JP2011246615A - Method of manufacturing fiber composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method which can improve a mixing property to rubber and resin by mixing an additive to a fiber, and can uniformly mix the fiber and the additive, when manufacturing a vegetable fiber filler to be filled to the rubber and the resin.SOLUTION: The method mixes the additive which can improve the mixing property to a matrix material such as the resin, the rubber or the like to the vegetable fiber. The dry fiber is stirred in a closed chamber by a first blade arranged at the bottom of the chamber, the additive in a fine droplet state is added to the fiber while stirring the fiber by a second blade arranged at the side of the chamber, and the stirring is continued. A fine droplet is a solution or a dispersion liquid of a lubricant, and it is preferable to spray the fine droplet. The vegetable fiber is formed by fibrillating waste paper, and the waste paper is selected from newspaper, lightly coated paper, high-ash content enamel paper, non-enamel paper or the like.

Description

  The present invention relates to a method for producing a fiber composite material suitable as a filler for a matrix material such as a resin or rubber, and more particularly, an additive for improving the miscibility of plant fibers with a matrix resin or rubber. The present invention relates to a method of mixing an agent with plant fibers.

  As a method for reinforcing rubber or resin, a method in which organic fibers or inorganic fibers are cut short and mixed with rubber or resin as a matrix is known. By blending short fibers, the elastic modulus and tear strength of rubber can be improved, and the amount of rubber used in rubber products such as tires, belts and hoses can be reduced, which is effective for resource saving and weight reduction. However, fiber materials blended with these fibers are usually used in which fibers spun newly spun for reinforcing short fibers are cut by a fiber maker, and are expensive (Patent Document 1). ).

  In addition, there is also known one that uses waste paper or waste paper pulp as a reinforcing material (Patent Documents 2 to 4), but the cellulose fibers are not sufficiently dispersed in the rubber, and the effect of improving properties such as strength is also achieved. It was insufficient.

Adding and mixing plant fibers as fillers is effective to change the viscosity characteristics of the matrix rubber, elastomer, resin, etc., to provide stability, and to supplement the strength by creating a structure between the matrices. It is. In addition, the use of waste paper as an inexpensive plant fiber is in line with the orientation of recycling and reuse in terms of the environment.
However, even if plant fibers are simply added to the resin and kneaded, the cohesive force between the fibers is stronger than the intermolecular force between the fibers and the resin, so that the fiber mass remains after kneading. The physical properties were adversely affected.

  In order to strengthen the bond between the fiber and the resin, the present applicant has proposed a method of adding latex to an aqueous slurry obtained by disaggregating used paper pulp in Patent Document 5.

JP-A-9-12770 Japanese Patent Laid-Open No. 62-104851 JP 2002-37929 A Japanese Patent Laid-Open No. 11-217466 JP 2009-91388 A

According to the method of Patent Document 5, the bonding force between the fibers and the matrix has been improved. However, the operation and energy for removing a large amount of water from the aquatic slurry are required, and the pulp slurry is squeezed to mix the fibers and the resin. When the composition is dried, lumps are formed, and problems remain in terms of uniformity and mixing stability.
In this regard, the present inventors previously proposed a method of simultaneously spraying latex and disused waste paper pulp in Japanese Patent Application No. 2010-030054. However, this method is easy to apply to things such as latex binders that have the ability to adhere pulp, but it may be difficult to apply to those that do not adhere to pulp, and it can improve uniformity and improve continuous productivity. There was also an aspect that it was difficult to improve in terms of improvement.
Therefore, the present invention is applicable to any of various additives that improve the miscibility of pulp with a matrix such as rubber or resin, and further improves the uniform mixing property of the additive to the plant fiber. To do.

  The inventors of the present invention have completed the present invention as a result of earnestly examining means for uniformly blending additives for improving miscibility when mixing dry plant fibers into a matrix such as rubber or resin. I let you.

That is, the present invention is constituted by the following five inventions (1) to (5).
(1) A method of mixing an additive for improving the miscibility with a matrix material such as a resin or rubber with a plant fiber, wherein the first fiber provided at the bottom of the fiber in a dry state in a sealed chamber A method for producing a fiber composite material, characterized by adding an additive in the form of a fine droplet while stirring with a second blade provided on the side at the same time as stirring, and further continuing stirring.
(2) The method for producing a fiber composite material according to (1), wherein the minute liquid enemy is a solution or dispersion of a lubricant.
(3) The method for producing a fiber composite material according to (1) or (2), wherein the plant fibers are fibers obtained by defibrating waste paper.
(4) The used paper is at least one selected from upper white, card, white, middle white, white manila, imitation, color, cutting, middle and old, magazine, cardboard, and printed old paper. The manufacturing method of the fiber composite material as described in (3).
(5) The method for producing a fiber composite material according to (4), wherein the used printed paper is at least one selected from newspaper, fine coated paper, high ash coated paper, and non-coated paper. .

