Masterbatch manufacturing method and resin masterbatch manufacturing method

Abstract

To provide a method for producing resin masterbatch that suppresses resin foaming and enables normal resin granulation, and to provide a method for producing resin masterbatch.MEANS FOR SOLVING THE PROBLEM: The method for producing resin masterbatch includes the steps of: mixing / kneading a plurality of additives in which at least one is hydrous, and solidifying to yield a solid material composed of the plurality of additives; dehydrating the solid material; melting and / or pressure granulating the dehydrated solid material to yield a masterbatch; and mixing a resin with the masterbatch and performing melt granulation to yield a resin masterbatch.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a method for producing a masterbatch and a method for producing a resin masterbatch. [Background technology]

[0002] The use of masterbatches has the advantage that there is no need to worry about scattering within the factory or contamination of machinery compared to using powder materials, it is safe to handle, and leads to more efficient work.

[0003] Meanwhile, in the plastics industry, wood flour has been widely combined with resins such as polyvinyl chloride and polypropylene. Wood flour is used to give molded products a texture similar to that of wood materials, and also as a bulking agent.

[0004] In order to mix wood flour uniformly into resin, the wood flour is crushed as much as possible and used so that it passes through a fine mesh. If wood chips or wood fibers before crushing are used, it is difficult to incorporate the desired amount due to their large volume, and it is also difficult to feed them quantitatively into a continuous mixer, so wood flour is used for mass production.

[0005] However, since fine wood powder causes problems such as scattering and contamination of machinery, it has been devised to be used by making it into a masterbatch as described above (Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-119559 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the above-mentioned wood flour masterbatch is used and mixed with a resin, the resin foams, preventing normal granulation.

[0008] In view of the above problems, an object of the present invention is to provide a method for producing a masterbatch and a method for producing a resin masterbatch that suppress resin foaming and enable normal resin granulation. [Means for solving the problem]

[0009] As a result of intensive research into solving the above-mentioned problems, the present inventors have found that foaming that occurs when a masterbatch of wood flour or the like is mixed with a resin and granulated is caused by moisture contained in the masterbatch, and have thus come up with the following invention.

[0010] That is, the present invention is as follows. [1] A step of mixing and kneading a plurality of additives, at least one of which is water-containing, to solidify the additives, thereby obtaining a solid material comprising the plurality of additives; dewatering the solid material; a step of melting or pressure granulating the dehydrated solid material to obtain a masterbatch; wherein the dehydration is carried out by contacting the solid with a hygroscopic liquid or a polymeric adsorbent. [2] A step of mixing and kneading a plurality of additives, at least one of which is water-containing, to solidify the additives, thereby obtaining a solid material comprising the plurality of additives; dewatering the solid material; a step of melting or pressure granulating the dehydrated solid material to obtain a masterbatch; a step of mixing the masterbatch with a resin and melt-granulating the mixture to obtain a resin masterbatch; wherein the dehydration is carried out by bringing the solid into contact with a hygroscopic liquid or a polymer adsorbent. [3] The method for producing a masterbatch according to [1] or the method for producing a resin masterbatch according to [2], wherein the dehydration is carried out by subjecting the solid to at least one method selected from the group consisting of natural drying, hot air drying, freezing, and electromagnetic induction heating.

[0011] The term "water-containing" is a concept that includes not only the case where the additive itself originally contains water, but also the case where water is added to the additive later, such as an additive such as bentonite that is dissolved in water before use. [Effects of the Invention]

[0012] As described above, according to the present invention, the solid material used as the masterbatch is dehydrated before it is obtained, which allows the water content in the masterbatch to be sufficiently reduced and prevents foaming when mixed with a resin.

[0013] Furthermore, even when an additive has poor thermal melting properties, such an additive is made into a masterbatch in advance, and then mixed with a resin and melt-granulated, so that the additive can be uniformly dispersed in the resin (masterbatch).

[0014] Furthermore, since the masterbatch contains multiple additives, the multiple additives can be dispersed uniformly in the resin without scattering within the factory or contaminating machinery, as is the case when powder materials are used. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a process diagram showing a manufacturing process of a masterbatch and a resin masterbatch according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, details and other features of the present invention will be described based on embodiments.

[0017] (Additive preparation process: S1) First, in this embodiment, a plurality of additives that are raw materials for the masterbatch are prepared. From the viewpoint of suppressing foaming due to moisture through a dehydration process as described below, at least one of the additives contains moisture and / or is hydrated, such as bentonite, and thus has a hydrous property.

