阅读说明：本技术 一种环保纸及其制备方法 (Environment-friendly paper and preparation method thereof ) 是由 石勇 陈琪鸿 梁天华 于 2019-10-22 设计创作，主要内容包括：本发明公开了一种环保纸及其制备方法,所述环保纸的原料组份及重量份配比为：改性植物秸秆粉60-80份、贝壳粉10-15份、硅藻土3-5份、消泡剂2-3份、分散剂4-7份、去离子水150-200份。(The invention discloses environment-friendly paper and a preparation method thereof, wherein the environment-friendly paper comprises the following raw material components in parts by weight: 60-80 parts of modified plant straw powder, 10-15 parts of shell powder, 3-5 parts of diatomite, 2-3 parts of defoaming agent, 4-7 parts of dispersing agent and 200 parts of deionized water 150-.)

1. The environment-friendly paper is characterized by comprising the following raw materials in parts by weight: 60-80 parts of modified plant straw powder, 10-15 parts of shell powder, 3-5 parts of diatomite, 2-3 parts of defoaming agent, 4-7 parts of dispersing agent and 200 parts of deionized water 150-.

2. The environment-friendly paper as claimed in claim 1, wherein the defoamer is polyoxyethylene polyoxypropylene pentaerythritol ether or polyoxyethylene polyoxypropylene amine ether or polyoxypropylene glycerol ether, the dispersant is ammonium polyacrylate, sodium polyacrylate or stearic acid, the particle size of the modified plant straw powder, the shell powder and the diatomite is less than 50 nm, and the modified plant straw is selected from corn straw or wheat straw.

3. The environment-friendly paper as claimed in claim 1, wherein the modified plant straw powder is prepared by the following steps:

step A, preparing a modifier, wherein the raw material components and the weight part ratio of the modifier are 10-20 parts of light-cured resin, 4-7 parts of photoinitiator and 30-35 parts of absolute ethyl alcohol;

weighing the photocuring resin, placing the photocuring resin in a container, adding absolute ethyl alcohol, stirring for 30 minutes at the speed of 400 revolutions per minute of 300-one, stirring and mixing uniformly, raising the temperature to 40 ℃, starting to dropwise add the photosensitizer at the speed of 15-20 drops per minute to obtain a photocuring resin solution, after dropwise adding is finished, raising the temperature to 50 ℃, keeping the temperature, and continuously stirring for 3-4 hours to obtain a modifier photocuring resin stable solution;

b, pretreating the straws, crushing the straws by a wall breaking crusher, washing the straws to remove impurities, drying the straws in a drying box at the temperature of 50-55 ℃ for 3-4 hours to enable the moisture content of the straws to be 5%, grinding the straws for 40-50 minutes after drying in a planetary ball mill at the rotation speed of 400-450r/min, sieving the straws by a 200-mesh sieve, and taking undersize products to obtain straw powder;

step C, microbial fermentation; placing the straw powder prepared in the step B in a stirrer, adding a proper amount of deionized water and biological enzyme, wherein the addition amount of the biological enzyme is 1-2% of the weight of the straw powder, stirring at the rotating speed of 800-1000r/min for 40-50 minutes to obtain a straw powder mixed solution, placing the straw powder mixed solution in an ultrasonic oscillator, carrying out ultrasonic oscillation dispersion at 400-500W for 40-60 minutes to obtain an ultrasonic oscillation mixed solution, placing the ultrasonic oscillation mixed solution in a reaction kettle, adjusting the pH value to 7-8, pressurizing 5-6MPa, carrying out constant-temperature and constant-pressure biological fermentation reaction at the temperature of 35-55 ℃ for 30-40 hours, then cooling, washing, precipitating, pulping, grinding into pulp to obtain pulp A, wherein the concentration of the pulp A is 7-8%, the pulp forming degree is 50-60 degrees SR, the pulp grinding pressure is 0.5-1MPa, and the pulp grinding gap is 0.1-0.2 mm;

step D, vacuum impregnation; putting the slurry A obtained in the step C into an impregnation device, adding the modifier photocuring resin stable solution obtained in the step A, stirring for 5-10 minutes at the stirring speed of 600-650r/min for 20-30 minutes, vacuumizing and impregnating, keeping the vacuumizing state for 5-10 minutes, and recovering normal pressure to obtain impregnation slurry B;

and E, carrying out low-temperature freeze drying, namely freeze drying the dipping slurry B for 1-3 hours at the temperature of-5-10 ℃, crushing, grinding and granulating to obtain the modified plant straw powder.