  According to the present invention, when various additives that improve the miscibility between plant fibers and a matrix such as rubber or resin are mixed with the plant fibers, the uniform mixing of the additives with the plant fibers can be improved.

  The present invention is a method for producing a fiber composite material, characterized in that a liquid additive is supplied to and contacted with dried plant fibers that are stirred and dispersed in air, and further dried as necessary. is there.

As the plant fiber used in the present invention, waste paper is most preferable from the viewpoint of economical efficiency and availability. Hereinafter, the case where waste paper is mainly used will be described as an example.
Examples of the used paper include those known in the art such as newspaper used paper, corrugated cardboard paper, magazine used paper, and the like discharged from homes, factories, and business establishments. Specifically, used newspapers, books, magazines, phone books, catalogs, high-quality paper, packaging boxes, cardboard boxes, white-white, cards, white, medium white, white Manila, imitation, color, cut Appendices, middle and old garments, pulp molds, paper cushioning materials, papermaking, printing, bookbinding, box making, cuts and waste paper discharged from factories and business offices such as corrugated board manufacturing. Of these, used printing paper such as newspaper, finely coated paper, high ash coated paper, and non-coated paper is preferable.

  In the present invention, waste paper is first defibrated. For the treatment, it is preferable to use a dried waste paper having a moisture content of 20% or less. The treatment may be performed in a wet state, but a treatment in a dry state with a low possibility of mixing in foreign matters is preferable.

  Examples of devices used for defibration include grinders such as pocket grinders, chain grinders, ring grinders, refiners such as single disc refiners, double disc refiners, conical refiners, and other beating machines such as beaters, blenders, and deflakers. Etc., wood chip defibrators such as defibrators and defibrizers, and other flash dry pulp production facilities such as fluffers. Among these, an apparatus equipped with a mechanism capable of forcibly supplying raw materials such as a pressurization method and a screw method is preferable because defibration can be performed continuously and efficiently. These are generally of various types such as a device for treating wet fibers and a device for treating dry fibers, but can be used as a defibrating treatment device as long as they can be used regardless of moisture. However, dry defibration that does not use water at all or uses a small amount of water is preferable in terms of easy drainage treatment. In the case of the wet method, defibration in a state where the solid content concentration is high is more preferable in that the defibrating efficiency and the load of the subsequent dehydration drying process can be suppressed.

The defibrated waste paper pulp fiber used in the present invention is not particularly limited with respect to the fiber width, but the average fiber length is 0.1 to 5.0 mm, preferably about 0.3 to 1.5 mm. . Incidentally, if the average fiber length of the waste paper pulp fiber is less than 0.1 mm, a great deal of energy is required for defibration, and the entanglement with the matrix resin or the like may be reduced, and the strength of the material as the final product may be reduced. is there. In addition, when the average fiber length exceeds 5.0 mm, the entanglement between the fibers becomes too strong, and the fibers are aggregated. As a result, the dispersibility with respect to the matrix resin or the like is inferior, and as a result, the strength of the material that is the final product is reduced. There is a risk of it coming.
In order to fibrillate the defibrated waste paper pulp fiber, it is necessary to rub the used paper pulp in the defibrating apparatus. Even with the same fiber length, the entanglement between the fibers that have been defibrated with or without fibrillation differs. When fibrillated, it becomes cottony. The equipment conditions need to be adjusted to be optimized.

  The waste paper-derived pulp fiber is preferably newspaper waste paper as used paper. When using old newspaper, the average fiber length is likely to fall within the range of 0.1 to 5.0 mm, and the mechanical pulp blended at the time of newsprinting has an alkyl group on the pulp surface, so it tends to be hydrophobic. For this reason, it has the advantage that it can be easily dispersed in rubber, resin, or the like serving as a matrix.

The additive used in the present invention may be used as it is if it is liquid at room temperature (25 ° C.), or may be supplied as a solution or dispersion of the additive. By using water as a solvent or dispersion medium for the additive, a large number of droplets are formed when sprayed in the air, and the additive is uniformly supplied and adhered to the pulp fiber.
Examples of the additive include an adhesive, a liquid polymer, and a lubricant.

