer is at least 50% by weight of the total amount of wetting filler loaded into the mixer, or any other amount disclosed herein. Alternatively, the mixer may be filled with at least a solid elastomer and at least one additive, such as at least one degradation inhibitor, and then mixed under power control. Power control can be initiated either immediately after filling the mixer with the wetting filler (or a portion of the wetting filler) or after the mixture has been mixed for a certain period of time to ensure that the pressure inside the mixer is low enough to (substantially) lower the ram.

[0044] The use of power control (e.g., PID power control) in mixing can provide an additional layer of protection against excessive / insufficient power use. For example, limits can be set on the controller output, and the maximum and / or minimum rotational speed can be set, for example, by predefining the maximum and minimum power (rpm) limits of the control loop. The maximum limit can be set to the mixer's maximum rpm capacity, or to a lower value. Power setpoints can be selected by considering any number of factors. As an example, setpoints can be selected to avoid excessive power use that may result from component addition and / or vapor generation at any point in the mixing process. Setpoints can also be selected, for example, to maximize the rotor's rotational speed capacity when power peaks are not expected. As an example, faster rotational speeds can be applied to help increase the evaporation rate of the liquid introduced into the mixer from the wetting packing material.

[0045] The use of such higher rotational speeds may be inherent to mixing with wet fillers, as it may be necessary to rapidly evaporate and / or otherwise remove water from the system. This is in contrast to typical dry mixing processes, where shorter batch times are required, and increasing batch times to improve filler dispersion in the elastomer without substantially degrading the elastomer presents challenges.

[0046] In any embodiment disclosed herein, the controller may have a control loop configured to drive a motor. An initial control signal is relayed to the control loop, thereby causing the motor to rotate a rotor. An output consumption signal is received from the motor, which represents the output level generated by the motor. The method may further include determining an input signal based on the difference between the measured motor output (output consumption signal) and the motor's output setpoint. The input signal is then relayed to the control loop, thereby allowing the controller to correct or adjust the rotation of the rotor (via the control loop).

[0047] It is not uncommon for the input signal to an output control loop (e.g., a PID output control loop) (based on the difference between the measured motor output and the output setpoint) to be variable due to process variations and / or other random fluctuations, which in certain cases can make it difficult to achieve stable control (e.g., of the output). One option is to apply signal processing to the input signal to reduce the variation. One class of signal processing involves filters. A filter can be applied before relaying the input signal to calculate the difference between the measured motor output and the output setpoint. Filters are well known in the art, and an example of such a filter is the Kalman filter. The input signal has a signal-to-noise ratio. Using a filter, a controller can be configured to filter the input signal to produce a filtered input signal with an increased signal-to-noise ratio compared to the input signal. In parallel, the controller can be configured to generate a control signal (via the output control loop) based on the filtered input signal.

[0048] One or a combination of commercially available mixers having one or more rotors, temperature control means, and other components, and related mixing methods for producing rubber compounds, such as those disclosed in International Publication No. 2020 / 247663(A1), may be used in this method, the disclosure of which is incorporated herein by reference.

[0049] "One or more mixing steps" means that the steps disclosed herein may be a first mixing step and a subsequent further mixing step before release. Alternatively, one or more mixing steps may be a single mixing step, e.g., a one-stage or single-stage mixing step or process, and the mixing is performed under one or more of the following conditions: at least one of the mixer temperatures is controlled by a temperature control means having one or more rotors operating at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, and / or at least one of the temperature control means is controlled at a temperature of 65°C or higher. zIt is set to the following. In certain cases, in a single step or single mixing step, the composite material can be released with a liquid content of 10% by weight or less. In other embodiments, there are two or more mixing steps or mixing steps, one of which is the T described. z Alternatively, it may be performed as long as it is carried out under one or more of the leading-velocity conditions.

[0050] As shown, during one or more mixing steps, in any of the methods disclosed herein, at least some of the liquid and / or the wetting filler introduced into the mixture is at least partially removed by evaporation. Alternatively, one or more mixing steps or stages may further remove a portion of the liquid from the mixture by squeezing, compression, discharge, and / or squeezing, or any combination thereof. Or, a portion of the liquid may be discharged from the mixer after or while the composite material is being discharged.

[0051] As one option, the composite material is prepared as a single-step (single mixing step) process. As another option, the composite material is prepared in two (or more) mixing steps, which can be considered a multi-step or multi-stage mixing having a first mixing step or step and at least a second mixing step or step. One or more multi-stage mixing processes can be batch, continuous, semi-continuous, or a combination thereof, insofar as the step (e.g., the first step) which includes mixing a wetting filler with a solid elastomer is a batch mixing process in which the rotational speed of one or more rotors is automatically controlled by a controller over at least a portion of the mixing, as disclosed herein. In certain cases, two mixing steps can improve efficiency. In the first step, a primary mixing and filler dispersion process is carried out. The second mixing step is performed to further dry the composite material under conditions that avoid substantial overheating.

[0052] In the case of multi-stage mixing, the first step includes mixing a wet filler with a solid elastomer (e.g., the first step). The method then includes mixing or further mixing the mixture in at least a second mixing step or stage, using the same mixer (i.e., the first mixer) and / or using a second mixer different from the first mixer. Mixer and process combinations can be used in any of the methods disclosed herein, and mixers can be used sequentially, in parallel, and / or in conjunction with other processing equipment. For example, the first mixer may be a tangential mixer or a cross-reversing mixer, and the second mixer may be a tangential mixer, a cross-reversing mixer, an extruder, a kneader, or a roll mill. For example, the first mixer may be a first tangential mixer, and the second mixer may be a second (different) tangential mixer. Alternatively, the first and second mixers may be the same, with the composite material being discharged from the first mixer and then at least a portion of the composite material being loaded into the same mixer (the second mixer). Two or more mixing steps (stages) can be carried out using two or more mixers. Alternatively, the first and second mixers may together form a tandem mixer. In a tandem mixer, typically, the second mixing stage (second mixing step) is carried out using a ramless mixer. The multi-stage mixing (two or more mixing steps) according to this method is carried out to evaporate the liquid and disperse the filler.

[0053] Another embodiment is a method for preparing a composite material, (a) A step of filling a first mixer having one or more rotors with a wetting filler comprising at least a solid elastomer and a liquid that is present in an amount of at least 15% by weight based on the total weight of the filler and the wetting filler, (b) In one or more mixing steps, a step is made to mix at least a solid elastomer and a wetting filler to form a mixture, and to remove at least a portion of the liquid from the mixture by evaporation, and in at least one of the mixing steps, the mixing is performed in at least one of the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) One or more rotors shall operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, One or more rotors are mechanically coupled to a mixer motor, and for at least a portion of the mixing in step (b), the rotational speed of one or more rotors is controlled by a controller by calculating the difference between the measured mixer motor output and the output setpoint, and the controller adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint, (c) A step of discharging a mixture from a first mixer at a loading amount of at least 20 phr, the mixture having a liquid content reduced to less than the liquid content at the start of step (b), The present invention provides a method comprising the step of mixing the mixture from (d)(c) in a second mixer to obtain a composite material.

[0054] Controlling the mixing time in the first mixer (or first stage mixing) can allow for some dispersion of the filler into the elastomer, and then mixing in the second mixer (or second stage mixing) under conditions that minimize substantial or any degradation of the solid elastomer, such as natural rubber or a blend containing natural rubber. Thus, one or more steps of mixing in the first mixer involve the evaporation of at least some of the liquid so that the mixture discharged from the first mixer has a liquid content reduced to less than the liquid content at the start of step (b), for example, the liquid present in the wet filler. The liquid content can be reduced to 50% by weight, 60% by weight, 70% by weight, or more. The liquid content remaining in the discharged mixer may vary depending on the type of filler, the type of elastomer, the amount of filler loaded, etc. In certain embodiments, it may be desirable to have a specific amount of moisture remaining in the mixture in the mixing performed in the second mixer in order to take advantage of the wet mixing process and its benefits. Alternatively, with other fillers and / or elastomer types, it may be desirable to remove most of the liquid during one or more mixing steps in the first mixer. Thus, the released mixture may have a liquid content ranging from 0.5% to 20% by weight relative to the weight of the mixture (partially depending on the liquid content of the wetting filler), or other amounts as disclosed in International Publication 2020 / 247663(A1), the disclosure of which is incorporated herein by reference.

