Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C41/00—Shaping by coating a mould, core or other substrate, i.e. by depositing material and stripping-off the shaped article; Apparatus therefor
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/18—Manufacture of films or sheets
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/04—Oxygen-containing compounds
  • C08K5/05—Alcohols; Metal alcoholates
  • C08K5/053—Polyhydroxylic alcohols
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/02—Cellulose; Modified cellulose
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L39/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a single or double bond to nitrogen or by a heterocyclic ring containing nitrogen; Compositions of derivatives of such polymers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L5/00—Compositions of polysaccharides or of their derivatives not provided for in groups C08L1/00 or C08L3/00
  • C08L5/04—Alginic acid; Derivatives thereof
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers

Definitions

• the present invention relates to a method for producing a cellulose nanofiber film.
• CNF cellulose nanofibers
• CNF can be formed into a film by coating on a paper substrate or the like.
• CNF has a gel-like structure even at a low solid content concentration and exhibits a very high viscosity. Therefore, it is difficult to obtain a desired film from CNF.
• Patent Document 1 states that “a nanofibrillated cellulose suspension is directly applied to and diffused on the surface of a plastic support material, whereby the nanofibrillated cellulose is deposited on the support material.
• this proposal does not examine the point (easy peeling) of peeling the obtained film from the support.
• the proposal also does not consider the point of making the appearance of the obtained film excellent, for example, the point that wrinkles or cracks do not exist.
• Patent Document 2 states that “(1) Cellulose microfibrils are 0.05% by weight or more and 0.5% by weight or less, and the boiling point range under atmospheric pressure is 50 ° C. or more and 200 ° C.
• the main problem to be solved by the present invention is to propose a method for producing a cellulose nanofiber film that can be easily peeled off from a substrate and has an excellent appearance, but does not complicate the production process. .
• Means for solving the above problems are as follows: One or more additives selected from glycerin, sorbitol, and polyvinylacetamide compounds are added to the dispersion of cellulose nanofibers to obtain a coating solution, Defoam this coating solution, apply it to a resin substrate, dry it into a film, This is a method for producing a cellulose nanofiber film.
• the cellulose nanofiber film can be easily peeled off from the substrate and has an excellent appearance, but the manufacturing process is not complicated.
• plant fibers for example, wood pulp made from hardwood, conifers, etc., non-wood pulp made from straw, bagasse, etc., recovered paper, waste paper pulp made from waste paper, etc. (DIP), etc. should be used. Can do. These plant fibers can be used alone or in combination.
• wood pulp for example, chemical pulp such as hardwood kraft pulp (LKP) and softwood kraft pulp (NKP), mechanical pulp (TMP), waste paper pulp (DIP) and the like can be used. These wood pulps can be used alone or in combination.
• LRP hardwood kraft pulp
• NBP softwood kraft pulp
• TMP mechanical pulp
• DIP waste paper pulp
• the hardwood kraft pulp may be hardwood bleached kraft pulp, hardwood unbleached kraft pulp, or hardwood semi-bleached kraft pulp.
• the softwood kraft pulp may be softwood bleached kraft pulp, softwood unbleached kraft pulp, or softwood semi-bleached kraft pulp.
• the waste paper pulp may be magazine waste paper pulp (MDIP), newspaper waste paper pulp (NDIP), corrugated waste paper pulp (WP), or other waste paper pulp.
• the raw fiber can be pretreated such as beating before defibration if necessary.
• This pretreatment can be performed by a physical method or a chemical method, preferably by a physical method or a chemical method. Pretreatment by physical or chemical methods prior to defibration can greatly reduce the number of defibrations and can greatly reduce the energy required for defibration.
• the beating can be performed using, for example, a refiner or a beater.
