KR20040050051A - Filler-fiber composite - Google Patents

Abstract

PURPOSE: Filler-fiber composite material is characterized by using slake containing citric acid, using a surfactant, having morphological controllability, having 0.1-2micron of thickness of fiber and having 10-400micron of length of the fiber. Paper manufactured out of the filler-fiber composite material has desirable optical properties and physical properties. CONSTITUTION: Filler-fiber composite material is obtained by the steps of: (a) supplying slake containing citric acid to a first reactor; (b) making the slake react under carbon dioxide existing in the first reactor to manufacture calcium hydroxide calcium carbonate slurry converted partly; (c) making the calcium hydroxide calcium carbonate slurry react under the carbon dioxide existing in a second reactor to manufacture the calcium hydroxide calcium carbonate slurry converted partly; and then (d) making the calcium hydroxide calcium carbonate slurry react with fiber under the carbon dioxide existing in a third reactor.

Description

Filler-Fiber Composites {FILLER-FIBER COMPOSITE}

The present invention relates to filler-fiber composites, methods for their preparation, their use in the production of paper or cardboard products, and paper produced therefrom. More specifically, the present invention relates to filler-fiber composites characterized in that the form or particle size of the inorganic filler is determined before bonding to the fibers. More specifically, the present invention relates to PCC filler-fiber composites in which the desirable optical and physical properties of paper made from the filler-fiber composites of the present invention are realized.

Filling of fibrous fillers such as calcium carbonate, talc and clay onto fibers for subsequent production of paper and paper products has been an ongoing attempt. For some time, several successful methods have been used to deal with these issues. In order to allow the filler remaining in the web with the fiber web, a method of using a retainer, a method of precipitating directly on the fiber, a method of attaching the filler directly to the fiber surface, a method of mixing the fiber and the filler, drying Precipitating in untreated pulp, filling cellulose fiber, mixing high shear, fiber materials and calcium carbonate in a closed pressurized container with carbon dioxide, attaching filler by mechanical bonding, positively charged polymer The process using and the process using pulp fiber steel filled with calcium carbonate have been used to retain the fillers in the fibers for subsequent use in paper. Most fiber retention methods are expensive and inefficient.

Therefore, there is a need for a filler fiber composite and a method for producing a composite that is efficient in retaining filler and inexpensive to use paper machines.

Accordingly, it is an object of the present invention to produce filler-fiber composites. It is yet another object of the present invention to provide a method of making a filler-fiber composite. It is another object of the present invention to prepare filler-fiber composites that retain physical properties such as tensile strength, fracture length and internal bond strength. Another object of the present invention is to prepare filler-fiber composites that retain optical properties such as ISO opacity and pigment dispersion. Another object of the present invention is to provide filler-fiber composites which are particularly useful for paper and cardboard products.

Related technology

US Pat. No. 6,156,118 teaches the mixing of calcium carbonate fillers with P50 or finer size noil fibers.

U.S. Patent 5,096,539 teaches in-situ precipitation of inorganic fillers into undried pulp.

US Patent 5,223,090 teaches a cellulose fiber filling method that uses high shear mixing of crumb pulp during a carbon dioxide reaction.

US Pat. No. 5,665,205 teaches a method consisting of mixing a fiber pulp slurry and an alkali salt slurry in a contacting zone in a reactor, directly contacting carbon dioxide and the slurry and then mixing the filler to precipitate on the secondary pulp fibers.

US Pat. No. 5,679,220 teaches a continuous method for the on-site deposition of fillers in papermaking fibers in a fluid stream, where shear is applied to the gas phase to immediately complete the conversion of calcium hydroxide to calcium carbonate.

US Pat. No. 5,122,230 teaches a method of modifying hydrophilic fibers by in situ precipitation of substantially insoluble inorganic materials.

US Pat. No. 5,733,461 teaches a method for the recovery and utilization of fines present in the wastewater stream generated from the papermaking process.

US Pat. No. 5,731,080 teaches in situ precipitation characterized by the attachment of the majority of calcium carbonate to fine fibers by reliable and unreliable mechanical bonding, without binders or retention agents.

US Pat. No. 5,928,470 teaches a method of making metal oxide or metal hydroxide-modified cellulose pulp.

US Pat. No. 6,235,150 teaches a method for producing pulp fiber steel loaded with calcium carbonate of 0.4 micron to 1.5 micron particle size.

Ultimately, the problem of keeping filler materials such as calcium carbonate, ground calcium carbonate, clay and talc in the fibers to be used in paper has been addressed by several tests. However, no literature prior to this application describes filler fiber composites, methods for their preparation or their use in paper and paper products, in which the form of the filler is predetermined prior to introduction into the fiber.

Summary of the Invention

The present invention feeds a seed containing slake to a first stage reactor, and reacts the seed containing slake in a first stage reactor in the presence of carbon dioxide to produce a partially converted calcium hydroxide calcium carbonate slurry. Thereafter, the first partially converted calcium hydroxide calcium carbonate slurry was reacted in a two-stage reactor in the presence of carbon dioxide to prepare a second partially converted calcium hydroxide calcium carbonate slurry, and then partially converted calcium secondly. A filler-fiber composite comprising preparing a filler-fiber composite by reacting a hydroxide calcium carbonate slurry and fibers in a three stage reactor in the presence of carbon dioxide.

