WO2007080872A1

WO2007080872A1 - Masterbatch for elimination of moisture in plastics and method for producing masterbatch for elimination of moisture in plastics

Info

Publication number: WO2007080872A1
Application number: PCT/JP2007/050130
Authority: WO
Inventors: Li Kong; Ying Zhang
Original assignee: Chukyo Shoji. Co., Ltd.; Positive Force Investments Corporation
Priority date: 2006-01-10
Filing date: 2007-01-10
Publication date: 2007-07-19
Also published as: MY143493A

Abstract

Disclosed is a masterbatch for elimination of moisture in plastics, which contains a dehumidifying agent and a thermoplastic resin as a binder. The dehumidifying agent is composed of an inorganic compound powder having moisture absorption properties and a surface modifying agent for covering the surfaces of inorganic compound particles. The surface modifying agent improves compatibility between the inorganic compound and the thermoplastic resin, and suppresses the moisture absorption function of the inorganic compound at room temperature, while allowing the inorganic compound to perform the moisture absorption function when heated.

Description

Specification

Plastic dehumidification masterbatch and method for producing plastic dehumidification masterbatch

Technical field

[0001] The present invention relates to a plastic dehumidification master batch and a method for producing a plastic dehumidification master batch.

Background art

[0002] In the case of various plastic molding methods such as injection molding, extrusion molding, T-die method, etc., moisture is vaporized by heating when plastic material containing water! / Is heated and melted. As a result, the surface of the molded product is likely to be blistered or cloudy, or a defect in appearance such as a water pattern or a fish eye is likely to occur. Such defects in the appearance of the molded product may occur even if the plastic material contains only about 0.5% by weight of water. Therefore, when molding a plastic material, generally, the plastic material is preliminarily dried (so-called pre-drying) with a hot air dryer or the like, and force is also used. In particular, pre-drying is not required when molding highly hygroscopic plastic materials such as ABS resin (acrylonitrile 'butadiene' styrene copolymer), nylon, polymethyl methacrylate, and poly vinyl chloride. Don't help, become things!

[0003] By the way, various types of master batches are conventionally used for molding plastics, and master batches containing hygroscopic agents or additives having hygroscopic properties have already been disclosed. For example, JP 2005-7837 A discloses a master notch containing a hygroscopic agent. This master batch is a master notch used for adding a hygroscopic agent to a plastic material when producing a plastic molded product that exhibits hygroscopicity with an internally added hygroscopic agent. If the hygroscopic agent absorbs moisture when manufacturing the masterbatch or storing the master notch, the hygroscopicity of the molded product will be reduced, and the hygroscopic agent will be dispersed in the plastic material when molding the plastic material. It becomes difficult. Therefore, this master batch is formed by coating the center part of the thermoplastic resin and the hygroscopic agent with the outer layer of the thermoplastic resin so that the hygroscopic agent in the central part is produced during the production and storage of the master batch. It has a structure that prevents moisture absorption.

[0004] Also, JP-A-10-45919 discloses a masterbatch containing alumina. This master batch contains alumina, a silane coupling agent, etc., in addition to the force colorant, which is a coloring masterbatch that is used to add a colorant to a plastic material when producing colored molded articles. ing. Alumina is generally hygroscopic although it is contained in this master batch to improve the physical properties of the molded product.

Disclosure of the invention

Problems to be solved by the invention

[0005] Although there are conventional masterbatches containing a hygroscopic agent and hygroscopic alumina, they do not exert a dehumidifying action when molding plastic materials. Therefore, it could not be used as a master batch to dehumidify plastic materials when molding plastic materials instead of pre-drying with a dryer.

[0006] The present invention makes it possible to dehumidify a plastic material in a short time and with low energy without heating for the purpose of drying, and it is possible to form a plastic material without preliminary drying by a dryer. It was an object to provide a master batch for plastic dehumidification. Means for solving the problem

[0007] One invention is a masterbatch that is mixed when a plastic material is molded, heated together with the plastic material, and melts with the plastic material, and includes a dehumidifying agent and a thermoplastic resin as a binder. And the dehumidifying agent improves the compatibility between the inorganic compound powder and the thermoplastic resin by covering the surface of the inorganic compound with a hygroscopic powder and the inorganic compound at room temperature. A surface modifying agent that suppresses the moisture absorption function of the inorganic compound when heated, and a plastic dehumidification masterbatch that absorbs moisture contained in the plastic material when it is molded, which is also effective.

[0008] Another invention is a method for producing a masterbatch comprising a dehumidifying agent and a thermoplastic resin as a binder, mixed when molding a plastic material, heated together with the plastic material, and melted with the plastic material. A powder of a hygroscopic inorganic compound, The dehumidifying agent is prepared by heating while contacting with a surface modifier, and after cooling the obtained dehumidifying agent, the cooled dehumidifying agent and the thermoplastic resin are mixed. It is a manufacturing method of a masterbatch.