• Examples of the pretreatment using a chemical method include hydrolysis of a polysaccharide with an acid (acid treatment), hydrolysis of a polysaccharide with an enzyme (enzyme treatment), swelling of the polysaccharide with an alkali (alkali treatment), and oxidation of the polysaccharide with an oxidizing agent ( Oxidation treatment), polysaccharide reduction with a reducing agent (reduction treatment), and the like can be employed.
• the physical method and chemical method as the pretreatment can be performed simultaneously or separately.
• the raw fiber is subjected to pretreatment such as beating and then defibrated (miniaturized). By this defibration, the raw fiber is microfibrillated to become CNF (cellulose nanofiber).
• the high-pressure homogenizer is a homogenizer capable of discharging a dispersion of raw fiber at a pressure of, for example, 10 MPa or more, preferably 100 MPa or more.
• a high-pressure homogenizer capable of discharging a dispersion of raw fiber at a pressure of, for example, 10 MPa or more, preferably 100 MPa or more.
• the high-pressure homogenizer it is preferable to use a high-pressure homogenizer that collides the raw fiber dispersion in a straight line.
• a high-pressure homogenizer that collides the raw fiber dispersion in a straight line.
• an opposed collision type high-pressure homogenizer microwavefluidizer / MICROFLUIDIZER (registered trademark), wet jet mill.
• microfluidizer / MICROFLUIDIZER registered trademark
• wet jet mill two upstream flow paths are formed so that a pressurized dispersion of raw material fibers collides oppositely at the junction. Further, the raw material fiber dispersion collides at the junction, and the collided raw material fiber dispersion flows out of the downstream channel.
• the downstream flow path is provided perpendicular to the upstream flow path, and a T-shaped flow path is formed by the upstream flow path and the downstream flow path.
• the fibrillation of the raw fiber is such that the average fiber diameter, average fiber length, water retention, crystallinity, peak value of pseudo particle size distribution, and pulp viscosity of the obtained CNF are the desired values or evaluation as shown below. It is preferable to carry out. However, it is more preferable to defibrate until the raw fiber reaches a predetermined fiber diameter (average fiber diameter). By defibrating until the raw fiber reaches a predetermined fiber diameter, the water retention of CNF can be kept low. As a result, the coating property of the coating liquid can be improved.
• the average fiber length (length of single fiber) of CNF is, for example, 1 to 5000 ⁇ m, preferably 10 to 3000 ⁇ m, more preferably 100 to 1000 ⁇ m.
• the average fiber length of CNF can be adjusted by, for example, selection of raw fiber, pretreatment, defibration and the like.
• the method for measuring the average fiber length is the same as in the case of the average fiber diameter, and the length of each fiber is visually measured.
• the median length of the measured value is the average fiber length.
• the water retention of CNF is, for example, 300 to 500%, preferably 350 to 480%, more preferably 380 to 450%.
• the water retention of CNF can be adjusted by, for example, selection of raw fiber, pretreatment, defibration and the like.
• the water retention is determined by JAPAN TAPPI No. 26 (2000).
• the peak value in the pseudo particle size distribution curve of CNF is preferably one peak. When it is one peak, CNF has high uniformity of fiber length and fiber diameter, and is excellent in drying properties.
• the peak value of CNF is, for example, 5 to 25 ⁇ m, preferably 7 to 23 ⁇ m, more preferably 10 to 20 ⁇ m.
• the peak value of CNF can be adjusted by, for example, selection of raw fiber, pretreatment, defibration and the like.
• the peak value is a value measured according to ISO-13320 (2009). More specifically, first, the volume-based particle size distribution of the CNF aqueous dispersion is examined using a particle size distribution measuring device (laser diffraction / scattering type particle size distribution measuring instrument manufactured by Seishin Corporation). Next, the median diameter of CNF is measured from this distribution. This median diameter is the peak value.
• CNF dispersion CNF obtained by defibration is dispersed in an aqueous medium to form a dispersion.
• the total amount of the aqueous medium is particularly preferably water (aqueous solution).
• the aqueous medium may be another liquid partly compatible with water.
• other liquids for example, lower alcohols having 3 or less carbon atoms can be used.