In another aspect, the present invention provides a seed-containing flakes in a one-stage reactor and reacts the seed-containing flakes in a one-stage reactor in the presence of carbon dioxide to produce a partially converted calcium hydroxide calcium carbonate slurry. The present invention relates to a filler-fiber composite comprising preparing a filler-fiber composite by reacting a partially converted calcium carbonate slurry and fibers in a two-stage reactor in the presence of carbon dioxide.

In another aspect, the present invention is to supply a citric acid-containing flakes in a one-stage reactor, and reacted the citric acid-containing flakes in a one-stage reactor in the presence of carbon dioxide to prepare a first converted calcium hydroxide calcium carbonate slurry Subsequently, the partially converted calcium hydroxide calcium carbonate slurry was reacted in a two-stage reactor in the presence of carbon dioxide to prepare a partially converted calcium hydroxide calcium carbonate slurry, and then partially converted calcium hydride. A filler-fiber composite comprising preparing a filler-fiber composite by reacting the hydroxide calcium carbonate slurry and fibers in a three-stage reactor in the presence of carbon dioxide.

In another aspect, the present invention is to supply a citric acid-containing flakes in a one-stage reactor, and reacted the citric acid-containing flakes in a one-stage reactor in the presence of carbon dioxide to prepare a first converted calcium hydroxide calcium carbonate slurry The first portion of the partially converted calcium hydroxide calcium carbonate slurry is then taken, and the fiber is added and reacted in a two-stage reactor in the presence of carbon dioxide to produce a calcium carbonate / fiber composite that acts as a heel. The second portion of the partially converted calcium hydroxide calcium carbonate slurry is then taken, followed by the addition of fibers and surfactants, followed by reaction in the presence of carbon dioxide to partially convert Ca (OH) ₂ / CaCO _3. / fiber material to the manufactured, and then, the second part of the converted Ca (OH) ₂ / CaCO ₃ / fiber material primarily in the presence of a carbon dioxide 3 In the reactor system by reacting a filler-fiber composite material relates to-filler, comprising: producing a fiber composite material.

In another aspect, the present invention is to supply a citric acid-containing flakes in a one-stage reactor, and reacted the citric acid-containing flakes in a one-stage reactor in the presence of carbon dioxide to prepare a first converted calcium hydroxide calcium carbonate slurry After taking the first portion of the partially converted calcium hydroxide calcium carbonate slurry, the fibers were added and reacted in a two-stage reactor in the presence of carbon dioxide to produce a calcium carbonate / fiber composite that acts as a heel, Take a second portion of the partially converted calcium hydroxide calcium carbonate slurry, and then add fiber and polyacrylamide and then react in the presence of carbon dioxide to partially convert the Ca (OH) ₂ / CaCO ₃ / fiber to _secondary After the material was prepared, partly converted Ca (OH) ₂ / CaCO ₃ / fiber material was converted in the presence of carbon dioxide. The present invention relates to a filler-fiber composite comprising reacting in a three-stage reactor to produce a filler-fiber composite.

Finally, the present invention feeds the citric acid-containing slake to the one-stage reactor, reacts the citric acid-containing slake in the one-stage reactor in the presence of carbon dioxide to produce CaCO ₃ hills, and then the sodium carbonate-containing slake is present in the presence of carbon dioxide. Was added to the heel material in the one-stage reactor to prepare a partially converted calcium hydroxide calcium carbonate slurry, and then the partially converted calcium hydroxide calcium carbonate slurry and the fibers were reacted in a two-stage reactor in the presence of carbon dioxide. A filler-fiber composite comprising making a fiber composite.

Fibers used in the present invention are defined as fibers made by correcting cellulose and / or mechanical pulp fibers (by any pulp corrector known in the pulp processing art). The thickness of the fibers is usually 0.1 to 2 microns and the length of the fibers is 10 to 400 microns and is further prepared according to US Pat. No. 6,251,222, which is incorporated herein by reference.

PCC precipitation with diversified forms

Continuous Flow Stirred Tank Reactor (CFSTR)

Scale-nohedral form

The first step in this method involves preparing a highly reactive Ca (OH) ₂ lime-milk slake and screening it to -325 mesh. This flake is placed in a stirred reactor, raised to the desired reaction temperature, and then 0.1% citric acid is added to the flake to prevent aragonite formation and then reacted with carbon dioxide gas. The reaction is stopped at the point where 10 to 40% reaction proceeds. This produces some converted Ca (OH) ₂ / CaCO ₃ slurry (approximately 20 wt% solids), in proportion to the carbon dioxide feed to maintain the desired conductivity (ion saturation) that gives the polyhedron crystals. It is fed into the reaction vessel. This reaction proceeds until stabilization of the process is achieved. Once the product has been stabilized (approximately 95% converted), it is then mixed with the diluted fibers (approximately 1.5% concentration) and water. The mixture is reacted with carbon dioxide gas to the end point pH 7. The products made using this method may contain from about 0.2 to about 99.8% polyhedral PCC to fiber, at 3 to 5% total solids.