[0055] Mixing by the second mixer is performed under at least one of the following conditions: (i) ram pressure of 5 psi or less; (ii) ram is raised to at least 75% of the ram's highest level (e.g., at least 85%, at least 90%, at least 95%, or at least 99% or 100%); (iii) ram operates in floating mode; (iv) ram is positioned so as not to substantially contact the mixture; (v) is a ramless mixer; and (vi) the packing density of the mixture (at least solid elastomer and wetting filler) is in the range of 25% to 70%. As an alternative, the second mixer can operate with packing density of the mixture in the range of 25% to 70%, 25% to 60%, 25% to 50%, or 30% to 50%, based on dry weight. As an option, mixing by the second mixer can be performed under any of the following conditions for the mixing time: 0% to 100%, for example, 10% to 100%, 20% to 100%, 30% to 100%, 40% to 100%, 50% to 100%, 60% to 100%, 70% to 100%, 80% to 100%, or 90% to 100%.

[0056] Mixing in the second mixer can be performed without output control, or at least a portion of the mixing can be performed under output control. For example, the second mixer is a batch mixer having one or more rotors mechanically coupled to a mixer motor, and at least a portion of the mixing in the second mixer is performed under output control controlled by a controller that (i) calculates the difference between the measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint.

[0057] As an option, the power setting point (expressed as specific power) for the second stage of mixing is in the range of 1 to 10 kW / kg, for example, 1 to 9 kW / kg, 1 to 8.5 kW / kg, 1 to 8 kW / kg, 1 to 7 kW / kg, 1 to 6 kW / kg, 1 to 5 kW / kg, 1 to 4 kW / kg, 1.5 to 10 kW / kg, 1.5 to 9 kW / kg, 1.5 to 8.5 kW / kg, 1.5 to 8 kW / kg, 1.5 to 7 kW / kg, 1.5 to 6 kW / kg, 1.5 to 5 kW / kg, 1.5 to 4 kW / kg, 2 to 10 kW / kg, 2 to 9 kW / kg, 2 to 8.5 kW / kg, 2 to 8 kW / kg, 2 to 7 kW / kg, 2 to 6 kW / kg, 2 to 5 kW / kg, 2 to 4 kW / kg, or any other range disclosed herein, for example, the same range as the first stage of mixing. As one option, the power setpoint, expressed as the specific power of the first-stage or single-stage mixture, is in the range of 1 to 10 kW / kg, and other ranges in between as disclosed herein. As another option, the power setpoint, expressed as the specific power of the first-stage or single-stage mixture, is in the range of 4 to 10 kW / kg, and other ranges in between as disclosed herein.

[0058] As an option, at least a portion of the power-controlled mixing in the second mixer is performed with the ram raised to at least 75% of its maximum level. As an option, at least a portion of the power-controlled mixing in the second mixer is performed using a ramless mixer. As yet another option, the power-controlled mixing in the second mixer can be performed with the ram down. The method then includes releasing the formed composite material from the last used mixer such that the composite material has a liquid content of 10% by weight or less (or 5% by weight or less, 3% by weight or less, 2% by weight or less, or 1% by weight or less, or other amounts disclosed herein) based on the total weight of the composite material. Typically, a second mixing stage is performed to further dry the composite material. In any of the multi-stage processes disclosed herein, the final released composite material (e.g., the composite material released after a second or third or subsequent mixing step) may have a liquid content of 5% or less. While not bound by any particular theory, the use of output PID control in the second stage can allow for greater control over the drying rate during the final stage of drying. For example, such control can enable the masterbatch to dry without exceeding the target probe temperature range, thus preventing, for instance, the composite material from drying excessively rapidly.

[0059] As an alternative, multi-stage mixing includes a first stage of mixing not performed under power control, and at least one subsequent stage of mixing (e.g., a second stage of mixing) in which at least a portion of the mixing is performed under power control. Thus, another embodiment is a method for preparing a composite material, (a) A step of filling a first mixer having one or more rotors with a wetting filler comprising at least a solid elastomer and a liquid that is present in an amount of at least 15% by weight based on the total weight of the filler and the wetting filler, (b) In one or more mixing steps, a step is made to mix at least a solid elastomer and a wetting filler to form a mixture, and to remove at least a portion of the liquid from the mixture by evaporation, and in at least one of the mixing steps, the mixing is performed in at least one of the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) The process is applicable in which one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time, (c) A step of discharging a mixture from a first mixer at a loading amount of at least 20 phr, the mixture having a liquid content reduced to less than the liquid content at the start of step (b), (d) The step of mixing the mixture from (c) in a second mixer to obtain a composite material, The present invention provides a method comprising a step (b) in which the mixing is performed under power control controlled by a controller, the rotational speed of one or more rotors being (i) calculated by calculating the difference between a measured mixer motor power and a power setpoint, and (ii) adjusting the rotational speed of one or more rotors if the measured mixer motor power deviates from the power setpoint.

[0060] Further characteristics of the mixing, whether single-step or multi-step, are described in International Publication No. 2020 / 247663(A1), which is incorporated herein by reference.

[0061] In any method disclosed herein, a discharging step is performed from the mixer to obtain a composite material containing a filler dispersed in natural rubber at a total load of at least 20 phr, for example, 20 to 250 phr, or other loads disclosed herein. Substantially all of the filler loaded into the mixer is incorporated into the discharging composite material (the yield loss of the filler is 10% or less, 5% or less, 3% or less, 2% or less, or 1% or less).

[0062] The mixing time can be determined by the total mixing time or batch time, from the filling time (e.g., the time for filling the first component or the start of filling) to the release time of the composite material. In the case of a batch-closed mixer, the mixing time can be determined by the ram-down time as an alternative parameter, for example, the time the mixer operates with the ram in its lowest position, e.g., fully seated position, or with the ram deflected (as described in International Publication 2020 / 247663(A1) whose disclosure is incorporated herein by reference). The methods of this disclosure (e.g., for single-stage mixing or first-stage mixing) can result in a reduction of mixing time, whether total mixing time or ram-down time, by, for example, at least 5% or at least 10% compared to a mixing process performed without power control. The mixing time may be less than 10 minutes, less than 9 minutes, less than 8 minutes, less than 7 minutes, less than 6 minutes, or 1 to 10 minutes, for example, 1 to 9 minutes, 1 to 8 minutes, 3 to 10 minutes, 3 to 9 minutes, 3 to 8 minutes, 3 to 7 minutes, 3 to 6 minutes, 5 to 10 minutes, 5 to 9 minutes, 5 to 8 minutes, or 5 to 7 minutes. The ram-down time may be less than the total mixing time and may be less than 9 minutes, less than 8 minutes, less than 7 minutes, less than 6 minutes, or 1 to 9 minutes, 1 to 8 minutes, 3 to 9 minutes, 3 to 8 minutes, 3 to 7 minutes, 3 to 6 minutes, 3 to 5 minutes, 5 to 9 minutes, 5 to 8 minutes, or 5 to 7 minutes.

[0063] The method further includes discharging the formed composite material from the mixer. The discharged composite material may have a liquid content of 10% by weight or less based on the total weight of the composite material, as outlined in the following formula. Liquid content of composite material (%) = 100 * [Mass of liquid] / [Mass of liquid + Mass of dry composite material]

[0064] In any of the methods disclosed herein, the discharged composite material may have a liquid content of 10% by weight or less, for example, 9% by weight or less, 8% by weight or less, 7% by weight or less, 6% by weight or less, 5% by weight or less, 3% by weight or less, 2% by weight or less, or 1% by weight or less, based on the total weight of the composite material. This amount may range from 0.1% to 10% by weight, 0.5% to 9% by weight, 0.5% to 7% by weight, 0.5% to 5% by weight, 0.5% to 3% by weight, or 0.5% to 2% by weight, based on the total weight of the composite material discharged from the mixer at the end of the process. Alternatively, if two or more mixing stages are used, the liquid content discharged from the first mixing stage (where at least a solid elastomer and a wetting filler are filled into the mixer) may be greater than 10% by weight (e.g., less than 20% by weight), and the second or subsequent stage brings about further drying so that the composite material has a liquid content of 10% by weight or less, as disclosed herein. In any of the methods disclosed herein, the liquid content (e.g., "water content") may be a measured weight percentage of the liquid present in the composite material based on the total weight of the composite material.

