JP2011202020A - Filler composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce energy used at production when producing a filler for a rubber or a resin, and to improve homogeneity and mixing stability.SOLUTION: A filler composition is produced by mixing dry natural pulp and dry powdered resin. The natural pulp is preferably paper pulp and is preferably natural pulp obtained by raveling printed waste paper e.g., newspaper, lightly coated paper, coated paper with high ash content, non-coated paper, etc. As the powdered resin, a polyolefin resin powder, a waste rubber powder, etc. can be used.

Description

  The present invention relates to a filler composition for a matrix material such as a resin or rubber, and more particularly to a filler composition excellent in admixture stability with a matrix resin or rubber.

  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

Although the bonding force between the fiber and the matrix has been improved by the method of Patent Document 5, the operation of removing a large amount of water from the aqueous slurry and energy are required, and the pulp slurry is squeezed to mix the fiber and the resin. When the composition is dried, lumps are formed, and problems remain in terms of uniformity and mixing stability.
An object of the present invention is to solve the above two problems. That is, it aims at reducing the use of energy during production and improving the uniformity and stability of mixing.

  The present inventors diligently studied means for adding natural pulp fibers to a matrix such as rubber or resin to improve mixing stability and improve strength and the like. As a result, a mixture of dry fiber and dry powder resin is used as a filler, and this is added to a resin such as polyethylene or rubber to improve the mixing stability, while maintaining strength, elasticity, and resistance. The present inventors have found that it is possible to improve the wearability and completed the present invention.

That is, the present invention is constituted by the following eight inventions (1) to (8).
(1) A filler composition obtained by mixing dry natural pulp and dry powder resin.
(2) The filler composition according to (1), wherein the dried natural pulp and the dried powder resin are mixed and the mixture is heated.
(3) The filler composition according to (1) or (2), wherein the dry powder resin is a polyolefin resin.
(4) The filler composition according to (1) or (2), wherein the powder resin in the dry state is a powdered rubber obtained by pulverizing a waste tire.
(5) The filler composition according to (1) or (2), wherein the dried natural pulp is a pulp for papermaking.
(6) The filler composition according to (5), wherein the papermaking pulp is at least one selected from chemical pulp, mechanical pulp, and used paper pulp.
(7) The natural pulp is at least one selected from plain white, card, special white, medium white, white Manila, imitation, color, cut, medium-finished, magazine, cardboard, and printed paper. The filler composition according to (6), characterized in that
(8) The filler composition according to (7), 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, it is possible to provide a filler composition excellent in strength, elasticity, and wear resistance while improving the mixing stability of the matrix and the filler. Moreover, the thermal energy in manufacture is reduced.

  The present invention is most typically a fiber composition obtained by mixing a dried waste paper pulp subjected to a defibrating treatment and a powdered polyolefin resin. More preferably, it is a fiber composition in which a mixture of used paper pulp and powdered polyolefin resin is heated to melt the powdered polyolefin resin and wet or adhere the surface of the used paper pulp fiber. The second representative example is a fiber composition obtained by mixing a waste paper pulp in a dried state subjected to a defibrating treatment and a powdered rubber resin. More preferably, it is a fiber composition in which a mixture of used paper pulp and powdered rubber resin is heated to melt the rubber resin and wet or adhere the used paper pulp fiber surface. Below, the case where mainly used paper pulp and powdered resin are utilized is demonstrated as an example.

Conventionally, waste paper pulp and rubber, resin, and the like have been heat-kneaded with a kneader equipped with a rotary mixer. A shear was applied in the gap between the rotary mixer blade and the inner wall of the kneader to knead the molten resin and waste paper pulp. However, the shear in the kneader is not uniform, and the shear is less likely to be applied as the distance from the rotating mixer blades increases. Accordingly, the vicinity of the inner wall of the kneading machine was not sheared, the cohesive force between the used paper pulp fibers became dominant, and the used paper pulp fibers were likely to be agglomerated.
In order to prevent this, the present inventor considered that an environment in which the resin is present is necessary in the vicinity of the used paper pulp, and considered that mixing the used paper pulp and the powdered resin led to the present invention.
Generally, the surface of natural pulp is fibrillated. Fibrilization is a state in which the surface of the pulp fiber is fuzzed, and this strengthens the bond between the pulp fibers. By encapsulating a powdery resin in the fluff portion on the surface, an environment in which the resin always exists in the vicinity of the waste paper pulp can be given.