The product has about 5 to about 11 m 2 / g specific surface area, about 3 to about 5% product solids, about 0.2 to about 99.8% PCC content, and is mostly in the form of a tetrahedron.

Aragonite form

The first step in this method involves making a highly reactive Ca (OH) ₂ lime oil slake and selecting it to -325 mesh. The concentration of this slake is approximately 15 wt%. The flakes are placed in a stirred reactor to reach the desired reaction temperature, followed by morphology and sizing by addition of about 0.05 to about 0.04% additives, followed by reaction with carbon dioxide gas. After the reaction proceeded by 10 to 40%, the reaction was stopped at this point. This produces a partially converted Ca (OH) ₂ / CaCO ₃ slurry, which is fed to the reaction vessel at a rate consistent with the carbon dioxide feed to maintain the desired conductivity (ion saturation) that produces acicular aragonite crystals. . This reaction is continued until stabilization of the process is achieved. Once the product has been stabilized (approximately 95% calcium carbonate), it is then mixed with diluted fibers (approximately 1.5% concentration) and water. Calcium carbonate and fibers are reacted with carbon dioxide gas to an end point pH 7.0. The product prepared using this method contains from about 0.2 to about 99.8% aragonite type PCC to the fiber at about 3% to about 5% of total solids.

The product has a specific surface area of about 5 to about 8 m 2 / g and a PCC content of about 0.2 to about 99.8% relative to about 3 to about 5 wt% product solids and fibers, most often in the form of aragonite.

Rhombohedral form

The first step in this method involves producing a highly reactive Ca (OH) ₂ lime oil slash, which is selected at -325 mesh and is approximately 20 wt% concentration. 0.1% citric acid is added to prevent aragonite formation. A portion of this flake is added to the stirred reactor, raised to the desired reaction temperature, and then carbonated with carbon dioxide gas. The reaction proceeds until the conductivity produces at least a "heel". "Hill" is defined as a fully converted calcium carbonate crystal with any crystal structure, usually having an average particle size in the range of about 1 to about 2.5 microns. Sodium carbonate is added to the remainder of the slake that was not used in the manufacture of the "hill" material. This slake and carbon dioxide are added to the "hill" material at a carbon dioxide feed rate to maintain the desired conductivity (ion saturation) to produce rhombohedral crystals. The reaction is continued until stabilization of the process is achieved. Once stabilization is achieved, this product (approximately 90-95% converted) is mixed with the diluted fibers (approximately 1.5% concentration) and water. Additional carbon dioxide was added until the end point pH 7.0. The product prepared using this method contains about 0.2 to about 99.8% rhombohedral PCC and has about 3 to about 5% total solids on the fiber.

The product has a specific surface area of about 5 to about 8 m 2 / g, about 3 to about 5% product solids, and about 0.2 to about 99.8% PCC content, mostly in the rhombohedral form.

Example

The following examples are intended to illustrate the invention, not to limit the scope of the invention.

Example 1

Single triangle triangular PCC

15 L of water and 3 kg of CaO were reacted at 50 ° C to prepare 20 wt% of Ca (OH) ₂ flake. Thereafter, Ca (OH) ₂ flakes were selected to -325 mesh to obtain the selected flakes, which were then placed in a 30 L double jacketed stainless steel first stage reactor being stirred at 615 rpm. Citric acid, 0.1 wt% of the total CaCO ₃ amount to be prepared theoretically, was placed in a selected slake in a 30 L reaction vessel, after which the temperature of the contents was increased to 40 ° C. 20% carbon dioxide gas (14.83 standard 1 minute carbon dioxide / 59.30 standard 1 minute air) in air was added to 30 L reaction vessel to prepare a 2: 1 Ca (OH) ₂ / CaCO ₃ slurry. At this point, the carbon dioxide supply was stopped and the slurry was placed in a 20 L stirred container.

Two liters of a 2: 1 Ca (OH) ₂ / CaCO ₃ slurry were placed in a double-jacketed one-stage reaction vessel made of stainless steel with 4 liters of stirring (1250 rpm). The temperature was set at 51 ° C. and 20% carbon dioxide gas (1.41 standard 1 minute carbon dioxide / 5.64 standard 1 minute air) in air was added to the 4 L one-step reaction vessel until the pH was 7.0 to make a CaCO ₃ slurry. Once the pH is 7.0, 20% carbon dioxide gas (1.41 standard l minute carbon dioxide / 5.64 standard l minute air) in air is continuously added to the 4 l first stage reaction vessel to maintain a conductivity of about 90% ion saturation. A 2: 1 Ca (OH) ₂ / CaCO ₃ slurry from a 20 L storage vessel was placed in a 4 L one stage reaction vessel. Continuous addition of Ca (OH) ₂ / CaCO ₃ slurry and carbon dioxide to a 4 L one-stage reaction vessel for 12 hours, when the physical properties of the product remained substantially unchanged, yielding a ca 98 ₃ converted CaCO ₃ slurry. made. 0.18 L of 98% CaCO ₃ slurry was placed in a double jacketed two-stage reaction vessel of stainless steel with 4 L stirring (1250 rpm), 0.66 L of cellulose fiber of dry weight 3.8 wt% was added and diluted to 1.5% concentration. It was. This mixture of CaCO ₃ slurry and fibers was reacted with 20% carbon dioxide (1.41 standard 1 minute carbon dioxide / 5.64 standard 1 minute air) in air to prepare a CaCO ₃ filler-fiber composite. Calcium carbonate fillers were mostly in the form of triangles.