4. A method for preparing the environment-friendly paper as claimed in claim 3, characterized by comprising the following steps:

step one, weighing raw materials;

step two, mixing raw materials for pulping;

step three, photocuring and forming;

and step four, drying to prepare base paper, coiling, hot-pressing and cutting.

Technical Field

The invention belongs to the technical field of papermaking, and mainly relates to environment-friendly paper and a preparation method thereof.

Background

China is a big agricultural country, the yield of straws can reach hundreds of millions of tons every year, and the huge resource is used as living energy in rural areas, most of the resources are abandoned on the ground or are burnt on the spot, and only a small part of the resources are used as feed or generate methane. The straw is composed of straw skin, straw pith and leaves, and the main components of the straw skin are cellulose and lignin; straw pulp contains a large amount of hemicellulose, starch and a small amount of protein components; the straw mainly contains crude protein, crude fat and saccharide.

At present, the papermaking raw materials in China mainly comprise wood, non-wood and waste paper. According to the measurement and calculation of China paper making society, in 2016, the wood pulp accounts for 23% of the total weight of the raw materials, the non-wood pulp accounts for 15%, and the waste paper pulp accounts for 62%. In recent years, the proportion of waste paper pulp is gradually increased, waste paper becomes an important resource for the development of the Chinese paper industry, and the circular economy characteristic of the sustainable development of the Chinese paper industry is more and more obvious.

The main components of the straw are cellulose, hemicellulose, lignin and the like, are very similar to paper materials, and have very stable properties at normal temperature and very slow degradation. The straw real density is about 1500 kg/m³If the straw-based composite filler is crushed and used for papermaking instead of an inorganic mineral filler, the density of paper can be reduced, strong bonding force can be generated between the straw-based composite filler and fibers, the surface strength, tensile strength, tearing strength and internal bonding strength of the paper can be improved to a certain extent, the recyclability of related paper types is remarkably improved, inorganic deinking sludge generated in the recycling process is greatly reduced, the recycled straw-based composite filler can be used for combustion to generate heat energy, the environment is protected, and the recycling of renewable resources can be realized, so that the straw-based composite filler has certain development and application prospects in the papermaking industry.

However, since the main components of the straw are cellulose, hemicellulose, lignin, pectin, crude protein, ash and the like, and a large amount of alcoholic hydroxyl groups are arranged on the surface of the straw, when the straw is used for papermaking filling, the strength of paper is higher than that of an inorganic mineral filler, but when the straw is used for paper requiring higher strength, a satisfactory effect cannot be achieved.

The paper fiber and filler modification technology provides renewable organic fillers based on natural resources, mainly including starch-based fillers and sawdust fillers, but also indicates that the development and application of the renewable organic fillers based on natural resources still have limitations, so that the feasibility of the renewable organic fillers is limited, and some technical problems are inevitably generated in the production and application processes. This document does not suggest the possibility of using straw as renewable organic filler, not to mention the technical solutions disclosed for its implementation.

Disclosure of Invention

In order to overcome the above problems in the prior art, the present inventors have conducted extensive studies and extensive experiments to provide the following technical solutions.

The environment-friendly paper comprises the following raw material components in parts by weight: 60-80 parts of modified plant straw powder, 10-15 parts of shell powder, 3-5 parts of diatomite, 2-3 parts of defoaming agent, 4-7 parts of dispersing agent and 200 parts of deionized water 150-.

