JPS6364462B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to filler pellets for use in thermoplastic resins. In detail, powdered inorganic fillers, hydrogenated aromatic petroleum resins with a nuclear hydrogenation rate of 80% or more, and hydrogenated dicyclopentadiene petroleum resins with a bromination rate of 10 or less with an average molecular weight of 200 to 3000 and a softening point. The present invention relates to filler-containing pellets which are made of a hydrogenated resin at 80 to 150°C and which are mixed with a thermoplastic resin and have an average particle volume of 0.1 to 500 mm ³ . It has been well known that inorganic fillers are blended into thermoplastic resins in order to improve their physical properties and lower their prices. In such cases, the thermoplastic resin and the inorganic filler are weighed, melted and kneaded using a kneader such as a kneader to form a uniform thermoplastic resin compound containing the inorganic filler, and then cooled and pulverized.
Generally, the pellets are formed into pellets using an extruder and a pelletizer, and then fed to a hopper of a molding machine and molded. However, it is undesirable to perform this series of processes in the same molding factory because the dust during mixing and the final molded product will be mixed in the same factory. It is not advantageous to install machines, crushers, extruders, pelletizers, etc., as it requires a large amount of expense. Against this background, recently masterbatch pellets, which are thermoplastic resins such as polyethylene (PE) and polypropylene (PP) filled with inorganic fillers in large quantities, and amorphous polypropylene (APP) with low melt viscosity have been developed. Highly concentrated filler pellets are used in thermoplastic resin formulations. In the former case, the fluidity decreases significantly depending on the blended content of the inorganic filler powder, causing problems in processability and making it difficult to fill with a large amount of filler. The latter filler pellets have a low melt viscosity.
Because it is based on APP, it is possible to contain 70 to 85% by weight of inorganic filler, and the price is relatively low. However, when molding is performed, after cooling and solidifying, the binder of filler pellets is deposited on the surface of the product. The hot APP bleeds out, causing a decrease in product value in the case of molded products due to reduced gloss and surface adhesion, and in the case of films, it causes blocking. In addition, the physical properties are significantly deteriorated. The present invention has been made based on intensive research on the above-mentioned processing problems of filler-containing thermoplastic resins, and has succeeded in developing filler-containing pellets that are excellent in moldability, physical properties, and cost. It is based on this. That is, 90 to 50% by weight of a powdered inorganic filler, an average molecular weight of 200 selected from hydrogenated aromatic petroleum resins with a nuclear hydrogenation rate of 80% or more, and hydrogenated dicyclopentadiene petroleum resins with a bromine number of 10 or less. ~3000, consisting of 10~50% by weight of hydrogenated resin with a softening point of 80~150℃, average particle volume
The present invention provides an excellent filler-containing pellet for use in a thermoplastic resin having a size of 0.0 to 500 mm ³ . In the present invention, when filler-containing pellets are dry mixed with thermoplastic resin pellets and molded, the process fluidity is not reduced, and the heat resistance of the thermoplastic resin is improved.
It can improve physical properties such as dimensional stability and rigidity, and is also effective in reducing the amount of heat generated during incineration. In particular, the feature that conventional filler-containing pellets such as APP type do not have is that when mixed with PE or PP,
In addition to improving printability and paintability, which are major drawbacks of these resins, by mixing them with PE and PP for stretching, it lowers the thermocompression temperature in the processing process of woven and nonwoven fabrics, and prevents solidification after compression. Another advantageous feature is that it speeds up the process. Furthermore, polystyrene, acrylonitrile-based styrene copolymer,
Needless to say, it also exhibits excellent properties when applied to aromatic thermoplastic resins such as ABS resin. Each component of the present invention will be explained in detail below. The powdered inorganic filler referred to in the present invention usually refers to
It is an inorganic powder with an average particle size of 0.01μm to 500μm,