Example 2

Aragonite PCC

15 wt% Ca (OH) ₂ flakes were prepared by reacting 10.5 L of water and 2.1 kg of CaO at 50 ° C. The Ca (OH) ₂ flakes were then selected to -325 mesh to make a choice of slake, which was then placed in a 30 L double jacketed stainless steel reaction vessel being stirred at 615 rpm. 0.1 wt% of a high surface area (HSSA) aragonite seed (surface area of about 40 m 2 / g, approximately 25% solids) was placed in a 30 L reaction vessel and the temperature of the contents was brought to 51 ° C. As the end point is reached, "seed" is defined as being completely converted to aragonite crystals that are milled to a high specific surface area (ie, at least 30 m 2 / g and typically 0.1 to 0.4 micron particle size). 10% carbon dioxide gas in air (5.24 standard liters of carbon dioxide / 47.12 standard liters of air) was added to a 30-liter stainless steel double jacket reaction vessel for 15 minutes, and then the carbon dioxide concentration was added to 20% (10.47 standard liters of air) in air. CO2 / 41.89 standard 1 min air) was increased for 15 minutes to make a 2.3: 1 Ca (OH) ₂ / CaCO ₃ slurry. At this time, the supply of carbon dioxide was stopped. A 2.3: 1 Ca (OH) ₂ / CaCO ₃ slurry was placed in a stirring 20 L storage container. Two liters of a 2.3: 1 Ca (OH) ₂ / CaCO ₃ slurry was placed in a double-jacketed stainless steel one-stage reaction vessel, stirred at 4250 1250 rpm, and the temperature was adjusted to 52 ° C. A 100% CaCO ₃ slurry was prepared by placing 20% carbon dioxide gas in air (1.00 standard 1 minute carbon dioxide / 3.99 standard 1 minute air) into a 4 L one-step reaction vessel and continuing until the pH reached 7.0. The temperature of the 100% CaCO ₃ slurry in the 4 L one stage reaction vessel was brought to 63 ° C. 20% carbon dioxide (1.00 standard liters of carbon dioxide / 3.99 standard liters of air) in air was added to the 4 liters of the one-stage reaction vessel while adding a 2.3: 1 Ca (OH) ₂ / CaCO ₃ slurry in a 20 liters storage vessel. litres were added to the first stage reaction vessel to maintain conductivity of approximately 90% ion saturation. The reaction was continued for approximately 9 hours until the physical properties of the resulting product remained essentially unchanged to produce a 98 wt% CaCO ₃ slurry.

0.35 L of 98 wt% CaCO ₃ slurry was placed in a double jacket two-stage reaction vessel of stainless steel, stirred at 4 L (1250 rpm), and 0.66 L of 3.8 wt% cellulose fiber and 1.0 L of water were added in 4 L of 2 Into the stage reactor, a 1.5 wt% CaCO ₃ / fiber mixture was prepared. 20% carbon dioxide in air (1.00 standard liters of carbon dioxide / 3.99 standard liters of air) is further added to a 4 liter two-stage reaction vessel until the pH is 7.0, at which point the reaction is completed, CaCO ₃ / fiber Composites were prepared. The composite consisted of approximately 75% aragonite type PCC for the fibers.

Example 3

Rhomboid PCC

15 wt of water and 3 kg of CaO were reacted at 50 ° C. to prepare a 20 wt% Ca (OH) ₂ slake. The Ca (OH) ₂ flakes were then selected to -325 mesh to make a choice of slake, which was then placed in a 20 L stirred container. Two liters of slake selected from the 20 liter storage vessel were placed in a double jacketed one-stage reaction vessel of stainless steel with 4 liter stirring, and stirring started at 1250 rpm. To a 4 L one-step reaction vessel was added 0.03 wt% citric acid per theoretical CaCO ₃ weight and the temperature of the contents was raised to 50 ° C. A 100% CaCO ₃ slurry was prepared by adding 20% carbon dioxide gas in air (1.44 standard 1 minute carbon dioxide / 5.77 standard 1 minute air) to a 4 L one-step reaction vessel until the pH was 7.0. Ca (OH) ₂ / Na ₂ CO ₃ flakes were prepared by adding 1.3 wt% Na ₂ CO ₃ solution based on the theoretical yield of CaCO ₃ to the selected slake in a 20 L storage container. While raising the temperature of the contents of the 4-liter one-stage reaction vessel to about 68 ° C. and adding 20 liters of Ca (OH) ₂ / Na ₂ CO ₃ flakes from the storage vessel to the 4-liter one-stage reactor, 20% carbon dioxide in air (1.44 standard liters of carbon dioxide / 5.77 liters of air) was added to the 4 liters one-stage reaction vessel to maintain a conductivity of about 50% ion saturation. Ca (OH) ₂ / Na ₂ CO ₃ flakes and carbon dioxide were added continuously for about 12 hours until the physical properties of the resulting product did not change essentially to produce a about 98 wt% CaCO ₃ slurry.