[0065] In any of the methods disclosed herein, the liquid content in a composite material can be measured as a weight percentage of the liquid present in the composite material based on the total weight of the composite material. Any number of instruments for measuring the liquid (e.g., water) content in rubber materials, such as the coulometric Karl Fischer titration system or water balance manufactured by Mettler (Toledo International, Inc., Columbus, Ohio), are known in the art.

[0066] The amount of filler loaded into the mixture (on a dry weight basis) shall be at least 20 phr, at least 30 phr, at least 40 phr, or 20 phr to 250 phr, 20 phr to 200 phr, 20 phr to 180 phr, 20 phr to 150 phr, 20 phr to 100 phr, 20 phr to 90 phr, 20 phr to 80 phr, 30 phr to 200 phr, 30 phr to 180 phr, or 30 phr. The target can be ~150 phr, 30 phr~100 phr, 30 phr~80 phr, 30 phr~70 phr, 40 phr~200 phr, 40 phr~180 phr, 40 phr~150 phr, 40 phr~100 phr, 40 phr~80 phr, 35 phr~65 phr, or 30 phr~55 phr, or any other amount within or outside one or more of these ranges. The above phr amounts can also be applied to the filler dispersed in the elastomer (filler load). Other filler types, blends, combinations, etc., such as those disclosed in International Publication No. 2020 / 247663(A1), can be used, and such disclosures are incorporated herein by reference.

[0067] The wetting filler used in any of the methods disclosed herein may be a solid material, for example, a solid bulk material in the form of a powder, paste, pellets, cake, or slurry. The wetting filler may be at least 15% by weight of the total weight of the wetting filler, for example, at least 20% by weight, at least 25% by weight, at least 30% by weight, at least 40% by weight, at least 50% by weight, or 20% to 99% by weight, 20% to 95% by weight, 20% to 90% by weight, 20% to 80% by weight, 20% to 70% by weight, 20% to 60% by weight, 30% to 99% by weight, 30% to 95% by weight, 30% to 90% by weight, 30% to 80% by weight, 30% to 70% by weight, 30% by weight The liquid content may be %~60 wt%, 40 wt%~99 wt%, 40 wt%~95 wt%, 40 wt%~90 wt%, 40 wt%~80 wt%, 40 wt%~70 wt%, 40 wt%~60 wt%, 45 wt%~99 wt%, 45 wt%~95 wt%, 45 wt%~90 wt%, 45 wt%~80 wt%, 45 wt%~70 wt%, 45 wt%~60 wt%, 50 wt%~99 wt%, 50 wt%~95 wt%, 50 wt%~90 wt%, 50 wt%~80 wt%, 50 wt%~70 wt%, or 50 wt%~60 wt%. Other amounts of liquid content are disclosed in International Publication No. 2020 / 247663(A1), which is incorporated herein by reference.

[0068] The filler may be any conventional filler used in elastomers, such as reinforcing fillers. The filler may be particulate, fibrous, or plate-like. For example, particulate fillers are made from discrete materials. Such fillers can often have aspect ratios (e.g., length to diameter) of 3:1 or less, 2:1 or less, or 1.5:1 or less. Fibrous fillers can have aspect ratios of 2:1 or more, 3:1 or more, 4:1 or more, or higher. Typically, fillers used to reinforce elastomers have dimensions that are microscopic (e.g., several hundred microns or less) or nanoscale (e.g., less than 1 micron). In the case of carbon black, the discrete materials of particulate carbon black refer to aggregates or clusters formed from primary particles, and not the primary particles themselves. In other embodiments, the filler may have plate-like structures such as graphene and reduced graphene oxide.

[0069] The filler comprises at least one material selected from carbonaceous materials, carbon black, silica, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, pyrolytic carbon, graphene, graphene oxide, reduced graphene oxide, carbon nanotubes, single-walled carbon nanotubes, multi-walled carbon nanotubes, or combinations thereof, and coated and treated materials thereof; the filler comprises at least one material selected from carbon black, silica, and coated and treated materials thereof (e.g., carbon black and / or silica and / or silicon-treated carbon black), wherein at least 50% by weight of the filler is selected from carbon black and coated and treated materials thereof, and at least 90% by weight of the filler is selected from carbon black and coated and treated materials thereof.

[0070] The carbon black used in any of the methods disclosed herein can be any grade of reinforcing carbon black and semi-reinforcing carbon black. Examples of ASTM grade reinforcing grades are N110, N121, N134, N220, N231, N234, N299, N326, N330, N339, N347, N351, N358, and N375 carbon blacks. Examples of ASTM grade semi-reinforcing grades are N539, N550, N650, N660, N683, N762, N765, N774, N787, N990 carbon black and / or thermal black of N990 grade.

[0071] The carbon black can have any statistical thickness specific surface area (STSA) such as in the range of 20 m 2 / g to 250 m 2 / g or more. The STSA (statistical thickness specific surface area) is determined based on ASTM test procedure D-5816 (measured by nitrogen adsorption). The carbon black can have a compression oil absorption (COAN) in the range of about 30 mL / 100 g to about 150 mL / 100 g. The compression oil absorption (COAN) is determined in accordance with ASTM D3493. As an option, the carbon black can have an STSA in the range of 60 m 2 / g to​​​​​As described above, carbon black may be rubber black, particularly reinforced or semi-reinforced grade carbon black. Carbon blacks available from Cabot Corporation under the trademarks Regal®, Black Pearls®, Spheron®, Sterling®, Propel®, Endure®, and Vulcan®; carbon blacks available from Birla Carbon (formerly available from Columbia Chemicals) under the trademarks Raven®, Statex®, Furnex®, and Neotex®; and carbon blacks available from Orion Engineered Carbons (formerly Evonik and Degussa Industries) under the trademarks Corax®, Durax®, Ecorax®, and Purex®, as well as other fillers suitable for use in rubber or tire applications, can also be used in various embodiments. Suitable chemically functionalized carbon blacks include those disclosed in International Publication No. 96 / 18688 and U.S. Patent Application Publication No. 2013 / 0165560, which are incorporated herein by reference. A mixture of any of these carbon blacks may be used. Carbon blacks having ASTM grade and surface area and structure exceeding typical values, selected for mixing with rubber, such as those described in U.S. Patent Application Publication No. 2018 / 0282523, whose disclosure is incorporated herein by reference, may be used in wetting fillers and composite materials prepared by any of the methods disclosed herein.

[0073] Carbon black can be furnace black, gas black, thermal black, acetylene black, or lamp black, plasma black, recovered carbon black (e.g., as defined in ASTMD8178-19), or carbon products containing silicon-containing species and / or metal-containing species. Carbon black can be a multiphase aggregate containing at least one carbon phase and at least one metal-containing species phase or silicon-containing species phase, i.e., silicon-treated carbon black. In silicon-treated carbon black, silicon-containing species such as silicon oxides or carbides are distributed over at least a portion of the carbon black aggregate as an intrinsic part of the carbon black. Silicon-treated carbon black is not a coated or otherwise modified carbon black aggregate, but in fact corresponds to a two-phase aggregate particle. One phase is carbon, still existing as graphite microcrystalline and / or amorphous carbon, while the second phase is silica, and possibly other silicon-containing species. Thus, the silicon-containing species phase of silicon-treated carbon black is an intrinsic part of the aggregate distributed over at least a portion of the aggregate. Ecoblack® silicon-treated carbon black is available from Cabot Corporation. The manufacture and properties of these silicon-treated carbon blacks are described in U.S. Patent No. 6,028,137, which is incorporated herein by reference.