Examples include various types of light and heavy calcium carbonate, talc, clay, silica, aluminum hydroxide, diatomaceous earth, silica sand, mica powder, aluminum sulfate, barium sulfate, calcium sulfate, calcium sulfite, lithopone, pumice powder, glass powder, zinc. Magnesium carbonate, metal powder, asbestos powder, titanium oxide, slate powder, fly ash, volcanic glass hollow body, or a mixture thereof. The hydrogenated aromatic petroleum resin with a nuclear hydrogenation rate of 80% or more in the present invention is an aromatic aromatic petroleum resin obtained by polymerizing a petroleum fraction whose main component is a polymerizable aromatic hydrocarbon. It is a light-colored resin obtained by hydrogenating group components to a nuclear hydrogenation rate of 80% or more. This aromatic petroleum resin can be obtained by directly separating the cracked oil fraction with a boiling point range of 140 to 280°C from the cracked oil obtained by thermal decomposition of petroleum, or by further separating a specific fraction thereof. In addition to aromatic petroleum resins obtained by polymerization with heat or acid catalysts, these polymerizable aromatic hydrocarbons are copolymerized with other olefins, dienes, and terpenes in equal amounts or less. It also includes petroleum resins obtained by Conventionally known methods can be used for intranuclear hydrogenation. The intranuclear hydrogenation rate is calculated from the absorbance at 700 cm ^-1 according to the infrared absorption spectrum using the following formula. Intranuclear hydrogenation rate (%) = 100 x (1 - absorbance of petroleum resin after hydrogenation/absorbance of petroleum resin before hydrogenation) In the present invention, the intranuclear hydrogenation rate is 80% or more, more preferably 90%. % or more. If it is less than 80%, the heat resistance will be insufficient and when used as a blend with a thermoplastic resin, it will cause discoloration, which is undesirable. These hydrogenated aromatic petroleum resins with a nuclear hydrogenation rate of 80% or more are sold domestically by Arakawa Chemical Co., Ltd. under the trademark "Alcon P." In the present invention, the hydrogenated dicyclopentadiene petroleum resin having a bromine number of 10 or less refers to one or a mixture of two or more selected from cyclopentadiene, dicyclopentadiene, and alkyl substituted products thereof, or a mixture thereof together with these. It is a light-colored resin obtained by hydrogenating a dicyclopentadiene-based petroleum resin obtained by polymerizing a mixture with a copolymerizable component in an amount equal to or less than that using a heat or acid catalyst to a bromine number of 10 or less. Conventionally known methods can be used to hydrogenate these dicyclopentadiene petroleum resins. The degree of hydrogenation can be determined from the bromine number. The bromine number can be determined by the method of ASTM D1159-77, and in the present invention it is necessary that the bromine number is 10 or less, more preferably 5 or less. If the bromine number exceeds 10, the heat resistance will be insufficient and, when blended with a thermoplastic resin, it will cause discoloration, which is undesirable. These hydrogenated dicyclopentadiene resins with a bromine number of 10 or less are sold domestically by Etsuso Kagaku Co., Ltd. as the "Escolets 5000 Series." The hydrogenated petroleum resin selected from hydrogenated aromatic petroleum resins with a nuclear hydrogenation rate of 80% or more and hydrogenated dicyclopentadiene petroleum resins with a bromine number of 10 or less in the present invention has an average molecular weight of 200 to 3000, It is preferably between 300 and 2000. If the average molecular weight is 200 or less, the softening point will be low, which is undesirable, and if it is 3000 or more, moldability will be poor, which is not preferred. In addition, the softening point of these hydrogenated petroleum resins is 80 to 150 as measured by the ring and ball method (JIS-K-2207).
It is necessary that the temperature is preferably in the range of 90 to 140°C. If it is below 80°C, the filler-containing pellets will develop surface tackiness, which is undesirable, and if it is above 150°C, the molding processability will be poor, which is not preferable. Thermoplastic resins to which the filler pellets of the present invention can be applied include polyethylene, polypropylene, polybutene-1, copolymers thereof, polystyrene, acrylonitrile-styrene copolymers,
Commonly known thermoplastic resins include thermoplastic rubber, ABS resin, polyα-methylstyrene, polyvinyl chloride, polymethyl methacrylate, polycarbonate, polyamide, polyester, and polyacrylonitrile. Polyolefins such as polyethylene, polypropylene, polybutene-1, and copolymers thereof are preferred. The blending ratio in the thermoplastic resin can be appropriately selected depending on the application. The quantitative relationship between the powdered inorganic filler and the hydrogenated petroleum resin is such that the powdered inorganic filler has an average molecular weight of 200 to 200% by weight, preferably 85 to 60% by weight.
3000, hydrogenated petroleum resin 10-50 with softening point 80-150℃
% by weight, preferably 15 to 40% by weight, but if the hydrogenated petroleum resin is less than 10% by weight, the plasticized state is such that it remains fluid even when kneaded at high temperatures with a powdered inorganic filler. It cannot be formed into pellets. When the hydrogenated petroleum resin is more than 50% by weight, the fluidity is greatly improved, but the role of the hydrogenated petroleum resin in the filler-containing pellets of the present invention is to maintain the fluidity as a powder. If there is too much of this binder, not only the desired improvement in physical properties cannot be expected, but also the properties specific to the thermoplastic resin will be impaired. Furthermore, small amounts of antioxidants, processing aids, pigments, dyes, etc. can be added to the filler-containing pellets of the present invention, if necessary. The filler-containing pellets of the present invention have an average particle volume of 0.1 to 500 mm ³ , preferably 1 to 400 mm ³ ,
This is a general-purpose thermoplastic resin in powder form or volume.