0.22 L of 98 wt% CaCO ₃ slurry was placed in a double jacket two-stage reaction vessel made of stainless steel with 4 L stirring (at 1250 rpm), and 0.66 L of 3.8 wt% cellulose fiber and 1.0 L of water were added in 4 L of 2 Into the stage reactor, a 1.5 wt% CaCO ₃ / fiber mixture was prepared. 20% carbon dioxide in air (1.44 standard liters of carbon dioxide / 5.77 standard liters of air) is added to an additional 4 liters in a two-stage reaction vessel until pH is 7.0, at which point the reaction is completed, about 3.4 wt% CaCO ₃ / fiber composites were prepared. Calcium carbonate was mostly rhombohedral.

Example 4

Polyhedron-CFSTR

15 L of water and 3 kg of CaO were reacted at 48 DEG C to prepare Ca (OH) ₂ slakes, and 6 L of water was further added to prepare 20 wt% Ca (OH) ₂ slakes. 20 wt% Ca (OH) ₂ flakes were selected at −325 mesh and then placed into a 30 L, double jacket, stainless steel reaction vessel being stirred at 615 rpm. Based on the total weight of CaCO ₃ to be prepared theoretically, 0.015% citric acid was placed in a 30 L reaction vessel and the temperature of the contents was adjusted to 36 ° C. Thirty liters of 20% carbon dioxide gas (13.72 standard liters of carbon dioxide / 54.89 standard liters of air) in air was placed in a reaction vessel of 30 liters to prepare a 5: 1 Ca (OH) ₂ / CaCO ₃ slurry. The carbon dioxide feed was stopped and the Ca (OH) ₂ / CaCO ₃ slurry was placed in a stirring 20 L storage container.

In a 4 L stirred container, 0.25 L of Ca (OH) ₂ / CaCO ₃ slurry was mixed with 0.66 L of 3.8 wt% fiber and 1.09 L of water to provide Ca (OH) ₂ / CaCO ₃ / fiber Material was prepared. 2 l Ca (OH) ₂ / CaCO ₃ / fiber material was placed in a 4 l stirred (1250 rpm) reaction vessel and the temperature was set at 55 ° C., followed by 20% carbon dioxide in air (1.30 standard l min carbon dioxide / 5.23 CaCO ₃ / fiber composites were prepared by carbonation to pH 7.0 with standard liter air). A separate 16 L 1.5 wt% fiber and 10 L water container were prepared. Stirring while maintaining a flow of carbon dioxide gas (1.30 standard l minutes carbon dioxide / 5.23 standard l minutes air) at a rate to maintain conductivity of about 90% ion saturation, and also maintaining a mass balance of about 4-5% total solids A Ca (OH) ₂ / CaCO ₃ slurry in a 20 L storage vessel and a 1.5% concentration fiber mixture were added to 4 L reaction vessel at 172.05 ml / min and further 31.21 ml / min water.

The reaction was continued until the physical properties of the product did not change essentially. The addition of material from the storage vessel was discontinued, the carbon dioxide continued to be added, and the addition of carbon dioxide was stopped when the pH of the material in the reaction vessel with 4 liters of stirring reached 7.0, resulting in CaCO ₃ having a clear triangular form. A 2.2: 1 CaCO ₃ / fiber composite was obtained containing.

Example 5

Polyhedron CFSTRs / Surfactants

15 L of water and 3 kg of CaO were reacted at 48 ° C. to produce Ca (OH) ₂ flakes, and then 6 L of water was further added to prepare 20 wt% Ca (OH) ₂ flakes. 20% Ca (OH) ₂ flakes were selected at -325 mesh and then placed in a 30 L reaction vessel (615 rpm agitation). Based on the weight of CaCO ₃ to be produced theoretically, 0.015% citric acid was added to the 30 L reaction vessel and the temperature of the contents was adjusted to 35 ° C. Thirty liters of 20% carbon dioxide gas (14.08 standard liters of carbon dioxide / 56.30 standard liters of air) in air were added to the 30 liters reaction vessel to prepare a 5: 1 Ca (OH) ₂ / CaCO ₃ slurry. At this point, the carbon dioxide feed was stopped and the Ca (OH) ₂ / CaCO ₃ slurry was placed in a 20 L stirred container.

In a 4 L stirred container, 0.25 L of Ca (OH) ₂ / CaCO ₃ slurry was mixed with 0.66 L of 3.8 wt% fiber and 1.09 L of water to give 2 L of Ca (OH) ₂ / CaCO ₃ / The fiber material was prepared.

2 L of Ca (OH) ₂ / CaCO ₃ / fiber material was placed in a 4 L double-jacketed stirred (1250 rpm) reaction vessel made of stainless steel, and its temperature was raised to 58 ° C. Ca (OH) ₂ / CaCO ₃ / fiber material and 20% carbon dioxide in air (1.30 standard l minute carbon dioxide / 5.23 standard l minute air) were reacted to pH 7.0.