The invention's effect

[0009] The plastic dehumidification masterbatch of the present invention (hereinafter sometimes simply referred to as "masterbatch") has the following effects.

First, since it contains a dehumidifying agent, it can be easily dehumidified by dispersing the dehumidifying agent in the plastic material simply by mixing it when molding the plastic material.

[0010] Second, when a masterbatch is produced, a thermoplastic resin is formed by covering the inorganic compound with a surface modifier that improves the compatibility with the thermoplastic resin and forming a dehumidifier. It is easy to disperse the dehumidifier in the cocoon. Therefore, a dehumidifying agent can be uniformly contained in the masterbatch, and by mixing the masterbatch quantitatively with the plastic material, the dehumidifying agent can be reliably mixed with the plastic material and dehumidified. .

[0011] Thirdly, the surface modifier that constitutes the dehumidifying agent coats an hygroscopic inorganic compound, thereby suppressing the hygroscopic function of the inorganic compound at room temperature and exerting the hygroscopic function of the inorganic compound during heating. When the dehumidifier is stored at room temperature before use, it easily absorbs moisture when heated together with the plastic material during use. Therefore, this masterbatch preserves the hygroscopic function of the inorganic compound before use, and when used, the hygroscopic function of the inorganic compound is reliably exerted to dehumidify the plastic material.

[0012] Fourth, since the dehumidifying agent is difficult to absorb moisture at room temperature, the dehumidifying function of the dehumidifying agent is unlikely to be impaired even if the master batch is exposed to a normal humidity environment during storage or preparation for use.

[0013] By exerting the above-described effects, according to the master batch of the present invention, the plastic material can be easily dehumidified by mixing with the plastic material when molding the plastic material. In the plastic material molding process The step of pre-drying the material can be omitted. Therefore, the molding process of the plastic material can be shortened, and the plastic material can be molded in a shorter time and with lower energy than before. In addition, since it is not necessary to heat the plastic material only for pre-drying, it is possible to prevent the plastic material from being overheated and deteriorated.

[0014] Next, according to the method for producing a plastic dehumidification masterbatch of another invention, the inorganic compound powder and the surface modifier are heated while being brought into contact with each other, compared with the case of non-heating. The entire surface of the inorganic compound can be more reliably coated with the surface modifier. Therefore, it is possible to efficiently prepare a dehumidifying agent and efficiently obtain a master batch for plastic dehumidification.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] The plastic dehumidification masterbatch of the present invention is a masterbatch that is used when molding a plastic material and dehumidifies the plastic material. This master batch contains at least a dehumidifying agent and a thermoplastic resin as a binder as basic components. When this master notch is mixed with the plastic material when molding the plastic material, the thermoplastic resin and the plastic material are melted by the heating during molding, and the dehumidifying agent is dispersed in the plastic material to absorb the moisture in the plastic material. can do.

[0016] The dehumidifying agent constituting the masterbatch is composed of an inorganic compound powder having hygroscopicity and a surface modifier for coating the surface of the inorganic compound.

[0017] The surface modifier constituting the dehumidifying agent coats the surface of each particle of the inorganic compound to improve the compatibility between the inorganic compound and the thermoplastic resin, and at the same time has a function of absorbing moisture of the inorganic compound. It is a substance that suppresses and exhibits the hygroscopic function of inorganic compounds during heating. As used herein, “suppressing the hygroscopic function of an inorganic compound” means inhibiting the hygroscopic function of the inorganic compound, and “exhibiting the hygroscopic function of an inorganic compound” means the hygroscopic function of the inorganic compound. It means not disturbing. Examples of such surface modifiers that can be used include titanate coupling agents, aluminum coupling agents, R << raffin, and stearic acids. These surface modifiers have an affinity for both inorganic compounds and thermoplastic resins and bind chemically or physically to the surface of the inorganic compound powder. This can improve the compatibility between the inorganic compound and the thermoplastic rosin. In addition, by heating in contact with the inorganic compound and covering the entire surface of the inorganic compound, the hygroscopic function of the inorganic compound can be suppressed at room temperature, and the hygroscopic function of the inorganic compound can be reliably exerted during heating. The theoretical basis for this is not always clear, but these surface modifiers are in a state where the tissue is difficult for water molecules to pass through at room temperature, and the tissue changes into a relaxed state that allows water molecules to pass through heating. It is thought to do. Surface modifiers are not limited to these, and only one type may be used alone, or two or more types may be used in combination.