The defoaming agent is polyoxyethylene polyoxypropylene pentaerythritol ether or polyoxyethylene polyoxypropylene amine ether or polyoxypropylene glycerol ether, the dispersing agent is ammonium polyacrylate, sodium polyacrylate or stearic acid, the particle size of the modified plant straw powder, the shell powder and the diatomite is less than 50 nanometers, and the modified plant straw is selected from corn straw or wheat straw.

The preparation method of the modified plant straw powder comprises the following steps:

step A, preparing a modifier, wherein the raw material components and the weight part ratio of the modifier are 10-20 parts of light-cured resin, 4-7 parts of photoinitiator and 30-35 parts of absolute ethyl alcohol; the light-cured resin is selected from acrylate resin or honey; the viscosity of the light-cured resin is 100 centipoises; the resin monomer used by the acrylate resin is selected from one or more of polyethylene glycol diacrylate, ethylene glycol dimethacrylate, epoxy acrylic resin, polyurethane acrylic resin, polyester acrylic resin and amino acrylic resin; the acrylate monomers listed contain two or more reactive functional groups;

the photoinitiator is selected from one or more of 2-hydroxy-2 methyl-1-phenyl-1-acetone, 1-hydroxycyclohexyl phenyl ketone, benzoin dimethyl ether, benzophenone, alpha-hydroxy ketone, benzoyl formate or acyl phosphine oxide, ethyl 2,4, 6-trimethylbenzoylphenylphosphonate (TPO-L), benzoin and derivatives, benzil, alkyl benzophenones, acyl ortho oxide, benzophenones and thioxanthones;

weighing the photocuring resin, placing the photocuring resin in a container, adding absolute ethyl alcohol, stirring for 30 minutes at the speed of 400 revolutions per minute of 300-one, stirring and mixing uniformly, raising the temperature to 40 ℃, starting to dropwise add the photosensitizer at the speed of 15-20 drops per minute to obtain a photocuring resin solution, after dropwise adding is finished, raising the temperature to 50 ℃, keeping the temperature, and continuously stirring for 3-4 hours to obtain a modifier photocuring resin stable solution;

b, pretreating the straws, namely crushing the straws by a wall breaking crusher, wherein the length of the straws is 1-2 cm, cleaning to remove impurities, putting the straws into a drying box, drying at the temperature of 50-55 ℃ for 3-4 hours to ensure that the water content of the straws is 5%, putting the straws into a planetary ball mill after drying, grinding for 40-50 minutes under the condition that the rotating speed is 400-450r/min, sieving by a 200-mesh sieve, and taking undersize substances to obtain straw powder;

step C, microbial fermentation; placing the straw powder prepared in the step B in a stirrer, adding a proper amount of deionized water and biological enzyme, wherein the addition amount of the biological enzyme is 1-2% of the weight of the straw powder, stirring at the rotating speed of 800-1000r/min for 40-50 minutes to obtain a straw powder mixed solution, placing the straw powder mixed solution in an ultrasonic oscillator, carrying out ultrasonic oscillation dispersion at 400-500W for 40-60 minutes to obtain an ultrasonic oscillation mixed solution, placing the ultrasonic oscillation mixed solution in a reaction kettle, adjusting the pH value to 7-8, pressurizing 5-6MPa, carrying out constant-temperature and constant-pressure biological fermentation reaction at the temperature of 35-55 ℃ for 30-40 hours, then cooling, washing, precipitating, pulping, grinding into pulp to obtain pulp A, wherein the concentration of the pulp A is 7-8%, the pulp forming degree is 50-60 degrees SR, the pulp grinding pressure is 0.5-1MPa, and the pulp grinding gap is 0.1-0.2 mm;

the biological enzyme is one or more of pectinase, protease, xylanase, brown rot fungus, soft rot fungus and white rot fungus; in the process, the straw powder starts to decompose under the action of the biological enzyme, and most of lignin is opened;

step D, vacuum impregnation; putting the slurry A obtained in the step C into an impregnation device, adding the modifier photocuring resin stable solution prepared in the step A, stirring for 5-10 minutes at the stirring speed of 600-650r/min for 20-30 minutes, vacuumizing and impregnating, keeping the vacuumizing state for 5-10 minutes, and recovering normal pressure to obtain impregnation slurry B;

and E, carrying out low-temperature freeze drying, namely freeze drying the dipping slurry B for 1-3 hours at the temperature of-5-10 ℃, crushing, grinding and granulating to obtain the modified plant straw powder.