At this point, 16 L of 1.5 wt% fiber (6.32 L and 9.68 L of water at 3.8% concentration) and 10 L of water container were separately prepared. Based on 1.5% fiber volume, 0.04% of surfactant was added. The surfactant is Tergitol ^™ MIN-FOAM 2X, available from Union Carbide, Danbury Old Ridgebury Road 39, 06817, Connecticut.

Once pH 7.0 is achieved in a 4 L reaction vessel, the carbon dioxide gas flow (1.30 standard l minute carbon dioxide / 5.23 standard l minute air) is maintained at a rate to maintain conductivity of about 90% ion saturation, and also from about 4 to While maintaining a mass balance of 5% total solids, the remaining 5: 1 Ca (OH) ₂ / CaCO ₃ slurry from a 20 L stirred container was 176.48 ml of 1.5% fiber mixture stream and 32.00 ml per minute. 4 L was added to the reaction vessel with 10 L of water from the vessel. Material was continuously added to the reaction vessel from the stirred storage vessel until the physical properties of the product did not change essentially. At the point where the physical properties of the product remained essentially unchanged, material addition from the storage vessel was stopped and carbon dioxide addition was continued until the pH reached 7.0, at which time carbon dioxide addition was stopped. This produces a 2.33: 1 CaCO ₃ / fiber composite containing calcium carbonate having a clear triangular form.

Example 6

Polyhedron CFSTR / Polyacrylamide

15 L of water and 3 kg of CaO were reacted at 48 ° C. to make Ca (OH) ₂ flakes, and then 6 L of water was further added to prepare 20 wt% Ca (OH) ₂ flakes. 20% Ca (OH) ₂ flakes were selected at -325 mesh and then placed into a 30 L stirred (615 rpm) reaction vessel. Based on the total weight of CaCO ₃ to be produced theoretically, 0.1% citric acid was added to the 30 L reaction vessel and the temperature of the contents was adjusted to 50 ° C. Thirty liters of 20% carbon dioxide gas (15.01 standard liters of carbon dioxide / 60.06 standard liters of air) in air was added to the 30 liters reaction vessel to prepare a 5: 1 Ca (OH) ₂ / CaCO ₃ slurry. The carbon dioxide feed was stopped and the slurry was placed in a 20 L stirred storage container. To a 4 L stirred vessel, 0.31 L of Ca (OH) ₂ / CaCO ₃ slurry, 0.60 L of 3.8 wt% concentration fiber and 1.09 L of water were added to prepare a Ca (OH) ₂ / CaCO ₃ / fiber material. . 2 L of Ca (OH) ₂ / CaCO ₃ / fiber material was placed in a 4 L stirred (1250 rpm) reaction vessel and its temperature was raised to 51 ° C. 20% carbon dioxide in air (1.34 standard l minutes carbon dioxide / 5.34 standard l minutes air) was added until the pH was 7.0 to prepare a CaCO ₃ / fiber composite.

At this point, 16 L of 1.5 wt% fiber (6.32 L and 9.68 L of water at 3.8% concentration) and 10 L of water container were separately prepared. 0.05% cationic polyacrylamide (Percol 292) was added based on the fiber volume at 1.5% concentration. Percol 292 is commercially available from Allied Colloids of 2434 Sulfork Willy Road 2301, Virginia.

Once pH 7.0 is achieved in a 4 L reaction vessel, the carbon dioxide gas flow (1.30 standard l minute carbon dioxide / 5.23 standard l minute air) is maintained at a rate to maintain conductivity of about 90% ion saturation, while also providing product concentration. While maintaining a mass balance of about 4-5% total solids, the remaining 5: 1 Ca (OH) ₂ / CaCO ₃ slurry remaining from the 20 L stirred container, with 1.5% fiber flow at 90 ml per minute and 48.5 per minute 4 liters with water, ml, were added to the stirred double jacketed reaction vessel. Material was continuously added to the reaction vessel from the stirred storage vessel until the physical properties of the product did not change essentially. The addition of the material from the 20 liter storage vessel was stopped, the carbon dioxide was added continuously until the pH was 7.0, and the addition of carbon dioxide was stopped at pH 7.0, resulting in 3.34 containing PCC in the form of a clear tetrahedron. A: 1 CaCO ₃ / fiber composite was prepared.

Control fibers of the present invention were corrected at the Empire State Paper Research Institute (ESPRI) using an Escher-Wyss (conical) refiner for 80 ° SR (freedom). As measured by the Fiber Quality Analyzer (arithmetic mean use), the control fibers were between 200 and 400 microns.

Control filler-fiber manufacturing method

Make a 15% solid slake and mix it with the fiber (~ 1.5% concentration). Reaction to the end point of pH 7.0 in the presence of carbon dioxide produces a filler-fiber composite having a surface area of 6 to 11 m 2 / g (about 60 to 80% PCC, but may be more or less in the composite).

Morphologically controlled filler-fiber composites exhibit comparable or better physical properties (ie tensile strength, fracture length, and internal bond strength) compared to control filler-fibers.