[0018] As the titanate coupling agent, conventionally known ones can be used. For example, use isopropyl triisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraoctyl bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate Can do. A conventionally well-known thing can be used as said aluminum type coupling agent. For example, aluminum isopropylate, aluminum ethylate, aluminum tris (ethyl acetate acetate), ethyl acetate acetate aluminum diisopropylate and the like can be used. A conventionally well-known thing can be used as said paraffin. For example, fluid paraffin, polyethylene << raffin wax, polyethylene wax and the like can be used. As the stearic acid, in addition to stearic acid, stearic acid salts such as calcium stearate and magnesium stearate can be used.

[0019] The ratio of the surface modifier contained in the dehumidifier is preferably a ratio sufficient to cover at least the entire surface of the powder of the inorganic compound in order to suppress the hygroscopic function of the inorganic compound at room temperature. . Therefore, the proportion of the surface modifier can be appropriately set depending on the surface area of the inorganic compound, but in general, the proportion of the surface modifier relative to 100 parts by weight of the inorganic compound is 1 part by weight or more and 40 parts by weight or less, preferably 1 part by weight. Part to 10 parts by weight, more preferably 1 part to 5 parts by weight. If the amount of the surface modifier exceeds 40 parts by weight relative to 100 parts by weight of the inorganic compound, the compatibility between the inorganic compound and the thermoplastic resin does not improve much with respect to the amount of surface modifier added, and in the master notch. This is not preferable because the dehumidifying agent may aggregate. 1 to 5 parts by weight more efficient The dehumidifying agent can be uniformly dispersed in the master batch.

[0020] The inorganic compound constituting the dehumidifying agent is a powdery inorganic compound having hygroscopicity, and is a chemically hygroscopic inorganic compound that absorbs moisture by a chemical reaction with moisture, or an adsorption that absorbs moisture by adsorbing moisture. Functional inorganic compounds can be used. Only one inorganic compound may be used alone, or two or more inorganic compounds may be used in combination. Preferably, at least one chemically hygroscopic inorganic compound is used. If a chemically hygroscopic inorganic compound is used, moisture can be more reliably absorbed under heating conditions. More preferably, the chemically hygroscopic inorganic compound and the adsorptive inorganic compound are used in combination. Inorganic compounds, although moisture absorption is suppressed by the surface modifier at room temperature, actually absorb completely and are not completely inhibited. However, the combined use of the chemically hygroscopic inorganic compound and the adsorptive inorganic compound can more reliably suppress the moisture absorption of the chemically hygroscopic inorganic compound at room temperature, and the master batch can be stored for a long time. Become. The theoretical basis for this is not necessarily clear, but it is considered that the adsorptive inorganic compound absorbs moisture preferentially over the chemically hygroscopic inorganic compound at room temperature.

[0021] Examples of the chemically hygroscopic inorganic compound include calcium carbonate, barium oxide, and aluminum oxide. These inorganic compounds are suitable for use because they are highly reactive with moisture and absorb moisture quickly, and among them, calcium carbonate is highly safe and can be most preferably used. The chemically hygroscopic inorganic compound used in the present invention is not limited to these as long as it is an inorganic compound that absorbs moisture by a chemical reaction with moisture, but also calcium chloride, magnesium chloride, magnesium sulfate, sulfuric acid. Calcium or the like can also be used.

[0022] Examples of the adsorptive inorganic compound include zeolite, silica gel, diatomaceous earth, and the like. Since these are porous and excellent in hygroscopicity, they can be suitably used. The adsorptive inorganic compound used in the present invention is not limited to these as long as it is an inorganic compound that absorbs moisture by adsorbing moisture.

[0023] The powder of the inorganic compound preferably has a particle size of 20 µm or less. If the particle size is 20 μm or less, even if it is added to a plastic material that has a large surface area per unit weight and good dehumidification efficiency, the moldability will be impaired, and the physical properties and appearance of the resulting molded product will deteriorate. evil It will not be made. More preferably, the particle diameter is 3 / zm or more and 10 / zm or less. Note that the particle size of 20 m or less does not necessarily mean that the particle size of all inorganic compound powders must be 20 m or less, for example, the particle size of 97% or more of powders is 20 μm or less. If so, an effect can be obtained. The particle diameter can be measured with a laser particle diameter measuring instrument, and the major axis of the measured particle can be used as the particle diameter.

[0024] The proportion of the dehumidifying agent contained in the masterbatch is preferably 5 wt% or more and 90 wt% or less. If it is less than 5% by weight, it is not preferable because a large amount of master batch must be prepared in order to remove moisture contained in the plastic material. On the other hand, if it exceeds 90% by weight, the moldability of the master batch deteriorates, which is not preferable. More preferably, it is 20 to 80% by weight, and most preferably 40 to 60% by weight.