The preparation method of the environment-friendly paper comprises the following steps:

step one, weighing raw materials according to the proportion of the raw materials;

step two, mixing raw materials for pulping; respectively adding the powder into deionized water, stirring at the rotating speed of 500-600r/min for 30-40 minutes to obtain paper pulp slurry A; putting the raw material particles pretreated in the step (1) into a pulper, adding a proper amount of water, and pulping under the ultrasonic condition of a specific frequency, wherein the concentration of the pulp is controlled to be 6-7%; a. weighing 0.6-0.7 part of montmorillonite, and putting the montmorillonite into an environment with the temperature of-20 to-4 ℃ for freezing treatment for 20-30 min;

b. b, putting the montmorillonite subjected to the freezing treatment in the operation a into a microwave oven for activation treatment for 60-70 s;

c. putting the montmorillonite subjected to the activation treatment in the operation b into white vinegar with the mass fraction of 8-10 mL, and stirring to obtain montmorillonite suspension for later use;

step three, photocuring and forming; and (3) papermaking the pulp slurry into paper sheets by using a paper machine, synchronously carrying out ultraviolet irradiation for 4-5 minutes at the irradiation wavelength of 230-260nm and the irradiation distance of 10-11cm, and drying under the vacuum condition at the drying temperature of 25-30 ℃ and the drying water content of 2-3%.

And step four, drying to prepare base paper, coiling, hot-pressing and cutting.

The design idea of the application is as follows:

the method is characterized in that plant straw fibers are used as a substrate, the reaction conditions are accurately controlled, electrostatic force, coordination and hydrogen bond are used as driving forces, the nano plant straw fibers and a modifier are stacked on the surfaces of the fibers in a stacked and alternate mode for multiple times, the modifier is arranged in an ordered mode, the surface structure of the fibers is complicated, and the reacted fibers are used for papermaking, so that the stacked enhanced paper base is prepared.

Modifying plant straw fibers by a modifier containing a light-cured resin and a photosensitizer to obtain modified plant straw powder, directly mixing the modified plant straw powder with other raw materials to obtain slurry in the process of preparing paper, solidifying the product by illumination, and obtaining the paper product by drying, pressing and other process steps, wherein the process is simpler, the preparation is more convenient and the environment is protected; according to the method and the product, the product can be cured only by illumination, the process is simpler and is not limited by equipment, the curing strength of the product is high, and the obtained environment-friendly paper has better performance than the traditional paper, and can be specifically referred to a performance parameter table.

The technical route of the application is as follows:

the process mechanism of the method comprises the chemical adsorption and the physical adsorption in the stacking reaction process, and can be summarized into electrostatic force, coordination and hydrogen bond action between pulp fibers and a modifier. The modifier surface is positively charged and the pulp surface is negatively charged, so that electrostatic attraction plays an important role in the lamination adsorption process. Meanwhile, the surface of the modifier contains a large number of amino groups, carboxylate ions on the surface of the pulp fibers can react with the amino groups to form new chemical bonds, and in addition, the modifier is combined on the surface of the pulp fibers due to hydrogen bonds. This application has obvious advantage for single electrostatic attraction, and it is bigger to generate drive power, helps forming more stable orderly nanostructure fast on fibre surface, makes fibre surface complicated, increases the chemical bond structure between the paper pulp fibre, and the combining action between the increase fibre finally improves the intensity that the fibre becomes paper.

The method for vacuum impregnation of the paper pulp fibers is adopted, the modified plant straws of the ingredients are good in modification effect, the product performance parameters of the obtained environment-friendly paper are high, the ordered arrangement of the nanoscale one-dimensional materials on the surfaces of macroscopic fibers can be realized, the complicated fiber surface structure is realized, the operation is simple, and the efficiency is high. The modifier with opposite charges is alternately deposited on the surface of the paper pulp fiber to form an ordered multilayer structure so as to improve the physical properties of the paper, which is not reported at present.