[0018] Examples of such additives include plant fibers such as linen, cotton, ramie, and polynosic; animal hair such as silk obtained from cocoons; clay minerals such as bentonite, kaolinite, montmorillonite, talc, and zeolite; waste paper, recycled paper, and factory waste paper; starches such as potato, corn starch, and tapioca; biodegradable resins such as polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT); wood vinegar; and various pesticides. Other examples include photocatalysts such as titanium oxide; vegetable oils and fats such as carboxycellulose (CMC), poval, corn oil, and palm oil; and calcium-containing substances such as eggshells and baked shellfish.

[0019] By using fibers and clay minerals as additives, the mechanical strength (tensile strength, bending strength, breaking strength, impact resistance, etc.) of the final resin molded product can be improved. Furthermore, by using photocatalysts, resin molded products can have gas adsorption and decomposition functions. Furthermore, by using vegetable oils and fats, the compatibility between hydrophilic additives and hydrophobic materials, i.e., resin, can be improved.

[0020] 1 shows three types of additives, A, B, and C, but any of the additives may be the water-containing additives described above. All of A, B, and C may be water-containing additives, or one or two of A, B, and C may be water-containing additives.

[0021] Furthermore, although three types of additives, A, B, and C, are listed in FIG. 1, two types, A and B, or four or more types, A, B, C, D, etc., may be used.

[0022] Furthermore, at least one of the additives used in this embodiment may be a water-containing additive as described above, or may be a general-purpose additive, such as a plasticizer, antioxidant, ultraviolet absorber, weathering agent, heat stabilizer, antiblocking agent, antistatic agent, lubricant, flame retardant, neutralizing agent, waterproofing agent, water repellent, or antibacterial agent.

[0023] By using a waterproofing agent, a water-repellent agent, or an antibacterial agent as an additive, it is possible to impart waterproofing, water-repellent, antibacterial properties, etc. to the final resin molded product.

[0024] (Mixing and kneading / solidification process: S2) Next, in this embodiment, the plurality of additives prepared in step S1 are put into a kneader and kneaded to produce a solid material.

[0025] As the mixer, a general-purpose mixer such as a W-type mixer, a V-type mixer, a drum-type mixer, or a ribbon-type mixer can be used.

[0026] The kneading is continued until the above-mentioned plurality of additives are solidified, for example, for 5 to 30 minutes.

[0027] The solid matter L1 obtained in this step is an agglomerate of the above-mentioned multiple additives, and its size is, for example, 0.5 mm to 15 mm in diameter and 1 mm to 15 mm in length.

[0028] (Dehydration process: S3) Next, in this embodiment, the solid material L1 obtained as described above is subjected to dehydration.

[0029] The dehydration operation is not particularly limited, and can be carried out, for example, by bringing a hygroscopic liquid into contact with the solid L1. Examples of the hygroscopic liquid that can be used include solutions of deliquescent salts such as lithium chloride and saline, highly hygroscopic polyhydric alcohols such as glycerin, ethylene glycol, and propylene glycol, and other inexpensive hygroscopic liquids.

[0030] The dehydration time depends on the amount of water contained in the solid L1, the concentration of the hygroscopic liquid, and the like, but is, for example, 10 to 120 minutes.

[0031] Dehydration using a hygroscopic liquid can be carried out at 1.5 atmospheres and room temperature.

[0032] Instead of the hygroscopic liquid, a solid polymer adsorbent may be used. Commercially available polymer adsorbents may be used.

[0033] Alternatively, the dehydration process can be carried out by electromagnetic induction heating. Specifically, electromagnetic waves (microwaves) are applied to a solid object placed in a designated container to heat and evaporate the water. The time required for dehydration depends on conditions such as the strength of the applied electromagnetic waves (microwaves), but is usually only a few minutes.

[0034] Alternatively, dehydration can be performed by a normal heating operation using hot air from a heater. In this case, the hot air temperature is, for example, 30 to 100°C.

[0035] It can also be achieved using freezing techniques such as freeze-drying.

[0036] Furthermore, dehydration can also be achieved by natural drying without performing the above-mentioned active operation.

[0037] Furthermore, the solid material can be placed in a hopper, and then introduced from the hopper into a tube such as a cylinder wound with an electric heating coil, and electricity is then applied to the coil to dehydrate the solid material by the heat generated by the current. In this case, the heating temperature is, for example, 30 to 150°C, and the heating time is 30 to 180 minutes.