  An example of the adhesive is a resin emulsion. Examples of the resin emulsion and latex include natural rubber, modified natural rubber, styrene-isoprene copolymer, styrene-butadiene copolymer, carboxy-modified styrene-butadiene copolymer, carboxy-modified styrene-methyl methacrylate-butadiene copolymer, Carboxy-modified styrene-acrylonitrile-butadiene copolymer, carboxy-modified styrene-methyl methacrylate-acrylonitrile-butadiene copolymer, acrylonitrile-butadiene copolymer, methyl methacrylate-butadiene copolymer, carboxy-modified methyl methacrylate-butadiene copolymer, Styrene-butadiene-2-vinylpyridine copolymer, polyvinyl acetate, ethylene-vinyl acetate copolymer, (meth) acrylic acid ester homopolymer, (meth) acrylate Luric acid ester copolymer, ethylene-vinyl acetate / acrylic acid ester composite resin, polyethylene wax, low density polyethylene, vinyl chloride resin, vinylidene chloride resin, acrylic resin, polyester resin, nylon resin, amide Examples of the resin include urethane resin, urethane resin, and vinyl urethane resin.

  Liquid rubber includes liquid polyisoprene rubber, liquid polybutadiene rubber, liquid natural rubber, liquid butadiene-isoprene rubber, liquid styrene-isoprene rubber, liquid styrene-butadiene rubber, liquid acrylonitrile-butadiene rubber, liquid polychloroprene and hydrogenation thereof. Products, liquid silicone rubber, liquid polysulfide rubber, liquid fluororubber, liquid polyisobutylene and the like.

  Specific examples of the lubricant include hydrocarbon lubricants such as paraffin and wax, fatty acid lubricants such as higher fatty acids and oxy fatty acids, fatty acid amide lubricants such as fatty acid amides and alkylene bis fatty acid amides, fatty acid lower alcohol esters, Examples thereof include ester lubricants such as monohydric alcohol esters and fatty acid polyglycol esters, alcohol lubricants such as fatty alcohols, polyhydric alcohols, polyglycols and polyglycerols, metal soaps, and mixed lubricants. These lubricants may be naturally derived or synthetic, and can be used alone or in combination of two or more. Further, solubilizers, dispersants and emulsifiers may be used in combination in order to make the lubricant into a solution or dispersion.

In the method of the present invention, the dried fiber is stirred with the first blade provided at the bottom in the sealed chamber, and at the same time, the additive in the microdroplet state is added with the second blade provided at the side. It is characterized in that it is added and stirring is continued. If the additive is supplied at once as a solid state or a liquid, it is difficult to sufficiently uniformly mix the plant fiber.
Moreover, since mixing cannot be performed uniformly only by stirring a plant fiber by a normal mixer, two stirring blades are used. The first blade provided at the bottom of the apparatus mainly has a function of greatly stirring the whole plant fiber and simultaneously dispersing it in the air. About 2 to 5 normal blades may be used. The second blade provided on the side of the device is necessary to cause turbulence to the plant fiber dispersed in the air by the first blade and to retain it for a long time in a state dispersed in the air. is there.

The additive is added as fine droplets. As a method for forming fine droplets, either a shower method in which liquid is supplied from a minute hole or a spray method in which droplets are formed by gas may be used. Commercial atomizers can be used.
When the additive itself is a liquid component containing no solvent, it can be used immediately after stirring. However, when the additive is used as a solvent solution or dispersion, it must be dried after stirring. Drying may be performed by standing, but is preferably performed while stirring with hot air.

  The blending ratio of the fiber and the additive is preferably 0.5 to 75 parts by mass, more preferably 1 to 50 parts by mass, with 100 parts by mass of the fiber as the solid content of the additive. When the compounding amount of the additive is less than 0.5 parts by mass, the composite material may be insufficiently dispersed when the composite material is added to and mixed with the matrix. If the solid content of the additive exceeds 75 parts by mass, the quality may be impaired due to a phenomenon such as bloom or bleeding where the additive appears on the surface of the matrix and the composite material.

  As the matrix resin to which the composite material of the present invention is added, various condensations such as various rubbers, polyolefin resins, acrylic resins, methacrylic resins, urethane resins, nylon resins, various vinyl resins, epoxy resins, novolac resins, polyesters, etc. Series resins can be used. From the environmental point of view, it is preferable to use a biodegradable resin such as polylactic acid.

  Specifically, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-vinyl chloride copolymer, ethylene-vinyl alcohol copolymer, chlorinated polyethylene, maleic anhydride-modified polyethylene, polyacetal, polyamide, polyamideimide, polyarylate, polyethylene terephthalate, poly Examples include vinylidene chloride, polyvinyl chloride, polycarbonate, polystyrene, polysulfone, polyvinyl alcohol, polyvinyl ether, polyvinyl butyral, polyacrylate, polymethyl methacrylate, polyurethane, carboxymethyl cellulose, and polyterpene.

  The composite material of the present invention is extremely excellent in dispersibility with respect to rubber, elastomer, and other resins as a matrix since the additive is combined with the craft fiber such as waste paper pulp as described above. For this reason, the composition in which the composite material is blended in the matrix is in a uniform mixed state, and cracks are hardly generated even in the strength test of the composition, which is considered to exhibit excellent characteristics. Similarly, it is considered that elasticity and wear resistance are also improved.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the following examples, all parts are parts by mass.