• the B-type viscosity of the dispersion when the CNF concentration is 2% by mass (w / w) is preferably 3500 cps or less from the viewpoint of coating properties.
• the B-type viscosity is a value measured according to JIS-Z8803 (2011) “Method for measuring viscosity of liquid” for a CNF dispersion having a solid content concentration of 2.0 mass%.
• the B-type viscosity is a resistance torque when the dispersion is stirred, and the higher the viscosity, the more energy required for stirring.
• Glycerin Glycerin (glycerol) is a trivalent alcohol. Glycerin is obtained with a fatty acid by hydrolysis of fats and oils, for example. In the present specification, glycerol includes derivatives of glycerol.
• Addition of glycerin as an additive can impart flexibility to the CNF film, thus reducing shrinkage wrinkles and cracks during drying. (Good appearance can be obtained.)
• Sorbitol is a kind of sugar alcohol of glucose.
• sorbitol includes derivatives of sorbitol.
• the addition ratio of sorbitol is preferably 1.0 to 10.0% by mass, more preferably 2.0 to 10.0% by mass, and more preferably 3.0 to 10% with respect to the total amount of the coating liquid. It is particularly preferable that the content be 0.0 mass%. If the addition ratio is less than 1.0% by mass, the fluidity of the CNF aqueous solution may be deteriorated, resulting in difficulty in coating properties. (Poor appearance)
• the addition ratio of the polyvinyl acetamide compound is preferably 1.0 to 10.0% by mass, more preferably 2.0 to 10.0% by mass with respect to the total amount of the coating solution. It is particularly preferably 0 to 10.0% by mass.
• the addition ratio is less than 1.0% by mass, the compatibility with other additives is poor, and aggregates may be generated.
• the addition ratio exceeds 10.0% by mass, the shear stress of the CNF aqueous solution is excessively lowered, and there is a possibility that the film formation cannot be made uniform. (Appearance defect of CNF film)
• the coating solution obtained by adding various additives to the CNF dispersion preferably has a solid content concentration of 0.5 to 2.0 mass% from the viewpoint of coating properties.
• the B-type viscosity of the coating solution is preferably 500 to 3500 cps for the same reason.
• a method of adjusting the solid content concentration and B-type viscosity of the coating liquid to the above ranges a method of adding water to dilute when adding an additive, a method of adding other additives for adjusting viscosity, etc. Exists.
• the coating method of the coating liquid on the resin substrate may be a continuous method or a batch method.
• the continuous method for example, the coating liquid is continuously supplied to the coating apparatus, and the coating liquid is extruded thinly (in a thin layer) onto the resin base material by a discharging means such as a die attached to the coating apparatus.
• a discharging means such as a die attached to the coating apparatus.
• examples thereof include a method and a coating method using a roll coater, knife coater, roll knife coater, reverse coater, gravure coater and the like.
• the batch method include a method in which a coating liquid is cast on a resin substrate, and a thin layer is formed using an applicator, a Meyer bar, a knife coater, or the like.
• an additive was added to the CNF aqueous solution obtained as described above to obtain a coating solution.
• the types and amounts of additives are shown in Table 1. Further, the obtained coating liquid was stirred and defoamed using a stirring device (product name: KK-400W) manufactured by Kurashiki Boseki Co., Ltd.
• the defoamed coating solution was applied so that the thickness of the CNF film obtained on one surface of a PET resin substrate (product name: E5000, thickness 38 ⁇ m) was 10 ⁇ m.
• the present invention can be used as a method for producing a cellulose nanofiber film.

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Paper (AREA)
• Manufacture Of Macromolecular Shaped Articles (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Laminated Bodies (AREA)

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• 2017
  • 2017-03-16 JP JP2017051543A patent/JP6978843B2/ja active Active
• 2018
  • 2018-02-23 CN CN201880010635.6A patent/CN110268007A/zh active Pending
  • 2018-02-23 WO PCT/JP2018/006618 patent/WO2018168393A1/ja not_active Ceased
  • 2018-02-23 KR KR1020197025151A patent/KR20190126308A/ko not_active Ceased

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