[0038] The water content of the solid L1 after dehydration is preferably 3 to 35% by mass.

[0039] If the water content of the solid L1 is less than 3%, the compatibility with the resin during melt granulation with the resin, which will be described later, may deteriorate, and the masterbatch may not be uniformly dispersed in the resin masterbatch, which may result in the additive not being able to fully exert its effect in the resin molded product.

[0040] On the other hand, if the water content of the solid matter L1, that is, the water content, exceeds 35%, the foaming of the resin may not be sufficiently suppressed as intended.

[0041] (Melting and / or pressurized granulation step: S4) Next, in this embodiment, the dehydrated solid material L1 is melt-granulated.

[0042] The melt granulation process is carried out using a general-purpose kneader, such as a Banbury mixer, a pressure kneader, or a twin-screw extruder. The melting temperature varies depending on the type of additives that make up the solid material L1, and becomes higher as the additives, such as fibers or clay minerals, that have higher softening points are added, and is generally 150 to 280°C.

[0043] In the case of pressurized granulation, no heat is applied and a tablet press, extrusion granulator (disc pelleter), etc. is used.

[0044] Furthermore, the melt granulation process and the pressure granulation process can be used in combination.

[0045] By going through steps S1 to S4 as described above, a masterbatch L2 containing a plurality of additives can be obtained. The masterbatch obtained through the pressurized granulation process has a compressed powder shape, like a pharmaceutical tablet, and is water-soluble.

[0046] (Resin mixing and melt granulation process: S5) Next, the production of the resin masterbatch will be described. The resin masterbatch is produced by mixing an appropriate resin with the masterbatch obtained as described above, followed by melt granulation.

[0047] Resins that can be used in this embodiment include thermoplastic resins such as polycarbonate resin, polybutylene terephthalate (PBT resin), polyethylene terephthalate (PET resin), polyvinyl chloride, polystyrene, polyacetal resin, modified polyphenylene ether (modified PPE resin), ethylene-vinyl acetate copolymer, polyarylate, liquid crystal polyester resin, polyethylene resin, polypropylene resin, fluororesin, and polyamide resin (nylon). These may be used alone or in combination of two or more.

[0048] Various biodegradable resins may also be used, and these biodegradable resins may be used alone or in combination with the thermoplastic resins.

[0049] The melt granulation is carried out using a general-purpose kneader, such as a Banbury mixer, a pressure kneader, or a twin-screw extruder. The melting temperature varies depending on the type of resin, but is generally 120 to 280°C.

[0050] By going through the steps described above, the resin masterbatch L3 can be obtained.

[0051] The resin masterbatch L3 is then processed into a predetermined resin molded product or resin film by extrusion molding, injection molding, stretching, or the like.

[0052] As described above, according to the present embodiment, the solid material L1, which is the raw material for the masterbatch L2, is dehydrated before the masterbatch L2 is obtained, so that the water content in the masterbatch L2 can be sufficiently reduced and foaming when mixed with a resin can be suppressed.

[0053] Furthermore, even when an additive has poor thermal melting properties, such an additive is made into a masterbatch in advance, and then mixed with a resin and melt-granulated, so that the additive can be uniformly dispersed in the resin (masterbatch).

[0054] Furthermore, since the masterbatch L2 contains a plurality of additives, the additives can be dispersed uniformly in the resin without scattering in the factory or contaminating machines, as compared with when powder materials are used.

[0055] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims.

Claims

1. a step of mixing and kneading a plurality of additives, at least one of which is water-containing, to solidify the additives, thereby obtaining a solid material comprising the plurality of additives; dewatering the solid material; a step of melting and / or pressure granulating the dehydrated solid material to obtain a masterbatch; Including, A method for producing a masterbatch, wherein the dehydration is carried out by bringing the solid into contact with a hygroscopic liquid or a polymeric adsorbent.

2. a step of mixing and kneading a plurality of additives, at least one of which is water-containing, to solidify the additives, thereby obtaining a solid material comprising the plurality of additives; dewatering the solid material; a step of melting and / or pressure granulating the dehydrated solid material to obtain a masterbatch; a step of mixing the masterbatch with a resin and melt-granulating the mixture to obtain a resin masterbatch; Including, 10. A method for producing a resin masterbatch, wherein the dehydration is carried out by bringing the solid into contact with a hygroscopic liquid or a polymer adsorbent.

3. The method for producing a masterbatch according to claim 1 or the method for producing a resin masterbatch according to claim 2, wherein the masterbatch has a water content of 3 to 35 mass %.

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