(Creation of waste paper pulp fiber A)
Using a pulp crusher (trade name: P-270, manufactured by Zuikou Iron Works Co., Ltd.) after crushing old newspaper with a moisture content of 6% by mass using a pulp crusher (trade name: FR-160, manufactured by Ruikou Iron Works Co., Ltd.) Then, the fiber was defibrated by a dry method to obtain waste paper pulp fiber A. The length-weighted average fiber length of the obtained waste paper pulp fiber A was 1.20 mm.

Example 1
Place 100 parts of waste paper pulp fiber A in a container with a propeller on the bottom and side, and stir and disperse the waste paper pulp fiber A by high-speed rotation of the propeller. : Chemipearl W-401, solid content concentration 40%, manufactured by Mitsui Chemicals Co., Ltd.) 30 parts (12 parts as solid content) was sprayed at a feed rate of about 50 grams per minute, and then heated at 80 ° C. using a hot air dryer. The composite material A was obtained by drying for 1 hour.

  15 parts of the obtained composite material A was filled into a mixture of 60 parts of low-density polyethylene (reagent, manufactured by Aldrich) and 25 parts of maleic acid-modified polyethylene (reagent, manufactured by Aldrich), and a lab plast mill (manufactured by Toyo Seiki). Kneaded. The kneading temperature is 180 ° C. and the kneading time is 10 minutes. The obtained kneaded material was press-molded at 160 ° C. to prepare a plate sample.

(Example 2)
Low molecular weight polyethylene dispersion (trade name: Chemipearl W-401, solid content concentration 40%, manufactured by Mitsui Chemicals) zinc stearate emulsion (trade name: Himicron F-930, solid content concentration 40%, manufactured by Chukyo Yushi Co., Ltd.) The composite material B was obtained in the same manner as in Example 1 except that the above was changed.

  A plate-like sample was prepared in the same manner as in Example 1 except that the composite material A was changed to the composite material B.

(Comparative Example 1)
15 parts of waste paper pulp fiber A was filled in a mixture of 60 parts of low density polyethylene (reagent, manufactured by Aldrich) and 25 parts of maleic acid-modified polyethylene (reagent, manufactured by Aldrich), and kneaded with a lab plast mill (manufactured by Toyo Seiki). . The kneading temperature is 180 ° C. and the kneading time is 10 minutes. The obtained kneaded material was press-molded at 160 ° C. to prepare a plate sample.

(Comparative Example 2)
Waste paper pulp fiber A 100 parts and low molecular weight polyethylene dispersion (trade name: Chemipearl W-401, solid content concentration 40%, manufactured by Mitsui Chemicals) 30 parts (12 parts as solid content) with propeller only at the bottom After putting into a container and stirring by high-speed rotation of a propeller, the composite material D was obtained by drying at 80 ° C. for 1 hour using a hot air dryer.

  A plate-like sample was prepared in the same manner as in Example 1 except that the composite material A was changed to the composite material D.

<Evaluation method>
The obtained Examples and Comparative Examples were evaluated for dispersibility (fiber aggregation state and aggregation state) according to the following evaluation criteria, and are shown in Table 1.

(Dispersibility)
The fiber dispersion state of the obtained plate-like sample was visually evaluated.
○: Dispersed uniformly, and aggregates of fibers are not seen.
Δ: Slightly aggregated fibers.
X: An aggregate of fibers is seen.

  As is apparent from Table 1, the composite material obtained by the method of the present invention is extremely excellent in dispersibility with a matrix such as a resin.

  The composite material obtained by the method of the present invention is lightweight and has excellent dispersibility in a matrix rubber, elastomer, resin and the like, and can improve properties such as strength, elasticity, and abrasion resistance. It has extremely excellent characteristics as a composite material.

Claims (5)

A method of mixing an additive for improving the miscibility with a matrix material such as a resin or rubber with a plant fiber, and simultaneously stirring the dried fiber with a first blade provided at the bottom in a sealed chamber A method for producing a fiber composite material, comprising adding an additive in the form of a fine droplet while stirring with a second blade provided on the side, and further continuing stirring. The method for producing a fiber composite material according to claim 1, wherein the minute liquid enemy is a solution or dispersion of a lubricant. The method for producing a fiber composite material according to claim 1, wherein the plant fiber is a fiber obtained by defibrating waste paper. The waste paper is at least one selected from upper white, card, extra white, middle white, white Manila, imitation, color, cut, intermediate, old, magazine, cardboard, and used printed paper. Item 4. A method for producing a fiber composite material according to Item 3. The method for producing a fiber composite material according to claim 4, wherein the used printed paper is at least one selected from newspaper, fine coated paper, high ash coated paper, and non-coated paper.