The process of modifying the modifier by the plant straw fiber needs to be regulated and controlled by necessary accurate process, ordered generation of microscopic nano particles on the surface of macroscopic fiber is realized, the surface structure of the fiber is complicated, and thus the reinforced paper base generated by stacking is prepared. The biological fermentation treatment is carried out on the plant straws, so that the physical size of the fiber is reduced, the content of carboxyl and amino on the surface of the fiber is increased, the generated driving force is increased, the ordered generation and accumulation of oppositely charged nano-cellulose on the surface of the cellulose are ensured, the surface structure of the cellulose is complicated, the interlayer binding force is improved, and the paper forming strength is improved.

This application adopts freeze drying, mainly removes the water in the straw to make subsequent preparation process more accurate, this is very important to the growth of control modified plant straw powder, the modified plant straw powder that the preparation particle size is little and the granularity is even.

The mixing device used in the application comprises a base, a supporting telescopic shaft, a power seat, a lifting power device, a material lifting mixing mechanism, a power plugging device and fixed stirring components, wherein the supporting telescopic shaft is installed on the base, the power seat is arranged on the supporting telescopic shaft, the power seat is connected with a power disc through a driving shaft, the lifting power device is arranged at the center of the lower part of the power disc, a plurality of stirring blade assemblies are installed on the lifting power device, the material lifting mixing mechanism is installed below the lifting power device, a plurality of slurry inlet through grooves are formed in the material lifting mixing mechanism, the power plugging device is installed on the material lifting mixing mechanism through a spring, sealing blocks matched with the slurry inlet through grooves are arranged on the power plugging device, and a plurality of fixed stirring components are uniformly distributed at the periphery of the lower part of the power disc; the material lifting and mixing mechanism further comprises a material lifting cylinder body, a connecting frame and a mixed material mixing device, the material lifting cylinder body is in a hemispherical shell shape, a slurry inlet through groove is formed in the material lifting cylinder body, sliding grooves are symmetrically formed in two sides of the slurry inlet through groove, the power plugging device penetrates through the sliding grooves, the material lifting cylinder body is connected with a lifting frame of a lifting power device through the connecting frame, the connecting frame is evenly distributed in a circumferential mode, the mixed material mixing device is arranged on the outer wall of the material lifting cylinder body along the bus direction of the material lifting cylinder body, the number of the mixed material mixing devices is 2-3, and the included angle between the mixed material mixing devices is 60-90 degrees.

Advantageous effects

The invention extracts cellulose and plant fiber from corn stalk, mixes the plant fiber with aluminum ion and copper ion in water solution, and carries out biological fermentation reaction under high temperature and high pressure, so that the plant fiber is activated and organic acid is generated, high glycan in the fiber is decomposed to generate monosaccharide, polysaccharide and furfural, the mechanical property of the fiber component is improved, then the organic component is mixed with diatomite, covalent bond forms more compact adsorption effect, silicon element in the straw fiber component is separated out and combined to generate silicon dioxide, silicon carbide and other components, the strength and toughness of the paper are further improved, and the invention has wide application prospect.

Compared with a scanning electron microscope image of common commercially available base paper, the scanning electron microscope image of the environment-friendly paper prepared by the raw materials and the method can show that fibers of the common commercially available base paper in the figure 1 are mutually interwoven, but more and larger gaps appear among the fibers, the fibers at the gaps are separated from the fibers, and the separated fibers cannot form hydrogen bonds and cannot contribute to bonding strength; in the figure 2, the fibers of the paper are mutually interwoven, the modified straws are used, and the diatomite fills gaps between the fibers to generate a bridging effect between the fibers, so that the fibers are indirectly combined with each other, the bonding strength between the fibers is improved, and the strength performance of the paper is improved.

Drawings

FIG. 1 is a scanning electron micrograph of a conventional commercially available base paper;

FIG. 2 is a scanning electron microscope image of the eco-paper according to example 1 of the present application.

Detailed Description