[0025] The masterbatch of the present invention contains thermoplastic rosin. This thermoplastic resin functions as a binder that binds the dehumidifying agent and other constituents contained in the masterbatch to each other, and is sometimes referred to as a carrier resin. Examples of the thermoplastic resin used in the present invention include ABS resin (acrylonitrile 'butadiene' styrene), polyethylene, polypropylene, polyethylene terephthalate, polymethyl methacrylate, SBS (styrene 'butadiene' styrene copolymer), Examples include EVA (polybutyl alcohol), polyoxyethylene, nylon, polystyrene, and polybutylene terephthalate. The thermoplastic resin used in the present invention is not limited to these, and other types of thermoplastic resin can be used.

[0026] It is preferable to use a thermoplastic resin having good compatibility with the plastic material to which the masterbatch is added. More preferably, the same type of thermoplastic resin as the plastic material to which the masterbatch is added is used. For example, when the plastic material to which the masterbatch is added is ABS resin, it is most preferable to use the same type of ABS resin as the thermoplastic resin used in the masterbatch. SBS, EVA, etc., which are compatible with these, can also be suitably used. Only one type of thermoplastic resin may be used alone, or two or more types may be used in combination.

[0027] The ratio of the thermoplastic resin contained in the masterbatch of the present invention is 90% by weight or less. preferable. More preferably, it is 40 wt% or more and 60 wt% or less. When the ratio of the thermoplastic resin is within this range, the moldability when producing the master batch is improved.

[0028] The plastic dehumidification masterbatch of the present invention may contain additives such as a lubricant, a plasticizer, a heat stabilizer, an antioxidant and the like in addition to the dehumidifier and the thermoplastic resin. wear.

[0029] A lubricant can be added to the masterbatch of the present invention. Thereby, in the master notch manufacturing process, the moldability of the master batch can be stabilized, and friction with the plastic material when the master notch is added to the plastic material can be reduced. A conventionally well-known thing can be used as a lubricant. Only one type of lubricant may be used alone, or two or more types may be used in combination. Specific examples of the lubricant used in the present invention include, but are not limited to, the following.

[0030] Examples of the lubricant include hydrogen carbonate lubricants such as liquid paraffin, paraffin wax, and polyethylene wax, fatty acid lubricants such as stearic acid, metal stearates such as calcium stearate, zinc stearate, magnesium stearate, and zinc stearate. Examples include tendon-based lubricants. Among these, stearic acid is excellent in compatibility with various thermoplastic rosins, and therefore can be suitably used.

[0031] The ratio of the lubricant contained in the master batch is preferably 15% by weight or less. This is because if the lubricant is contained in an amount of more than 15% by weight, the molding material is lost due to slippage of the constituent materials of the master batch when the master batch is molded. The ratio of the lubricant is more preferably 3% by weight or more and 6% by weight or less. When the ratio of the lubricant is within this range, the lubricity between the constituent materials can be improved and the moldability can be kept good when the master batch is molded. In addition, when the masterbatch is added to the plastic material, friction between the masterbatch and the plastic material can be moderately moderated.

[0032] A plasticizer can be added to the master batch of the present invention, whereby the moldability of the master batch can be further improved. The plasticizer may be used for plastic molding as long as it is compatible with the thermoplastic resin contained in the masterbatch. Various plasticizers can be used. Only one type of plasticizer may be used alone, or two or more types may be used in combination. Specific examples of the plasticizer include, but are not limited to, the following.

[0033] Examples of the plasticizer include phthalate esters such as diheptyl phthalate (DHP), di-2-ethylhexyl phthalate (DOP), diisanol phthalate (DINP), and diisodecyl phthalate (DIDP). Plasticizers, aliphatic dibasic esters such as di-2-ethylhexyl adipate (DOA), disononyl adipate (DINA), di-2-ethylhexyl sebacate (DOS), epoxy soy bean oil, epoxy dihydro oil, Examples thereof include epoxy plasticizers such as epoxy stearic acid puchinole, epoxyhydrophthalate dioctyl, bisphenol A diglycidyl ether, and the like. Among these, phthalate ester plasticizers can be suitably used because they are excellent in compatibility with various thermoplastic resins and have good heat resistance and cold resistance. The proportion of plasticizer contained in the masterbatch is preferably 50% by weight or less. More preferably, it is 3 to 8% by weight.

[0034] A heat stabilizer can be added to the masterbatch of the present invention, thereby preventing discoloration of the thermoplastic resin due to heating during molding of the master notch. As the heat stabilizer, various heat stabilizers used in plastic molding cases can be used. Only one type of heat stabilizer may be used alone, or two or more types may be used in combination. Specific examples of heat stabilizers include, but are not limited to, the following.