[0074] With respect to fillers, as one option, fillers consisting of at least silica (e.g., at least 50% by weight of silica), one or more types of silica, or any combination of silica can be used in any embodiment disclosed herein. Silica may include, or may be, precipitated silica, fumed silica, silica gel, and / or colloidal silica. Silica may be untreated silica and / or chemically treated silica, or may include them. Silica may be suitable for reinforcing elastomer composites, and about 20 m 2 / g~about 450m 2 / g; approx. 30m 2 / g~about 450m 2 / g; approx. 30m2 / g~about 400m 2 / g; or approximately 60ml 2 / g ~ approx. 250m 2 / g, approx. 60m 2 / g ~ approx. 250m 2 / g, approx. 80m 2 / g~about 200m 2 Silica can be characterized by its Brunauer-Emmett Teller surface area (BET, multipoint BET nitrogen adsorption, as determined by ASTM D1993) per gram. 2 / g~250m 2 / g, for example, about 80mg 2 / g~200m 2 / g or 90ml 2 / g~200m 2 / g, 80m 2 / g~175m 2 / g, or 80m 2 / g~150m 2STSA can be in the range of / g. Highly dispersible precipitated silica can be used as a filler in this method. Highly dispersible precipitated silica ("HDS") is understood to mean any silica that has substantial ability to deaggregate and disperse in an elastomer matrix. Such dispersion measurements may be observed by known methods using an electron microscope or optical microscope on a thin section of the elastomer composite material. Examples of commercially available grade HDS include Perkasil® GT3000GRAN silica from WR Grace & Co, Ultrasil® 7000 silica from Evonik Industries, Zeosil® 1165MP, 1115MP, Premium, and 1200MP silica from Solvay SA, Hi-Sil® EZ 160G silica from PPG Industries, Inc., and Zeopol® 8741 or 8745 silica from Evonik Industries. Conventional non-HDS precipitated silica can also be used. Examples of commercially available conventional precipitated silica include Perkasil® KS 408 silica from WR Grace & Co., Zeosil® 175 GR silica from Solvay SA, Ultrasil® VN3 silica from Evonik Industries, and Hi-Sil® 243 silica from PPG Industries, Inc. Precipitated silica using surface-bonded silane coupling agents may also be used. Examples of commercially available chemically treated precipitated silica include Agilon® 400, 454, or 458 silica from PPG Industries, Inc., and Coupsil silica from Evonik Industries, such as Coupsil® 6109 silica.

[0075] Other suitable fillers include carbon nanostructures (CNS, single CNS), multiple carbon nanotubes (CNTs), for example, multiple CNTs crosslinked into a polymer structure by branching in a dendritic manner, intertwining, entangling, and / or sharing a common wall with one another. CNS fillers are described in U.S. Patent No. 9,447,259 and International Publication No. 2021 / 247,153, the disclosures of which are incorporated herein by reference. Other suitable fillers include bio-derived or bio-based materials (derived from biosources), recycled materials, or other fillers that are considered renewable or sustainable, such as hydrothermal carbon (HTC, the filler includes lignin treated by hydrothermal carbonization as described in U.S. Patent Nos. 1,003,5957 and 1,042,8218, the disclosures of which are incorporated herein by reference), rice husk silica, carbon from methane pyrolysis, modified polysaccharide particles, starch, siliceous soil, crumb rubber, and functionalized crumb rubber. Examples of modified polysaccharides include those described in U.S. Patent Application Publications 2020 / 0181370 and 2020 / 0190270, the disclosures of which are incorporated herein by reference. For example, the polysaccharides can be selected from compositions comprising poly-α-1,3-glucan; poly-α-1,3-1,6-glucan; water-insoluble α-(1,3-glucan) polymers having 90% or more α-1,3-glycosidic bonds, less than 1% by weight of α-1,3,6-glycosidic branching points, and a number-average degree of polymerization in the range of 55 to 10,000; dextran; poly-α-1,3-glucan ester compounds and water-insoluble cellulose having a weight-average degree of polymerization (DPw) of about 10 to about 1000 and a cellulose II crystalline structure. As an option, at least one filler can be selected from rice husk silica, lignin, nanocellulose, hydrothermal carbon, and modified polysaccharides.

[0076] Suitable fillers are also disclosed in International Publication No. 2020 / 247663(A1), which is incorporated herein by reference.

[0077] With respect to solid elastomers used and mixed with wetting fillers, the solid elastomer can be considered a dry elastomer or substantially a dry elastomer. Based on the total weight of the solid elastomer, the solid elastomer may have a liquid content (e.g., solvent or water content) of 5% by weight or less, for example, 4% by weight or less, 3% by weight or less, 2% by weight or less, 1% by weight or less, or 0.1% to 5% by weight, 0.5% to 5% by weight, 1% to 5% by weight, 0.5% to 4% by weight. The solid elastomer (e.g., starting solid elastomer) may be entirely elastomer (starting liquid, e.g., water content of 5% by weight or less), or it may be an elastomer containing one or more fillers and / or other components.

[0078] Any solid elastomer can be used in this method. Examples of elastomers include natural rubber (NR), functionalized natural rubber, synthetic elastomers such as styrene-butadiene rubber (SBR, e.g., solution SBR (SSBR), emulsion SBR (ESBR), or oil-extracted SSBR (OESSB+R)), functionalized styrene-butadiene rubber, polybutadiene rubber (BR), functionalized polybutadiene rubber, polyisoprene rubber (IR), ethylene-propylene rubber (EPDM), isobutylene elastomers (e.g., butyl rubber), halogenated butyl rubber, polychloroprene rubber (CR), nitrile rubber (NBR), hydrogenated nitrile rubber (HNBR), fluoroelastomers, perfluoroelastomers, and silicone rubber, e.g., natural rubber, and blends thereof, e.g., natural rubber, styrene-butadiene rubber, butadiene rubber, and blends thereof, e.g., blends of the first and second solid elastomers. Other synthetic polymers that can be used in this method (either alone or in blends) include hydrogenated SBR and thermoplastic block copolymers (e.g., renewable ones). Examples of synthetic polymers include copolymers of ethylene, propylene, styrene, butadiene, and isoprene. Other synthetic elastomers include those synthesized by metallocene chemistry, where the metal is selected from Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Tm, Yb, Lu, Co, Ni, and Ti. Polymers made from bio-based monomers, such as modern carbon-containing monomers as defined by ASTM D6866, for example, polymers made from bio-based styrene monomers disclosed in U.S. Patent No. 9,868,853 (the disclosure of which is incorporated herein by reference), or polymers made from bio-based monomers such as butadiene, isoprene, ethylene, propylene, farnesene, and their comonomers can also be used. When using two or more elastomers, the two or more elastomers can be filled into the mixer simultaneously as a blend (in one or more fillings), or the elastomers can be added separately in any order and amount.For example, the solid elastomer may include natural rubber blended with one or more of the elastomers disclosed herein, such as butadiene rubber and / or styrene-butadiene rubber, or SBR blended with BR. For example, additional solid elastomers may be added separately to the mixer, and natural rubber may be added separately to the mixer.

[0079] The solid elastomer may be or may contain natural rubber. If the solid elastomer is a blend, it may contain at least 50% by weight, at least 70% by weight, or at least 90% by weight of natural rubber. The blend may further contain synthetic elastomers such as styrene-butadiene rubber, functionalized styrene-butadiene rubber, and polybutadiene rubber, and / or one or more of any other elastomers disclosed herein.

[0080] Additives may also be incorporated into the mixing process (e.g., whether it is a single-stage mixing or the second or third stage of a multi-stage mixing), and the additives may include degradation inhibitors and one or more rubber chemicals that enable the dispersion of fillers into the elastomer. Rubber chemicals as defined herein include processing aids (e.g., various oils and plasticizers, waxes, etc., for facilitating the mixing and processing of rubber), activators (e.g., zinc oxide and fatty acids, for activating the vulcanization process), accelerators (e.g., sulfenamides and thiazoles, for accelerating the vulcanization process), vulcanizing agents (or curing agents for crosslinking rubber, e.g., sulfur, peroxides), and other rubber additives, for example, but not limited to, retarders, aids, compounding accelerators, adhesion accelerators (e.g., cobalt salts for accelerating the adhesion of steel cords to rubber elastomers). The rubber chemical comprises one or more of the following: the use of (for example, as described in U.S. Patent No. 5,221,559 and U.S. Patent Application Publication No. 2020 / 0361242, the disclosure of which is incorporated herein by reference), resins (e.g., tackifiers, traction resins), flame retardants, colorants, foaming agents, and additives for reducing heat buildup (HBU). Optionally, the rubber chemical may include processing aids and activators. Alternatively, one or more other rubber chemicals may be selected from zinc oxide, fatty acids, zinc salts of fatty acids, waxes, accelerators, resins, and process oils.

[0081] As an option, at least a portion of the mixing under power control in the second mixer is carried out after the addition of at least one additive (one or more additives), for example, any of the additives disclosed herein, for example, at least one degradation inhibitor and / or processing aid (e.g., various oils and plasticizers, waxes) and / or activator (e.g., zinc oxide and / or fatty acids) and / or accelerator and / or resin and / or processing oil.