  Examples of the used paper used in the present invention include those known in the art, such as used newspaper, corrugated cardboard, magazine used paper, etc. discharged from homes, factories, business establishments and the like. 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. There is a risk of causing.
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.

Various powdery resins are used as the powdery resin used in the present invention. In particular, from the viewpoint of cost, polyolefin-based powdered resins and powdered rubber resins obtained from waste tires are preferably used. Furthermore, a resin for toner is preferably used.
The selection of the powder resin to be mixed with the dry fibers is preferably determined depending on what matrix resin is filled with the filler composition prepared in the present invention. For example, when filling the polyolefin resin with the filler composition of the present invention, it is preferable to select a polyolefin-based powder resin as the powder resin mixed with the dry fiber. When the acrylic resin is filled with the filler composition of the present invention, an acrylic powder resin is preferably selected as the powder resin to be mixed with the dry fiber. In addition, when the rubber-based resin is filled with the filler composition of the present invention, it is preferable to select a powder rubber resin as the resin mixed with the dry fiber. The powder resin to be mixed is preferably determined depending on which matrix resin is filled with the filler composition of the present invention.

Various resin powders can be used as the powder resin. For example, polyolefin resin, acrylic resin, methacrylic resin, urethane resin, nylon resin, various vinyl resins, epoxy resin, novolac resin, polyester resin, various rubbers, etc. A bead-like material synthesized by polymerization can also be used. Specifically, various commercially available resin powders can be used. Polyolefin powder resin includes polyethylene powder resin (trade name: Flocene, manufactured by Sumitomo Seika), polypropylene powder resin (trade name: Flowprene, manufactured by Sumitomo Seika), ethylene vinyl acetate powder resin (trade name: Flowback, Sumitomo Seika) ). Specific products of waste tire powder resin include P-83, P-100, P-160 (made by Shinsei Rubber Co., Ltd.).
When pulverizing wastes such as plastics and tires, they may be crushed into fine fibers or flakes, but these are also included in the powder in this specification.

  The particle size of the powder resin to be used is not particularly limited, but the average particle size is about 10 μm to 1 mm, preferably about 100 μm to 500 μm. Incidentally, if the average particle diameter is less than 10 μm, a problem occurs in workability. When the average particle diameter is 1 mm or more, it is difficult to encapsulate the fiber surface fibril part.

The mixing ratio of the natural pulp and the powder resin is preferably 5 to 100 parts by mass, preferably 10 to 70 parts by mass with respect to 100 parts by mass of the natural pulp. When the blending amount of the powder resin is less than 5 parts by mass, when the filler composition is added to the matrix and mixed, the miscibility becomes insufficient, and the strength, elasticity, and wear resistance may be insufficient. When the amount of the powder resin exceeds 100 parts by mass, the miscibility with the matrix resin or the like is not further improved. As a result, the cost may increase.

  A known method can be used to mix the dried natural pulp and the powdered resin. Any method and apparatus can be used as long as the natural pulp and the powder resin can be mixed uniformly. Specifically, a method of mixing by hand many times, a method of mixing for a certain time using a vibration device, a method of blowing natural pulp and powdered resin separately with air and colliding them in the air can be used.

The mixed natural pulp and powder resin may be bulky and difficult to handle. In this case, it is better to heat the mixture and dissolve the powder resin to wet the natural pulp surface, or to make it adhere to reduce the bulk. As a heating method, for example, known methods such as hot air drying, heating using a dry kiln, infrared heating, etc. can be used alone or in combination. Among them, hot press heating such as iron is effective because it can reduce the bulk, but it is necessary to pay attention to the fact that the powder resin only on the surface dissolves and the powder resin existing inside does not dissolve.
In any case, it is preferable that a part or all of the powder resin is melted and adhered to the pulp.

The matrix resin to which the filler composition of the present invention is added includes various rubbers, polyolefin resins, acrylic resins, methacrylic resins, urethane resins, nylon resins, various vinyl resins, epoxy resins, novolac resins, polyesters, etc. Various condensed 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.