[0035] Examples of the heat stabilizer include aliphatic carboxylate lithium stearate, magnesium stearate, calcium laurate, calcium linoleate, calcium stearate, barium ricinoleate, barium stearate, zinc laurate, and zinc ricinoleate. , Aliphatic carboxylate heat stabilizers such as zinc stearate, dimethyltin bis 2-ethylhexylthioglycolate, organic Zmercapands such as mono-Z dimethyltin stearoxychetyl mercaptide, dibutyltin maleate, dibutyltin Organotin maleates such as bisbutyl maleate, dibutyltin dilaurate, dibutyltin bis-2-ethylhexylthioglycolate, dibutyltin β-mercaptopropionate, and dioctyltin dilaurate, dioctyl Tin bis 2-ethylhexyl thioglycolate, etc. Various organotin heat stabilizers such as organotin carboxylates can be exemplified. The proportion of the heat stabilizer contained in the master batch is preferably 10% by weight or less. More preferably, it is 1% by weight or more and 3% by weight or less.

[0036] An antioxidant can be added to the masterbatch of the present invention, whereby the thermoplastic resin can be prevented from acidifying by heating during the production of the masterbatch, thereby preventing the quality from deteriorating. . As the anti-oxidation agent, various types of anti-oxidation agents generally used for plastic forming force are used as long as they are compatible with the thermoplastic resin contained in the masterbatch. be able to. Only one type of anti-oxidation agent may be used alone, or two or more types may be used in combination. Specific examples of the anti-oxidation agent include the following, but are not limited thereto.

[0037] Examples of the antioxidant include 2, 6 tert-butyl-4 methylphenol, n-otadecyl-3- (3 ', 5, -di-tert-butyl-4, hydroxyphenol) propionate, tetrakis [Methylene-3- (3 ', 5, di-tert-butyl 4-hydroxyphenol) propionate] Methane, tris (3,5-di-tert-butyl 4-hydroxybenzyl) isocyanurate, tri Ethylene glycol bis [3- (3-tert-butyl-4-hydroxy-5-methylphenol) propionate], 2,2, -methylenebis (4-methyl-6t-butylphenol), 4,4'-thiobis (3-methyl-) 6-t butylphenol), 4, 4'-butylidenebis (3-methyl-6-t butylphenol) and other phenolic antioxidants, dilauryl 3, 3, monothiodipropionate, dimyristyl 3, 3 -Sulfur antioxidants such as thiocypropionate, distearyl-3,3, monothiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate), trisnoyl ferrule phosphate, distearyl pentaerythritol di Phosphate acids such as phosphite, tris (2,4 di-t-butylphenol) phosphite, tetrakis (2,4 di-tert-butylphenol) 4,4'-biphenyl-enzyme phosphite An anti-wrinkle agent and the like can be exemplified. The proportion of the antioxidant contained in the master batch is preferably 15% by weight or less. In addition, although the blending ratio standard of the dehumidifying agent, the thermoplastic rosin, and various additives is shown, it goes without saying that they should be prepared within a range that adds them all to 100% by weight.

[0038] Hereinafter, a method for producing a master batch of the present invention will be described. Master of the present invention The notch can be manufactured through the following first to third steps.

[0039] [First step]

First, in the first step, the inorganic compound powder and the surface modifier are mixed while heating to coat the surface of the inorganic compound with the surface modifier to obtain a dehumidifying agent. The heating temperature at this time is preferably 90 ° C or higher and 130 ° C or lower. Various agitators having a heating function can be used for mixing. For example, using a Nauter mixer, a ribbon mixer, a Henschel mixer, a super mixer, etc. with a jacket, it is possible to mix while heating by passing heated oil through the jacket.

[0040] [Second step]

Next, in the second step, first, the dehumidifying agent obtained in the first step is cooled to 40 ° C. or lower. Here, the cooling may be active cooling such as flowing cold water through the jacket of the stirrer, or may be allowed to cool. Next, the cooled dehumidifying agent is mixed with the thermoplastic resin and, if necessary, various additives (such as a lubricant, a plasticizer, a heat stabilizer, and an antioxidant). Various agitators can be used for mixing, as in the first step.

[0041] [Third step]

Next, in the third step, the mixture obtained in the second step is heated to 90 ° C or higher and 220 ° C or lower to form a predetermined shape such as a dice, cylinder, sphere, or flat sphere. And get master notch. In the third step, various extruders capable of being heated and kneaded can be used. In particular, the use of a twin-screw extruder is preferred because a master batch can be obtained with a good appearance in which inorganic compound powder is uniformly dispersed. If it is a twin-screw extruder with a vacuum function, the volatile components generated by heating the mixture can be removed, and a master batch having a better appearance can be obtained.