[0082] Using the methods disclosed, various wetting fillers, solid elastomers, and optionally additional drying fillers and other additives can be mixed, as described in International Publication No. 2020 / 247663(A1), the disclosure of which is incorporated herein by reference.

[0083] Any method for producing a composite material disclosed herein may further include one or more of the following steps after the formation of the composite material. One or more holding steps, One or more drying steps can be used to further dry the composite material to obtain a dried composite material. One or more extrusion processes, One or more calendering processes, One or more grinding steps to obtain a pulverized composite material, One or more granulation processes, One or more cutting steps, One or more packaging steps to obtain a packaged product or mixture, The packaged mixture or product can be broken apart to form a granulated mixture, and / or One or more mixing or blending steps, and / or One or more sheet-forming processes.

[0084] As a further example, the following series of steps can be performed, and after the formation of the composite material, each step can be repeated any number of times (with the same or different settings). One or more holding steps to achieve further elasticity, One or more cooling steps, A process of further drying the composite material to obtain an even more dried composite material. A process of mixing or compounding composite materials to obtain a compound mixture, A process of grinding the blended mixture to obtain a pulverized mixture (for example, a roll mill), A process of granulating the crushed mixture, Optionally, a process is taken to obtain a packaged mixture by packaging the mixture after granulation. An optional process of breaking apart and mixing the packaged mixture.

[0085] Additionally or alternatively, the composite material may be compounded with one or more additives disclosed herein, such as degradation inhibitors, zinc oxide, fatty acids, zinc salts of fatty acids, waxes, accelerators, resins, processing oils, and / or curing agents, and vulcanized to form a vulcanized product. Such vulcanized compound may have one or more improved properties, for example, one or more improved rubber properties, for example, but not limited to, improved hysteresis in a tire, wear resistance and / or rolling resistance, or improved mechanical strength and / or tensile strength, or improved tanδ and / or improved tensile stress ratio.

[0086] One or more articles may include materials made from composite materials or vulcanized products disclosed herein. Composite materials can be used to manufacture elastomer or rubber-containing products. As an option, elastomer composite materials may be used, or manufactured for use, to form vulcanized products incorporated into, for example, various components of a tire, such as tire treads (on-road or off-road tire treads, etc.) including caps and bases, undertreads, inner liners, tire sidewalls, tire carcasses, tire sidewall inserts, tire wire skims, and retreaded tire cushioning rubber, as well as pneumatic and non-pneumatic or solid tires. Alternatively or additionally, elastomer composite materials (and subsequent vulcanized products) may be used in hoses, seals, gaskets, weatherstrips, windshield wipers, automotive parts, liners, pads, housings, wheels and track elements, tire sidewall inserts, tire wire skims, and retreaded tire cushioning rubber, as well as pneumatic and non-pneumatic or solid tires. Alternatively or additionally, elastomer composites (and subsequent vulcanized products) can be used in hoses, seals, gaskets, vibration damping articles, track pads for truck propulsion systems such as trucks and bulldozers, engine mounts, seismic damping devices, mining equipment such as screens, mining equipment linings, conveyor belts, chute liners, slurry pump liners, mud pump components such as impellers, valve seats, valve bodies, piston hubs, piston rods, plungers, impellers for various applications such as mixed slurry and slurry pump impellers, grinding mill liners, cyclones and liquid cyclones, expansion joints, marine equipment such as linings for pumps (e.g., dredging pumps and outboard motor pumps), hoses (e.g., dredging hoses and outboard motor hoses), and other marine equipment, shaft seals for ships, oil, aerospace, and other applications, propeller shafts, linings for piping for transporting oil sands and / or tar sands, and other applications where wear resistance and / or improved dynamic properties are desired.Furthermore, elastomer composites can be used via vulcanized elastomer composites in rollers, cams, shafts, pipes, vehicle bushings, or other applications where wear resistance and / or improved dynamic properties are desired.

[0087] Accordingly, articles include vehicle tire treads including caps and bases, sidewalls, undertreads, inner liners, wire skim components, tire carcasses, engine mounts, bushings, conveyor belts, vibration dampers, weatherstrips, windshield wipers, automotive parts, seals, gaskets, hoses, liners, pads, housings, and wheels or track elements. For example, articles may be multi-component treads as disclosed in U.S. Patents 9,713,541, 9,713,542, 9,718,313, and 10,308,073, which are incorporated herein by reference. [Examples]

[0088] The water content in the released composite material was measured using a moisture balance (model: HE53, manufacturer: Mettler Toledo NA, Ohio). The composite material was sliced ​​into small pieces (size: length, width, height < 5 mm), and 2–2.5 g of material was placed on a disposable aluminum disc / plate, which was then placed inside the moisture balance. The weight loss was recorded at 125°C for 30 minutes. At the end of the 30 minutes, the moisture content of the composite material was recorded as follows:

number

[0089] Small amounts of organic volatile substances (<0.1% by weight) may be included in the moisture content test results.

[0090] The following tests were used to obtain performance data for each vulcanized material. The tensile stress at 100% elongation (M100) and 300% elongation (M300) was evaluated according to ASTM D412 (Test Method A, Die C) at 23°C, 50% relative humidity, and a crosshead speed of 500 mm / min. Tensile strain was measured using an extensometer. The ratio of M300 / M100 is called the tensile stress ratio (or modulus ratio). Elongation at fracture and tensile strength were also measured according to ASTM D412. The maximum tanδ was measured using an ARES-G2 rheometer (manufacturer: TA Instruments) in torsional mode with an 8 mm diameter parallel plate shape. The vulcanized specimen had a diameter of 8 mm and a thickness of approximately 2 mm. The rheometer was operated at a constant temperature of 60°C and a constant frequency of 10 Hz. Strain sweeps were performed at strain amplitudes from 0.1% to 68%. Measurements were taken at 10 points for each decimal point, and the measured maximum tanδ ("maximum tanδ") was reported, also referred to as "tanδ" unless otherwise specified. G'(10%)(MPa) is the dynamic storage modulus G' at 10% strain. The Payne difference of the compound was calculated from the difference between the dynamic storage modulus G' at 0.1% strain and G' at 50% strain, i.e., G'(0.1%)-G'(50%). The Mooney value was measured using a Montech VMV3000 instrument (Montech USA LLC, Columbia City, Indiana) set to the ML(1+4)@100C Mooney profile (large rotor, 1 minute preheating, 4 minute test). Shore A hardness was measured according to ASTM D2240 (1997) on vulcanized rubber samples with a thickness of 6 mm or more at 23°C.

[0091] Example 1 Example 1 describes the preparation of a composite material and vulcanized product comprising an 80 / 20 blend of natural rubber (RSS3) and butadiene rubber, with a target loading amount of 51 phr of wet carbon black filler, and the mixing was performed using PID output control for a portion of the mixture.

[0092] Examples 2 and 3 Examples 2 and 3 describe the preparation of composite materials and vulcanized products containing an 80 / 20 blend of natural rubber (RSS3) and butadiene rubber, similar to Example 1 (using PID output control for a portion of the mixture), with additional process modifications to further reduce batch time.

[0093] Comparative Example In the comparative example, mixing was performed using the same formulation as in Example 1, but no PID output control was performed at the first stage of mixing.

[0094] For Examples 1-3 and the Comparative Example, carbon black was prepared by grinding Propel® X25 carbon black (Cabot Corporation) and re-wetting it in a pin pelletizer to obtain a moisture content of approximately 56%. The natural rubber used was standard grade natural rubber RSS3 (Sri Trang Group, Thailand). Technical descriptions of these natural rubbers are widely available, such as in Rubber World Magazine's Blue Book published by Lippincott and Peto, Inc. (Akron, Ohio, USA). The butadiene rubber used was Buna® CB22 butadiene rubber ("CB22").

[0095] All composite materials were prepared by a two-stage mixing process. For Examples 1 and 2 and the comparative examples, the first stage was carried out using a BB-16 tangent mixer ("BB-16"; Kobelco Kobe Steel Group) equipped with two tangent four-blade rotors (4WN type) providing a capacity of 16.2 L. The first stage mixing in Example 3 and all second stage mixing were carried out using a BB-16 mixer equipped with two six-blade tangent rotors (6WI type) providing a capacity of 14.4 L.