Morphologically controlled filler-fiber composites show comparable optical properties (ie ISO opacity and pigment dispersion) compared to control filler-fibers.

The present invention provides a filler-fiber composite and a process for preparing the same, wherein the filler-fiber composite comprises citric acid-containing flakes and is optionally prepared in multiple stages using surfactants. We present a filler-fiber composite in which properties, specifically morphological controllability, are realized.

Claims (48)

(a) feeding the citric acid-containing slake into the first stage reactor; (b) reacting the citric acid-containing flakes in a first stage reactor in the presence of carbon dioxide to prepare a partially converted calcium hydroxide calcium carbonate slurry (c) reacting the first partially converted calcium hydroxide calcium carbonate slurry in the presence of carbon dioxide in a two-stage reactor to prepare a second partially converted calcium hydroxide calcium carbonate slurry. (d) a filler-fiber composite comprising reacting the partially converted calcium hydroxide calcium carbonate slurry with fibril in the presence of carbon dioxide in a three-stage reactor to produce a filler-fiber composite. The filler-fiber composite of claim 1, wherein the fiber is about 0.1 to about 2 microns in thickness and the fiber is about 10 microns to about 400 microns in length. 3. The filler-fiber composite of claim 2, wherein the filler is a scalenohedral having a specific surface area of about 5 to about 11 m 2 / g. 4. The filler-fiber composite of claim 3, wherein the calcium hydroxide calcium carbonate slurry is about 20 to about 40% converted. 5. The filler-fiber composite of claim 4, wherein about 41 to about 99% of the primarily converted calcium hydroxide calcium carbonate slurry is converted. 6. The filler-fiber composite of claim 5, wherein the partially converted calcium hydroxide calcium carbonate slurry is converted to a filler-fiber composite. (a) feeding the citric acid-containing slake into the first stage reactor; (b) reacting the citric acid-containing flakes in the presence of carbon dioxide in a first stage reactor to produce a first partially converted calcium hydroxide calcium carbonate slurry (c) reacting the first partially converted calcium hydroxide calcium carbonate slurry in the presence of carbon dioxide in a two-stage reactor to prepare a second partially converted calcium hydroxide calcium carbonate slurry. and (d) reacting the partially converted calcium hydroxide calcium carbonate slurry with the fibers in the presence of carbon dioxide in a three-stage reactor to produce a filler-fiber composite. 8. The method of claim 7, wherein the fiber is about 0.1 to about 2 microns thick and the fiber is about 10 microns to about 400 microns long. 9. The method of claim 8, wherein the filler is triangular and has a specific surface area of about 5 to about 11 m < 2 > / g. 10. The method of claim 9, wherein the calcium hydroxide calcium carbonate slurry is about 20 to about 40% converted. The method of claim 10 wherein the first partially converted calcium hydroxide calcium carbonate slurry is about 41 to about 99% converted. 12. The method of claim 11 wherein the partially converted calcium hydroxide calcium carbonate slurry is converted to a filler-fiber composite. The filler-fiber composite of claim 1, wherein the filler-fiber composite is used for paper or paperboard. 8. The method of claim 7, wherein the filler-fiber composite is used for paper or paperboard. A paper made using the filler-fiber composite of claim 1. Paper produced using the filler-fiber composite manufacturing method of claim 7. (a) feeding the citric acid-containing slake into the first stage reactor; (b) reacting the citric acid-containing flakes in the presence of carbon dioxide in a first stage reactor to prepare a partially converted calcium hydroxide calcium carbonate slurry; (c) Take the first portion of the partially converted calcium hydroxide calcium carbonate slurry, add fibrils and react in a two-stage reactor in the presence of carbon dioxide to act as heel calcium carbonate / fibers After manufacturing the composite (d) Take a second portion of the partially converted calcium hydroxide calcium carbonate slurry, add fibril and surfactant, and then react in the presence of carbon dioxide to partially convert Ca (OH) ₂ / CaCO ₃ / After preparing the fibrous material (e) a filler-fiber composite, characterized by reacting a partially converted Ca (OH) ₂ / CaCO ₃ / fiber material in a three-stage reactor in the presence of carbon dioxide to produce a filler-fiber composite. 18. The filler-fiber composite of claim 17, wherein the fiber is about 0.1 to about 2 microns in thickness and the fiber is about 10 microns to about 400 microns in length. 19. The filler-fiber composite of claim 18, wherein the filler is of a tetrahedron shape having a specific surface area of about 5 to about 11 m < 2 > / g. 20. The filler-fiber composite of claim 19, wherein the calcium hydroxide calcium carbonate slurry is about 20 to about 40% converted. 21. The filler-fiber composite of claim 20, wherein the first partially converted calcium hydroxide calcium carbonate slurry is about 41 to about 99% converted. 