[0042] The plastic dehumidification masterbatch of the present invention can be used by mixing with various plastic materials. For example, ABS resin, nylon, polymethyl methacrylate, polyvinyl chloride, polyethylene terephthalate, polybutylene terephthalate, polycarbonate, etc. are added to thermoplastic resin that requires special pre-drying in the conventional method. Can also be used. In addition, it can be used by adding to a thermoplastic resin moistened by improper storage. In addition, after use, recycle resin It is also possible to use it by adding it to (regenerated resin).

[0043] Hereinafter, a method for forming a plastic material using the plastic dehumidification masterbatch of the present invention will be described. First, the master batch of the present invention is added to a plastic material. It is preferable to use a master batch in which the thermoplastic resin contained in the master batch is compatible with the plastic material to which the master batch is added. It is more preferable if the thermoplastic resin contained in the masterbatch is the same type as the plastic material to be added to the masterbatch. The proportion of the masterbatch added to the plastic material can be determined as appropriate depending on the moisture content of the plastic material, but it is usually 6% by weight or less. In addition to the master notch, various additives such as a plasticizer, a heat stabilizer, and an antioxidant can be added to the plastic material as necessary.

Next, the plastic material to which the master batch has been added is molded by various known molding methods such as an extrusion molding method, an injection molding method, and a T-die method. Generally, when molding a plastic material, the plastic material is heated and melted. When the plastic material is heated, the plastic material and the master batch are melted together, and the dehumidifying agent contained in the master batch is dispersed in the plastic material. At this time, since the inorganic compound powder is covered with the surface modifier, the dehumidifier has an affinity for the plastic material and is uniformly dispersed in the plastic material. Further, when heated together with this, the suppression of the hygroscopic function of the inorganic compound by the surface modifier is released, and the hygroscopic function of the inorganic compound is exhibited. As a result, the dehumidifying agent spreads quickly to every corner of the plastic material, and the moisture in the plastic material can be absorbed and removed efficiently. Therefore, if the master batch of the present invention is used, the plastic material can be molded without pre-drying.

[0045] The molded body thus obtained does not have a defect in appearance due to the evaporation of moisture, although the plastic material as a raw material is not preliminarily dried. In addition, since heating for pre-drying is not required, discoloration of plastic materials and deterioration of physical properties due to over-drying are not caused. Since it does not require long-time heating for pre-drying, the plastic material can be molded in a short time and with less energy! The As a result, it is possible to realize a molded body of a plastic material that is low in cost and is environmentally friendly.

Example 1

[0046] In Example 1, acid calcium carbonate powder having a particle diameter of 10 μm is prepared as an inorganic compound, stearic acid is used as a surface modifier, polyethylene is used as a thermoplastic resin, and polyethylene wax is used as a lubricant. Through the process, No. 1 master batch was created. Table 1 shows the composition ratio. Polyethylene wax not only functions as a lubricant, but also functions as a dispersant for dispersing calcium oxide powder in a thermoplastic resin, and also functions as a plasticizer.

[0047] [Table 1]

[0048] The prepared master notch (No. 1) was added to a pre-dried polyethylene resin pellet containing 1% by weight of water, and a film was formed by the T-die method. As a result, it was possible to obtain a polyethylene film having no defects in appearance. In addition, the master batch (No. 1) was added to recycled polyethylene resin pellets containing 0.5 wt ^% / ₀ moisture which had not been pre-dried, and a film was formed by the T-die method. As a result, it was possible to obtain a recycled polyethylene film having no defects in appearance.

Example 2

[0049] In Example 2, acid calcium carbonate powder having a particle size of 8 μm as an inorganic compound, stearic acid as a surface modifier, ABS resin and SBS as a thermoplastic resin, magnesium stearate as a lubricant, and EBS (ethylene bis-stearic acid amide) and DO P (di-2-ethylhexyl phthalate) as a plasticizer were prepared, and a master batch No. 2 was prepared through the above first to third steps. The composition ratio is shown in Table 2.

[0050] [Table 2] N o. 2

Composition

Content (wt%) Inorganic compounds Calcium oxide 50

Surface modifier Stearic acid 1-5

A B S resin 12

Thermoplastic resin

S B S 30

Magnesium stearate 1.5

Lubricant

E B S 1.5

Plasticizer D O P 3.5

[0051] The prepared master notch (No. 2) was added in the range of 1 wt% to 2 wt% with respect to the ABS resin that had not been pre-dried, and molded by an injection molding method. As a result, it was possible to obtain a molded body of ABS resin with no defects in appearance.