[0096] For Examples 1-3, the first stage of mixing was performed using PID output control after each addition of filler. The proportionality constant was 200%, the integral constant was 5 seconds, and no differential control was used. The output setpoint was 75 kW (6.4 kW / kg, dry basis), and the maximum output of the output PID control loop was set to 100 rpm. The output input signal used by the output PID control loop was filtered by using a Kalman filter with a K2 constant of 0.005 (see Appendix 1). The control system performed these calculations approximately every 0.2 seconds. A first stage of mixing without output PID control was also performed after each addition of filler and after the addition of the degradation inhibitor (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine "6PPD"), with the rotor speed fixed at 80 rpm (Comparative Example). In Examples 1, 2 and the Comparative Example, 6PPD was added during the first mixing stage. After adding 6PPD, the mixtures of Example 1 and Example 2 were mixed at 100 rpm using output PID control before completion. In Example 3, 6PPD was added during the second mixing stage.

[0097] Table 1 provides the first and second stage mixing conditions for the comparative examples and the samples of Examples 1-3. [Table 1]

[0098] Table 2 shows the first-stage mixing protocol for the comparative example samples. The ram position ("ram position") is indicated as up or down. "Float" indicates that there is no hydraulic pressure on the ram. In the float position, the ram descends significantly due to its own weight. [Table 2]

[0099] Table 3 shows the first-step mixing protocol for the sample of Example 1. [Table 3]

[0100] Table 3 shows specific portions of the batch sequence executed under PID control. As can be seen from the figure, there are portions of the sequence that operate in fixed rpm mode. This is in contrast to the sequence in Table 2, which shows that all portions of the sequence operate in fixed rpm mode. From Table 1, it can be seen that the batch time for the first stage mixing of Example 1 under PID control is shorter compared to the comparative example sample mixed without PID control.

[0101] Figures 1 and 2 show the mixing curves for the first stage mixing of the Comparative Example (Figure 1) and the first stage mixing of Example 1 (Figure 2). Figure 1 shows plots of the output curve 12, rotor speed curve 14, and temperature curve 16 (y-axis) as a function of batch time (x-axis) for the first stage mixing of the Comparative Example. The ram position (unitless) is indicated by plot 18, where the maximum value indicates when the ram is operating at its highest level (e.g., "ram up") and the minimum value indicates when the ram is operating at its lowest level (e.g., "ram down"). Similarly, for the mixing of Example 1, Figure 2 shows plots of the output curve 22, rotor speed curve 24, and temperature curve 26 (y-axis) as a function of batch time (x-axis). The ram position (unitless) is indicated by plot 28, where the maximum value indicates when the ram is operating at its highest level and the minimum value indicates when the ram is operating at its lowest level. The numbers at the top of each of Figures 1 and 2 refer to the process numbers in Tables 2 and 3, respectively.

[0102] For the first stage of mixing in the comparative example (Figure 1), the power curve 12 includes a power peak 12a (batch time approximately 170 seconds) resulting from the first carbon black addition (corresponding to step 3 in Table 2), the subsequent ram reduction, and the subsequent increase in mixer speed to 80 rpm (step 4 in Table 2). Power peak 12a results in high-speed steam generation from the mixer. However, the power at peak 12a is close to the maximum safe level for operating this particular mixer. Rotor speeds higher than 80 rpm increase the steam generation rate, resulting in potentially dangerous operating conditions.

[0103] Figure 2 shows the output curve 22 obtained from the first stage of mixing operated with output control (Example 1). The output curve 22 has a peak 22a (batch time approximately 200 seconds) that occurs after the first filler addition (corresponding to step 3 in Table 3). The output peak 22a is similar in value to the output peak 12a of the comparative example mixing. However, the output PID control loop automatically increases the rotor speed so that the maximum output is achieved at a more gradual rate, making a higher rotor speed of 100 rpm possible (see the maximum value in rotor speed curve 24).

[0104] In the comparative example mixture (Figure 1), an additional power peak 12b (batch time approximately 300 seconds) is also observed in power curve 12 after the second carbon black addition (step 6 in Table 2). Power peak 12b and the subsequent power usage are lower compared to peak 12a after the first carbon black addition (step 2). These lower values ​​differ from the power profile of the first-stage mixture in Example 1. Power curve 22 (Figure 2) also features a second power peak 22b (batch time approximately 315 seconds) after the second carbon black addition (corresponding to step 7 in Table 3). However, this second power peak 22b is comparable in value to power peak 22a after the first carbon black addition. This is a result of the output PID control loop, which automatically increases the mixer speed to achieve the power setpoint. Furthermore, after power peak 22b, high power usage is maintained by the action of the output PID control loop. As a result, the "ram-down" mixing time between the second carbon black addition and the next filling (6PPD addition, step 9 in Table 3) is shorter than in the comparative example. This shorter time interval is largely responsible for the mixing in Example 1, which has a shorter first-stage batch time than the mixing in the comparative example. Example 1 also has a shorter batch time when the combined first and second-stage batch times are used (see Table 1).

[0105] Even if there are differences in the power curves and rotor speed curves from the mixture of the comparative example and Example 1, the respective temperature curves 16 and 26 are essentially the same.

[0106] Tables 4 and 5 provide the first-stage mixing protocols for Examples 2 and 3, respectively. [Table 4] [Table 5]

[0107] From the protocols in Tables 4 and 5, it can be seen that the first-stage mixing in Examples 2 and 3 was carried out in the same manner as in Example 1 (see Table 3), except that the first carbon black additive was added together with the rubber in step 1. This increased the filling rate in steps 1 and 2, resulting in a shorter ram-down mixing time before the second carbon black addition. However, if the mixing between the first and second carbon black additions were performed at a fixed speed, a low speed should be used to ensure that the initial power peak is below a safe maximum level. However, since most of the mixing between the first and second carbon black additions was performed under power PID control, the mixer speed was automatically optimized. The mixer speed was automatically reduced during the initial power peak and then automatically accelerated as carbon black incorporation progressed. This automatic optimization of the mixer speed reduced the batch time. The first-stage mixing time in Example 3 was further reduced by postponing the addition of 6PPD until the second-stage mixing.

[0108] Within 20 minutes of the completion of the first stage of mixing, all second stage mixing was performed in a BB-16 equipped with two 6-blade tangential rotors (6WI type) providing a 14.4 L capacity. All second stage mixing was performed with the ram raised to its highest position and using temperature PID control, i.e., the mixer rotor speed was automatically adjusted by the PID controller to target a certain temperature setpoint. The PID parameters were 100% proportional, 5-second integral, and no derivative. The temperature control setpoint was 135°C, and the maximum output of the temperature PID control loop was set to 60 rpm for Example 1 and 70 rpm for Examples 2 and 3. The protocols for the second stage mixing are provided in Table 6 (for Comparative Examples and Example 1), Table 7 (Example 2), and Table 8 (Example 3). [Table 6] [Table 7] [Table 8]

[0109] The composite material was compounded in two stages in a BB-2 tangential mixer ("BB-2"; Kobelco Kobe Steel Group). The BB-2 had two 4-blade tangential rotors (Type 4WN) providing a 1.5 L capacity. In the first compounding stage, the following chemicals were added: 3.0 phr of zinc oxide, 2.0 phr of stearic acid, 0.5 phr of 6PPD, 1.5 phr of TMQ (1,2-dihydro-224-trimethylquinoline), and 1.5 phr of wax beads. In the second compounding stage, 1.4 phr of TBBS (N-tert-butyl-2-benzothiazole sulfenamide) and 1.2 phr of sulfur were added as curing agents. After compounding, the mixture was sheeted to a thickness of 2.4 mm on a two-roll mill operating at 60°C. The sample was then incinerated at 150°C for 30 minutes at 100 kg / cm². 2 The mixture was cured under the specified pressure. The properties of the resulting compound / vulcanized product are shown in Table 9. [Table 9] * Payne difference = G'(0.1%) - G'(50%)

[0110] Tables 1 and 9 show that the properties of the vulcanized products of Examples 1-3 are similar to those of the comparative formulations. Table 1 shows that the first stage of mixing with power control (Examples 1 and 2) reduces the first stage mixing time (and therefore the total time for composite material preparation). The corresponding vulcanized product of Example 1 achieved similar rubber properties to the vulcanized product made from the comparative composite material. It can be seen that power control successfully reduced the mixing time without impairing the rubber properties at all.