22. The filler-fiber composite of claim 21, wherein the partially converted calcium hydroxide calcium carbonate slurry is converted to a filler-fiber composite. (a) feeding the citric acid-containing slake into the first stage reactor; (b) reacting the citric acid-containing flakes in a first stage reactor in the presence of carbon dioxide to prepare a partially converted calcium hydroxide calcium carbonate slurry (c) taking the first portion of the partially converted calcium hydroxide calcium carbonate slurry, and then adding fibrils and reacting in a two-stage reactor in the presence of carbon dioxide to produce a calcium carbonate / fiber composite that acts as a heel. next (d) taking a second portion of the partially converted calcium hydroxide calcium carbonate slurry, followed by the addition of fibril and surfactant followed by reaction in the presence of carbon dioxide, partially converted Ca (OH) ₂ / CaCO ₃ / fiber-fiber material, followed by reaction of the partially converted Ca (OH) ₂ / CaCO ₃ / fiber material in a three-stage reactor in the presence of carbon dioxide to produce a filler-fiber composite Characterized in that the filler-fiber composite manufacturing method. 24. The method of claim 23, wherein the fiber is about 0.1 to about 2 microns in thickness and the fiber is about 10 microns to about 400 microns in length. 25. The method of claim 24, wherein the filler is in the shape of a single triangle having a specific surface area of about 5 to about 11 m < 2 > / g. 27. The method of claim 25, wherein the calcium hydroxide calcium carbonate slurry is about 20 to about 40% converted. 27. The method of claim 26, wherein the first partially converted calcium hydroxide calcium carbonate slurry is about 41 to about 99% converted. 28. The method of claim 27, wherein the partially converted calcium hydroxide calcium carbonate slurry is converted to a filler-fiber composite. 18. The filler-fiber composite of claim 17, wherein the filler-fiber composite is used for paper or paperboard. 24. The method of claim 23 wherein the filler-fiber composite is used for paper or paperboard. Paper made using the filler-fiber composite of claim 17. A paper made using the filler-fiber composite method of claim 23. (a) feeding the citric acid-containing slake into the first stage reactor; (b) reacting the citric acid-containing flakes in the presence of carbon dioxide in a first stage reactor to prepare a partially converted calcium hydroxide calcium carbonate slurry; (c) Take the first portion of the partially converted calcium hydroxide calcium carbonate slurry, add fibril and react in a two-stage reactor in the presence of carbon dioxide to produce a calcium carbonate / fiber fiber composite that acts as a heel next (d) Take a second portion of the partially converted calcium hydroxide calcium carbonate slurry, add fibril and polyacrylamide, and then react in the presence of carbon dioxide to partially convert Ca (OH) ₂ /. CaCO ₃ / fiber fabric material is prepared (e) a filler-fiber composite, characterized by reacting a partially converted Ca (OH) ₂ / CaCO ₃ / fiber material in a three-stage reactor in the presence of carbon dioxide to produce a filler-fiber composite. 34. The filler-fiber composite of claim 33, wherein the fiber is about 0.1 to about 2 microns in thickness and the fiber is about 10 microns to about 400 microns in length. 35. The filler-fiber composite of claim 34, wherein the filler is of a polar triangle having a specific surface area of about 5 to about 11 m < 2 > / g. 36. The filler-fiber composite of claim 35, wherein the calcium hydroxide calcium carbonate slurry is about 20 to about 40% converted. 37. The filler-fiber composite of claim 36, wherein about 41 to about 99% of the primarily converted calcium hydroxide calcium carbonate slurry is converted. 38. The filler-fiber composite of claim 37, wherein the partially converted calcium hydroxide calcium carbonate slurry is converted to a filler-fiber composite. (a) feeding the citric acid-containing slake into the first stage reactor; (b) reacting the citric acid-containing flakes in the presence of carbon dioxide in a first stage reactor to prepare a partially converted calcium hydroxide calcium carbonate slurry; (c) Take the first portion of the partially converted calcium hydroxide calcium carbonate slurry, add fibril and react in a two-stage reactor in the presence of carbon dioxide to produce a calcium carbonate / fiber fiber composite that acts as a heel next (d) Take a second portion of the partially converted calcium hydroxide calcium carbonate slurry, add fibril and polyacrylamide, and then react in the presence of carbon dioxide to partially convert Ca (OH) ₂ /. CaCO ₃ / fiber fabric material is prepared (e) preparing a filler-fiber composite comprising the step of reacting a partially converted Ca (OH) ₂ / CaCO ₃ / fiber material in a three-stage reactor in the presence of carbon dioxide to produce a filler-fiber composite Way. 40. The method of claim 39, wherein the fibers are about 0.1 to about 2 microns thick and the fibers are about 10 microns to about 400 microns long. 41. The method of claim 40, wherein the filler is of a polar triangle having a specific surface area of about 5 to about 11 m < 2 > / g. 42. The method of claim 41, wherein the calcium hydroxide calcium carbonate slurry is about 20 to about 40% converted. 43. The method of claim 42, wherein the first partially converted calcium hydroxide calcium carbonate slurry is about 41 to about 99% converted. 44. The method of claim 43, wherein the partially converted calcium hydroxide calcium carbonate slurry is converted to a filler-fiber composite. 34. The filler-fiber composite of claim 33, wherein the filler-fiber composite is used for paper or paperboard. 40. The method of claim 39, wherein the filler-fiber composite is used for paper or paperboard. A paper made using the filler-fiber composite of claim 33. A paper made using the filler-fiber composite manufacturing method of claim 39.