Example 3

[0052] In Example 3, a calcium oxide powder having a particle size of 8 μm as an inorganic compound, stearic acid as a surface modifier, SBS as a thermoplastic resin, magnesium stearate and polyethylene wax as a lubricant, filling Calcium carbonate was prepared as an agent and blended in the proportions shown in Table 3 to prepare No. 3 and No. 4 master batches. Note that No. 3 creates a master batch through the above first to third steps, and No. 4 omits the first step in the first to third steps, and the second step A master batch was prepared by adding calcium. Next, each master batch was allowed to stand in a natural environment for 24 hours and then visually observed to examine changes in size and color. Furthermore, 94% by weight of ABS fat was mixed with 6% by weight of a masterbatch that was allowed to stand for 24 hours in a natural environment and injection molded to obtain a container. The obtained container was visually observed to check for defects in appearance. The results are shown in Table 3.

[0053] [Table 3] No. 3 No. 4 Inorganic compound Calcium oxide BO 50 Surface modifier Stearic acid 1.5

Ripe plasticity

S B S 30 30 Resin

Composition

stearic acid

1. 5 1. 5 Magnesium

Lubricant

Polyethylene

4 4 Wax

Filler Calcium carbonate 13 14. 5

Master after standing for 24 hours Size No change Expansion

—Batch appearance Color No change Whitening

Yes Appearance of container (existence of defects) No

(Water pattern)

No. 3 masterbatch and No. 4 masterbatch differ in the form of the inorganic compounds contained. That is, in No. 3, the inorganic compound is covered with the surface modifier, whereas in No. 4, the inorganic compound is not covered with the surface modifier and is contained as it is. ing. First, when comparing the appearance of a container made by adding a master batch left in a natural environment for 24 hours, the surface of the container of No. 3 is smooth and free of defects. There was a water-like pattern on the surface. This is because the No. 3 masterbatch sufficiently dehydrated the water in the ABS resin, while the No. 4 masterbatch cannot completely dehumidify the water in the ABS resin. It is inferred that the water remaining in the container evaporated and a water-striped pattern was formed on the surface of the container. Next, comparing the appearance of the masterbatch after standing for 24 hours, No. 3 is unchanged, while No. 4 is expanded and whitened. As a result, the inorganic compound (calcium oxide) contained in the No. 3 master batch hardly absorbs moisture, but the inorganic compound contained in the No. 4 master patch is presumed to have absorbed a large amount of moisture in the air. It is done. Based on the above, when the inorganic compound is not covered with a surface modifier (No. 4), moisture content in the air is absorbed during storage and the moisture absorption function is significantly reduced. It became clear that they could not absorb enough. On the other hand, when the inorganic compound is covered with a surface modifier (No. 3), the moisture absorption function of the inorganic compound is preserved in a normal natural environment. As a result, it has become clear that ABS can be sufficiently dehumidified. Example 4

In Example 4, first, calcium oxide powder having a particle size of 10 μm and zeolite having a particle size of 10 μm were used as the inorganic compound, stearic acid was used as the surface modifier, polyethylene was used as the thermoplastic resin, and polyethylene wax was used as the lubricant. The master batches No. 5 and No. 6 were prepared through the first and third steps. The composition ratio is shown in Table 4. Next, after leaving the obtained master patches No. 5 and No. 6 in a natural environment for 36 hours, each of the master batches was pre-dried and regenerated containing 0.5% by weight of water. A film was formed by mixing with polyethylene resin. At this time, the masterbatch was added to the recycled polyethylene resin so that the masterbatch force was 3% by weight. The obtained film was visually observed to investigate the appearance of defects. In this survey, the appearance defect caused by moisture volatilization during molding, such as a water-pattern appearance defect, is referred to as “water-pattern defect”, and the appearance defect due to the generation of particulate impurities is referred to as “particulate defect”. The presence or absence of each was confirmed. The results are shown in Table 4.

[0056] [Table 4]

The No. 5 masterbatch and No. 6 masterbatch differ in the inorganic compounds that make up the dehumidifier. In other words, No. 5 contains only one kind of acid-hypercalcium which is a chemically hygroscopic inorganic compound, whereas No. 6 contains zeolite, which is an additional inorganic compound in addition to calcium oxide. It differs in that it contains. None of the films formed using a masterbatch that was allowed to stand for 36 hours before use produced water-like defects. For this reason, the moisture absorption function of each masterbatch was suppressed before use, and a certain dehumidification function was ensured. It turns out that it got wet. However, particulate defects occurred only in the No. 5 film. This is because the acid and calcium strength contained in the No. 5 master patch gradually absorbs moisture before use, and the surface became harder over time, so that part of it was not compatible with polyethylene resin during film formation. It is assumed that it appeared on the film surface as an impurity. On the other hand, No. 6 has no particulate defects, and it can be seen that the surface of the calcium oxide was hardened before use, so that it absorbed moisture. From the above, it is clear that the moisture absorption of the chemically hygroscopic inorganic compound during storage can be more reliably suppressed by further containing the adsorptive inorganic compound in addition to the chemically hygroscopic inorganic compound. It became.