[0111] The use of the terms “a,” “an,” and “the” should be interpreted as encompassing both singular and plural forms unless otherwise indicated herein or explicitly refuted by the context. The terms “comprising,” “having,” “including,” and “containing” should be interpreted as open-ended terms (i.e., “listed, but not limited to”) unless otherwise indicated herein. The enumeration of value ranges herein is merely intended to serve as an abbreviation for each individual value falling within that range, unless otherwise indicated herein, and each individual value is incorporated herein as if it were individually listed herein. All methods described herein may be performed in any preferred order unless otherwise indicated herein or explicitly refuted by the context. Any and all examples or exemplary language provided herein (e.g., “etc.”) is merely intended to better illustrate the invention and does not impose any limitation on the scope of the invention unless otherwise claimed. No language in this specification should be construed as indicating any unclaimed element essential to the implementation of the invention. Appendix 1: Explanation of the Kalman filter variable: P = Process variable (filtered by the control system) Filtered estimate of E=P (Calculated by the control system for each time increment of x) R = Rate of change of P over time (Calculated by the control system for each time increment of x) t = time x = the increment of time used by the control system (for data input, calculation, and data output) K2 = Filter constant input to the control system by the user. Filter constants calculated from K1=K2 equation: K1=2(K2) ** 0.5-K2 Et = Et - x + Rt - x + K1(Pt - Et - x - Rt - x) Rt = Rt - x + K²(Pt - Et) remarks: Initial estimates of E and R should be made (values ​​of 0 are often acceptable). K2 is empirically selected by the user to obtain the desired filtering of P. The following embodiments can be cited as examples of the present invention. (Note 1) A method for preparing a composite material, (a) A step of filling a mixer having one or more rotors with at least one solid elastomer and a wetting filler comprising a filler and a liquid present in an amount of at least 15% by weight based on the total weight of the wetting filler, (b) A step of mixing the at least one solid elastomer and the wetting filler in one or more mixing steps to form a mixture, and removing at least a portion of the liquid from the mixture by evaporation, in at least one of the mixing steps, the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) At least one of the following is applied: one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time; (c) a step of discharging the composite material from the mixer in a loading amount of at least 20 phr, the composite material having a liquid content of 10% by weight or less based on the total weight of the composite material, A method in which one or more rotors are mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under output control, wherein the rotational speed of one or more rotors is controlled by a controller which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint. (Note 2) The method according to Appendix 1, wherein at least a portion of the mixing in step (b) is performed under PID output control. (Note 3) The method according to Appendix 1 or 2, wherein the output setting point is in the range of 1 to 10 kW / kg when expressed as a specific output. (Note 4) (i) The method according to any one of the appendices 1 to 3, wherein the controller continuously calculates the difference between the measured mixer motor output and the output setpoint. (Note 5) The method according to Appendix 4, wherein the controller calculates the difference between the measured mixer motor output and the output setpoint at a set time interval in the range of 0.05 seconds to 5 seconds. (Note 6) The method according to Appendix 4, wherein the controller calculates the difference between the measured mixer motor output and the output setpoint at a set time interval in the range of 0.05 seconds to 1 second. (Note 7) (ii) The method according to any one of the appendices 1 to 6, wherein the controller continuously adjusts the rotational speed of one or more rotors when the measured mixer motor output deviates from the output setpoint. (Note 8) The method according to any one of the appendices 1 to 7, wherein the controller automatically calculates the difference between the measured mixer motor output and the output setpoint, and adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint. (Note 9) The method according to any one of the appendices 1 to 8, wherein the mixer is filled with the solid elastomer, and the mixing is performed under power control after the wetting filler has been filled into the mixer. (Note 10) The method according to Appendix 9, wherein the method comprises filling the mixer with at least two portions of the wetting filler, and the mixing is performed under power control after the first portion of the wetting filler has been filled into the mixer. (Note 11) The method according to Appendix 10, wherein the mixing is performed under output control after each portion of the wetting filler has been filled into the mixer. (Note 12) The method according to Appendix 10 or 11, wherein the first of the at least two portions of the wetting filler is at least 50% by weight of the total amount of the wetting filler to be filled into the mixer. (Note 13) The method according to any one of the appendices 1 to 12, wherein the solid elastomer is kneaded before filling the mixer with at least a portion of the wetting filler. (Note 14) The method according to any one of the appendices 1 to 12, wherein the solid elastomer is not kneaded before filling the mixer with at least a portion of the wetting filler. (Note 15) The method according to any one of the appendices 1 to 14, wherein the filler comprises at least one material selected from carbonaceous materials, carbon black, silica, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, pyrolysis carbon, graphene, graphene oxide, reduced graphene oxide, carbon nanotubes, single-walled carbon nanotubes, multi-walled carbon nanotubes, and combinations thereof, as well as coated and treated materials thereof. (Note 16) The method according to any one of the appendices 1 to 15, wherein the filler is selected from rice husk silica, lignin, nanocellulose, hydrothermal carbon, and modified polysaccharides, as well as combinations thereof, and coated and treated materials thereof. (Note 17) The method according to any one of the appendices 1 to 15, wherein the filler is selected from carbon nanostructures. (Note 18) The method according to any one of the appendices 1 to 15, wherein the filler is selected from carbon black, silica, silicon-treated carbon black, and blends thereof. (Note 19) The method according to any one of the appendices 1 to 15, wherein the filler is selected from carbon black, silicon-treated carbon black, and blends thereof. (Note 20) The method according to any one of the appendices 1 to 15, wherein at least 50% of the filler is selected from carbon black, silicon-treated carbon black, and blends thereof. (Note 21) The method according to any one of the appendices 1 to 20, wherein the solid elastomer is selected from natural rubber, functionalized natural rubber, styrene-butadiene rubber, functionalized styrene-butadiene rubber, polybutadiene rubber, functionalized polybutadiene rubber, polyisoprene rubber, ethylene-propylene rubber, isobutylene-based elastomer, polychloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polysulfide rubber, polyacrylate elastomer, fluoroelastomer, perfluoroelastomer, silicone elastomer, and blends thereof. (Note 22) The method according to any one of the appendices 1 to 21, wherein the one or more rotors are selected from a two-blade rotor, a four-blade rotor, a six-blade rotor, an eight-blade rotor, and one or more screw rotors. (Note 23) The method according to any one of the appendices 1 to 21, wherein the one or more rotors are selected from a 4-blade rotor, a 6-blade rotor, and an 8-blade rotor. (Note 24) The method according to any one of the appendices 1 to 21, wherein one or more rotors are selected from cross-reverse rotors. (Note 25) The method according to any one of the appendices 1 to 24, wherein the mixing time, defined as the filling time in (a) up to the release time in (c), is in the range of 1 to 9 minutes. (Note 26) The method according to any one of the appendices 1 to 25, wherein the mixing time, defined as the filling time in (a) up to the release time in (c), is in the range of 3 to 6 minutes. (Note 27) The method according to any one of the appendices 1 to 26, wherein the wetting filler has a liquid present in an amount of at least 20% by weight based on the total weight of the wetting filler. (Note 28) The method according to any one of the appendices 1 to 26, wherein the wetting filler has a liquid present in an amount ranging from 40% to 65% by weight based on the total weight of the wetting filler. (Note 29) The method according to any one of the appendices 1 to 28, wherein the mixing is carried out in two or more mixing steps. (Note 30) The method according to any one of the appendices 1 to 29, wherein the mixer in (a) is a first mixer, and the method further comprises mixing at least a portion of the composite material from (c) in a second mixer. (Note 31) (a) The mixer is the first mixer, and the method is (d) A step of mixing at least a portion of the composite material from (c) in a second mixer, wherein the second mixer is provided under the following conditions: (i) Ram pressure of 5 psi or less; (ii) The ram rises to at least 75% of its highest level; (iii) The RAM operates in floating mode; (iv) The ram is positioned so as not to be in substantially contact with the mixture; (v) The mixer is Ramless; and (vi) A step which is carried out under at least one of the following conditions: the filling rate of the mixture is in the range of 25% to 70%; (e) The method according to any one of the appendices 1 to 29, further comprising the step of discharging the composite material from the second mixer having a liquid content of less than 3% by weight based on the total weight of the composite material. (Note 32) The method according to Appendix 30 or 31, wherein the first mixer and the second mixer are the same. (Note 33) The method according to Appendix 30 or 31, wherein the first mixer and the second mixer are different mixers. (Note 34) The method according to Appendix 30 or 31, wherein the first mixer and the second mixer together constitute a tandem mixer. (Note 35) The method according to Appendix 30 or 31, wherein the second mixer is ramless. (Note 36) The method according to any one of the appendices 31 to 35, wherein, for the mixing in (d), the second mixer operates under at least one of the conditions (i) to (vi) for at least 50% of the mixing time. (Note 37) The method according to any one of the appendices 30 to 36, wherein the second mixer has one or more rotors mechanically coupled to a mixer motor, and at least a portion of the mixing in the second mixer is performed under output control, wherein the rotational speed of the one or more rotors is controlled by a controller, which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of the one or more rotors if the measured mixer motor output deviates from the output setpoint. (Note 38) The method according to Appendix 37, wherein at least a portion of the mixing under output control in the second mixer is performed with the ram raised to at least 75% of its highest level. (Note 39) The method according to Appendix 37 or 38, wherein the mixing under output control in the second mixer is performed after the addition of at least one additive. (Note 40) A method for preparing a composite material, (a) A step of filling a first mixer having one or more rotors with at least one solid elastomer and a wetting filler comprising a filler and a liquid present in an amount of at least 15% by weight based on the total weight of the wetting filler, (b) A step of mixing the at least one solid elastomer and the wetting filler in one or more mixing steps to form a mixture, and removing at least a portion of the liquid from the mixture by evaporation, in at least one of the mixing steps, the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) At least one of the following applies: one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time. The process is performed under output control, wherein one or more rotors are mechanically coupled to a mixer motor, and at least a portion of the mixing in process (b) is controlled by a controller which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of the one or more rotors when the measured mixer motor output deviates from the output setpoint, and the rotational speed of the one or more rotors is controlled by the controller. (c) A step of discharging the mixture from the first mixer in a loading amount of at least 20 phr, the mixture having a liquid content reduced to less than the liquid content at the start of step (b), A method comprising the step of mixing the mixture from (d)(c) in a second mixer to obtain the composite material. (Note 41) A method for preparing a composite material, (a) A step of filling a first mixer having one or more rotors with at least one solid elastomer and a wetting filler comprising a filler and a liquid present in an amount of at least 15% by weight based on the total weight of the wetting filler, (b) A step of mixing the at least one solid elastomer and the wetting filler in one or more mixing steps to form a mixture, and removing at least a portion of the liquid from the mixture by evaporation, in at least one of the mixing steps, the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) At least one of the following is applied: one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time; (c) A step of discharging the mixture from the first mixer in a loading amount of at least 20 phr, the mixture having a liquid content reduced to less than the liquid content at the start of step (b), (d) A step of mixing the mixture from (c) in a second mixer to obtain a composite material, A method comprising the step (b) wherein the second mixer has one or more rotors mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under output control, wherein the rotational speed of the one or more rotors is controlled by a controller which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of the one or more rotors if the measured mixer motor output deviates from the output setpoint.