  As described above, the filler composition of the present invention is extremely excellent in miscibility with rubber, elastomer, and other resins which are matrices because the resin is combined with the waste paper pulp fiber. For this reason, the composition in which the filler is blended in the matrix is in a uniform mixed state, and cracks are hardly generated even in the strength test of the composition. 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% are mass%.

Example 1
Waste paper with a moisture content of 6% by mass was crushed using a pulp crusher (trade name: “FR-160”, manufactured by Ruikou Iron Works Co., Ltd.), and then a pulp crusher (trade name: “P-270”, Zuikou Ironworks Co., Ltd.). Was used to obtain a waste paper pulp fiber. The length-weighted average fiber length of the obtained waste paper pulp fiber was 1.20 mm. 100 parts by mass of this used paper pulp and 15 parts by mass of powdered medium density polyethylene (reagent, manufactured by Aldrich) were sufficiently mixed by hand to obtain a filler composition.
20 parts of the obtained filler composition was filled into a mixture of 55 parts of low density polyethylene (reagent, manufactured by Aldrich) and 25 parts of maleic acid-modified polyethylene (reagent, manufactured by Aldrich), and Laboplast mill (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.
The produced plate-like sample was visually observed to observe the aggregated state and aggregated state of the fibers. The results are shown in Table 1.

(Example 2)
The same operation as in Example 1 was performed. However, the obtained filler composition was heat-treated with an iron to form a blanket. The blanket-like filler composition was crushed into small pieces to obtain the final filler composition.
Observation of a cross-sectional photograph of the small piece revealed that the surface of the powder melted and adhered to the pulp.

(Example 3)
The same operation as in Example 1 was performed. However, powdered rubber (trade name: P-83, manufactured by Shinsei Rubber Co., Ltd.) was used instead of the medium density polyethylene.

Example 4
The same operation as in Example 1 was performed. However, powdered polystyrene (reagent, manufactured by Aldrich) was used in place of powdered medium density polyethylene.

(Example 5)
The same operation as in Example 1 was performed. However, powdered paraffin wax (trademark: SP0145, manufactured by Nippon Wax) was used in place of powdered medium density polyethylene.

(Example 6)
The same operation as in Example 1 was performed. However, dry pulp described below was used instead of waste paper pulp.
Kraft pulp with a moisture content of 50% by mass was crushed using a pulp crusher (trade name: “FR-160”, manufactured by Ruikou Iron Works Co., Ltd.), and then a pulp crusher (trade name: “P-270”, Suikou Iron Works, Inc.). And then dried to obtain pulp fibers. The length weighted average fiber length of the obtained pulp fiber was 1.60 mm.

(Example 7)
The same operation as in Example 1 was performed to obtain a filler composition. 20 parts of the obtained filler composition was filled in 80 parts of a polylactic acid resin (trademark: TE2000, manufactured by Unitika) 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.
The produced plate-like sample was visually observed to observe the aggregated state and aggregated state of the fibers. The results are shown in Table 1.

(Comparative Example 1)
The same operation as in Example 1 was performed. However, powder medium density polyethylene was not used.

(Comparative Example 2)
Example 7 The same operation was performed. However, powder medium density polyethylene was not used.

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

  The filler composition of the present invention is lightweight and excellent in mixing stability with a matrix rubber, elastomer, resin and the like, and can improve properties such as strength, elasticity, and abrasion resistance. The composition has extremely excellent characteristics.

Claims (8)

A filler composition comprising a dried natural pulp and a dried powdered resin. The filler composition according to claim 1, wherein the natural pulp in a dry state and a powder resin in a dry state are mixed and the mixture is heated. The filler composition according to claim 1, wherein the dry powder resin is a polyolefin-based resin. The filler composition according to claim 1, wherein the dry powder resin is a powdered rubber obtained by pulverizing a waste tire. The filler composition according to claim 1 or 2, wherein the dried natural pulp is paper pulp. The filler composition according to claim 5, wherein the papermaking pulp is at least one selected from chemical pulp, mechanical pulp, and used paper pulp. The natural pulp is at least one selected from upper white, card, extra white, middle white, white manila, imitation, color, cutting, middle and old, magazine, cardboard, and printed paper. The filler composition according to claim 6. 8. The filler composition according to claim 7, wherein the used printed paper is at least one selected from newspaper, fine coated paper, high ash coated paper, and non-coated paper.