Example 5

In Example 5, first, a titanate coupling agent, an aluminate coupling agent, and raffine were prepared as surface modifiers, and the stearic acid of master patch No. 5 prepared in Example 4 above was prepared. Instead, No. 7-9 master batches were prepared using the prepared surface modifiers. The composition is shown in Table 5.

Next, the master batches of No. 5 and Nos. 7 to 9 were left in a natural environment, and the appearance of the master batch was visually observed after 24 hours and after 36 hours to check for changes in appearance. The results are shown in Table 5.

[0059] [Table 5]

After standing for 24 hours, the appearance of the misaligned master patch will change, so that in addition to stearic acid, titanate coupling agents, aluminate coupling agents and paraffin! It was confirmed that the moisture absorption of the compound (acid calcium) was suppressed. If the master batch is left for a long time, only No. 9 will turn white after 36 hours. The other Nos. 5, 7 and 8 did not change. This indicates that stearic acid, titanate-based coupling agents, and aluminate-based coupling agents have a greater effect of suppressing the hygroscopic function of inorganic compounds at room temperature than norafine.

Example 6

[0061] In Example 6, first, the master batch No. 9 prepared in Example 5 above was changed to 40% by weight of calcium oxide and 10% by weight of zeolite in the master compound No. 10, and a master batch of No. 10 was prepared. . Next, the obtained master batch No. 10 was left in a natural environment in the same manner as in Example 5 above, and after 36 hours, the appearance of the master batch was visually observed to check for changes in appearance. As a result, it was confirmed that there was no change in appearance after 36 hours.

[0062] The master batch of No. 10 is different from the master batch of No. 9 only in that it contains a dehumidifier composed of zeolite, which is only a dehumidifier having a calcium oxide power as a dehumidifier. The appearance of the masterbatch after standing for 36 hours was whitened for No. 9, whereas no change was observed for No. 10. From this, it can be seen that in the No. 10 master batch, the moisture absorption of the oxidizing power Lucium is more reliably inhibited. As a result, the combined use of a chemically hygroscopic inorganic compound and an adsorptive inorganic compound inhibits the moisture absorption of the chemically hygroscopic inorganic compound for a longer period of time than the adsorption of the chemically hygroscopic inorganic compound only by the surface modifier. It was revealed that the master batch can be stored for a long time.

Claims

The scope of the claims

[1] A masterbatch that is mixed when molding a plastic material, heated together with the plastic material, and melts into the plastic material,

Containing a dehumidifying agent and thermoplastic rosin as a binder,

The dehumidifying agent coats the surface of the inorganic compound having a hygroscopic property and the surface of the inorganic compound to improve the compatibility between the inorganic compound and the thermoplastic resin, and at a normal temperature, absorbs moisture of the inorganic compound. A plastic dehumidification masterbatch that absorbs moisture contained in the plastic material when the plastic material is molded, and a surface modifier that suppresses the function and exhibits a moisture absorption function of the inorganic compound during heating.

[2] The surface modifier is a surface modifier heated when the surface of the inorganic compound is coated, and the surface modifier includes a titanate coupling agent, an aluminate coupling agent, norafines, 2. The plastic dehumidification masterbatch according to claim 1, wherein the masterbatch is at least one selected from the group consisting of stearic acids.

[3] The plastic dehumidification masterbatch according to claim 1 or 2, wherein the inorganic compound is a chemically hygroscopic inorganic compound that absorbs moisture by a chemical reaction with moisture.

[4] The plastic dehumidification masterbatch according to claim 3, wherein the chemically hygroscopic inorganic compound is at least one selected from the group consisting of calcium oxide, barium oxide, and aluminum oxide.

[5] In addition to the dehumidifying agent composed of the chemical hygroscopic inorganic compound, it further contains a dehumidifying agent composed of an adsorptive inorganic compound that absorbs moisture by adsorbing moisture. Item 5. A master batch for plastic dehumidification according to Item 4.

6. The plastic dehumidification masterbatch according to claim 5, wherein the adsorptive inorganic compound is at least one selected from the group consisting of silica gel, zeolite and diatomaceous earth.

[7] A method for producing a master batch comprising a dehumidifying agent and a thermoplastic resin as a binder, mixed when molding a plastic material, heated together with the plastic material, and melted with the plastic material,

The dehumidifying agent is prepared by heating while bringing a powder of an inorganic compound having hygroscopicity into contact with a surface modifier, and after cooling the obtained dehumidifying agent, the cooled dehumidifying agent and The manufacturing method of the masterbatch for plastic dehumidification which mixes the said thermoplastic resin.