Claims

1. A method for preparing a composite material, (a) A step of filling a mixer having one or more rotors with at least one solid elastomer and a wetting filler comprising a filler and a liquid present in an amount of at least 15% by weight based on the total weight of the wetting filler, (b) A step of mixing the at least one solid elastomer and the wetting filler in one or more mixing steps to form a mixture, and removing at least a portion of the liquid from the mixture by evaporation, in at least one of the mixing steps, the following: (i) The mixer has at least one temperature control means that is set to a temperature Tz of 65°C or higher, and (ii) At least one of the following is applied: one or more rotors operate at a tip speed of at least 0.6 m / s for at least 50% of the mixing time; (c) A step of discharging the composite material from the mixer in a loading amount of at least 20 phr, the composite material having a liquid content of 10% by weight or less based on the total weight of the composite material, A method in which one or more rotors are mechanically coupled to a mixer motor, and at least a portion of the mixing in step (b) is performed under output control, wherein the rotational speed of one or more rotors is controlled by a controller which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint.

2. The method according to claim 1, wherein at least a portion of the mixing in step (b) is performed under PID output control.

3. The method according to claim 1 or 2, wherein the controller continuously calculates the difference between the measured mixer motor output and the output setting point at set time intervals ranging from 0.05 seconds to 5 seconds.

4. The method according to claim 1 or 2, wherein the controller continuously adjusts the rotational speed of one or more rotors when the measured mixer motor output deviates from the output setpoint.

5. The method according to claim 1 or 2, wherein the controller automatically calculates the difference between the measured mixer motor output and the output setpoint, and adjusts the rotational speed of one or more rotors if the measured mixer motor output deviates from the output setpoint.

6. The method according to claim 1 or 2, wherein the mixer is filled with the solid elastomer, and the mixing is performed under power control after the wetting filler has been filled into the mixer.

7. The method according to claim 6, wherein the method comprises filling the mixer with at least two portions of the wetting filler, and the mixing is performed under power control after the first portion of the wetting filler has been filled into the mixer.

8. The method according to claim 7, wherein the mixing is performed under output control after each portion of the wetting filler has been filled into the mixer.

9. The method according to claim 7, wherein the first of the at least two portions of the wetting filler is at least 50% by weight of the total amount of the wetting filler to be filled into the mixer.

10. The method according to claim 1 or 2, wherein the filler comprises at least one material selected from carbonaceous materials, carbon black, silica, nanocellulose, lignin, clay, nanoclay, metal oxides, metal carbonates, pyrolysis carbon, graphene, graphene oxide, reduced graphene oxide, carbon nanotubes, single-walled carbon nanotubes, multi-walled carbon nanotubes, and combinations thereof, as well as coated and treated materials thereof.

11. The method according to claim 1 or 2, wherein the filler is selected from rice husk silica, lignin, nanocellulose, hydrothermal carbon, and modified polysaccharides, as well as combinations thereof, carbon nanostructures, and materials coated and treated thereof.

12. The method according to claim 1 or 2, wherein the filler is selected from carbon black, silica, silicon-treated carbon black, and blends thereof.

13. The method according to claim 1 or 2, wherein the solid elastomer is selected from natural rubber, functionalized natural rubber, styrene-butadiene rubber, functionalized styrene-butadiene rubber, polybutadiene rubber, functionalized polybutadiene rubber, polyisoprene rubber, ethylene-propylene rubber, isobutylene-based elastomer, polychloroprene rubber, nitrile rubber, hydrogenated nitrile rubber, polysulfide rubber, polyacrylate elastomer, fluoroelastomer, perfluoroelastomer, silicone elastomer, and blends thereof.

14. The method according to claim 1 or 2, wherein the mixing is carried out in two or more mixing steps, the mixer in (a) is a first mixer, and the method further comprises mixing at least a portion of the composite material from (c) in a second mixer.

15. (a) The mixer is the first mixer, and the method is (d) A step of mixing at least a portion of the composite material from (c) in a second mixer, wherein the second mixer is provided under the following conditions: (i) Ram pressure of 5 psi or less; (ii) Ram rises to at least 75% of its highest level; (iii) RAM operates in floating mode; (iv) The ram is positioned so as not to be substantially in contact with the mixture; (v) The mixer is ramless; and (vi) A step which is carried out under at least one of the following conditions: the filling rate of the mixture is in the range of 25% to 70%; (e) The method according to claim 1 or 2, further comprising the step of discharging the composite material from the second mixer having a liquid content of less than 3% by weight based on the total weight of the composite material.

16. The method according to claim 15, wherein, with respect to the mixing in (d), the second mixer operates under at least one of the conditions (i) to (vi) for at least 50% of the mixing time.

17. The method according to claim 14, wherein the second mixer has one or more rotors mechanically coupled to a mixer motor, and at least a portion of the mixing in the second mixer is performed under output control, wherein the rotational speed of the one or more rotors is controlled by a controller, which (i) calculates the difference between a measured mixer motor output and an output setpoint, and (ii) adjusts the rotational speed of the one or more rotors if the measured mixer motor output deviates from the output setpoint.

18. The method according to claim 17, wherein at least a portion of the mixing under output control in the second mixer is performed with the ram raised to at least 75% of its highest level.

19. The method according to claim 17, wherein the mixing under output control in the second mixer is performed after the addition of at least one additive.

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