This is because it is in the form of pellets or crumbs with a size of 500 mm ³ or less, and in order to fully demonstrate the function of the filler-containing pellets, the dry blend mixture with the thermoplastic resin must be maintained in a uniform mixed state in the hopper of the molding machine. Therefore, it is preferable that the volume of the pellets is approximately the same as that of the thermoplastic resin to be mixed. The shape of the filler-containing pellets may be spherical, cylindrical, or angular; when produced by an extruder-pelletizer method, a cylindrical shape is preferred. The formulation and preparation of these filler-containing pellets are as follows:
It can be easily mixed by machines used for kneading and mixing general-purpose plastics, such as kneaders, Henschel mixers, Banbury mixers, and rolls, but especially when the particle size of the inorganic filler is coarse, the mixture becomes liquid at high temperatures. Because of its high fluidity, it can be uniformly mixed in a short time at a temperature above the softening point of hydrogenated petroleum resin using a simple heatable mixing vessel. To pelletize this mixture, various methods can be applied, such as extruding the mixture using an extruder and cutting it (pelletizer method), pulverizing it into granules using a crusher, and forming sheets using rolls and shredding them. can do. The present invention will be explained in more detail below with reference to Examples. Examples 1-2 Hydrogenated aromatic petroleum resin (Alcon P115, hydrogenation rate 95% or more, softening point 115°C, Arakawa Chemical Industry Co., Ltd.)
2.1Kg, powdered inorganic filler: heavy calcium carbonate (K#300, Asahi Kosui Co., Ltd.) 12.75Kg, processing aid (HIWATUX 310MP, Mitsui Petrochemical Industries)
Co., Ltd. 0.15Kg was uniformly mixed at 150℃ using a 10 kneader, cooled and pulverized to obtain filler pellets with an average particle volume of ^25mm3 , and then this pellet and polypropylene pellets (Mitsui Noblen JHH-G, Mitsui Toatsu Chemical Co., Ltd. using a tumbler mixer,
After preparing a dry blend so that the heavy calcium carbonate content is 25% by weight and 50% by weight, this is injection molded to produce a molded product. A molding machine, screw L/D=15, CR2.5 was used) and the melt index (MI) of the injection product were measured and shown in Table 1. Comparative Examples 1-2 Polypropylene pellets (same as Example 1) and heavy calcium carbonate (same as Example 1) were
Prepared using a kneader at 10°C so that the heavy calcium carbonate content corresponded to Example 1 and Example 2.
After pelletizing, the pellets were injection molded and compared with Examples 1 and 2, as shown in Table 1. As is clear from Table 1, Examples 1 and 2 using the filler-containing pellets of the present invention have excellent fluidity as shown by the MI results, and the low torque during molding reduces the power consumption of the hydraulic motor. It was very economical, with reduced consumption and improved molding cycles due to faster charging, and the molded products also had a good appearance.

[Table] Comparative Example 3 Same as Example 1 except that unhydrogenated aromatic petroleum resin (Nisseki Neopolymer #120, Nippon Petrochemical Co., Ltd.) was used instead of hydrogenated aromatic petroleum resin. The injection moldability of the molded product and the MI of the injection product were measured, and the results were almost the same as in Example 1. However, when unhydrogenated aromatic petroleum resin was used, there was an odor during heating and mixing, which not only worsened the working environment, but also caused the filler-containing pellets to turn yellow due to discoloration due to thermal deterioration. Injection molding of flower pots using these pellets did not yield light-colored molded products, and the molding process also emitted an odor, which remained even after the final product was released from the mold. Furthermore, when the flowerpot was left outdoors, the surface exposed to sunlight gradually turned brown, making it a poor product. Examples 3 to 4 and Comparative Examples 4 to 5 Filler-containing pellets of the present invention were applied to low-density polyethylene (Lexron J50, Nippon Petrochemicals Co., Ltd.) and high-density polyethylene (Stafrene E791, Nippon Petrochemicals Co., Ltd.). Table 2 shows the composition of two types of filler-containing pellets prepared using hydrogenated dicyclopentadiene petroleum resin, and based on these, Examples 1-
Table 3 shows the moldability and physical properties when dry blending was performed in the same manner as in Example 2. Comparative Examples 4 and 5 were prepared by corresponding to Examples 3 and 4 in terms of the content of the inorganic filler. The formulation of Comparative Examples 4 and 5 is
This was carried out at 150°C using a 10 kneader, and the sheets were separated into 3-4 mm sheets using a roll mill, which were then cut into granules using a sheet cutter. From Table 3, in injection molding using a test specimen mold with a cavity capacity of 63 ml using pellets containing the filler of the present invention, Examples 3 and 4 had excellent fluidity and molding process as in the case of polypropylene of Examples 1 and 2. It was easy to process and it was possible to lower the processing temperature. Also, in terms of physical properties, they were equivalent to or better than Comparative Examples 4 and 5, indicating that the filler-containing pellets using hydrogenated petroleum resin have excellent applicability.

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Claims (1)

[Claims] 1. 90 to 50% by weight of a powdered inorganic filler and an average molecular weight of 200 to 200 selected from hydrogenated aromatic petroleum resins with an intranuclear hydrogenation rate of 80% or more and hydrogenated dicyclopentadiene petroleum resins with a bromine number of 10 or less. 3000, a filler-containing pellet for use in a thermoplastic resin containing 10 to 50% by weight of a hydrogenated petroleum resin with a softening point of 80 to 150°C and an average particle volume of 0.1 to 500 ^mm3 .