JP5598835B2 - Extruder for resin material evaluation - Google Patents

Description

  The present invention relates to a resin material evaluation extruder capable of evaluating extrusion characteristics such as moldability and viscosity with a small amount of sample.

  In recent years, with the increase in added value of resin materials, development aimed at materials having desired physical properties and functions has been actively conducted. In the screening stage in the initial stage of research and development, the resin material is generally polymerized in units of several grams to several hundred grams. Patent Document 1 describes a device that circulates a material melted in a screw part by providing a bypass channel from a barrel tip as a device for kneading in a small amount. Although this apparatus can evaluate the kneadability of the resin material in a small amount, it has not yet been evaluated for quantitative extrusion moldability. Non-Patent Document 1 describes an apparatus for kneading a small amount of material by providing a bypass flow path as in Patent Document 1, and according to this apparatus, by installing a pressure sensor in the bypass flow path, Viscosity can be measured simultaneously. However, this apparatus does not have a mechanism for ensuring quantitativeness, and has a problem that it is difficult to quantitatively perform extrusion molding at the same time as measuring viscosity approximately.

JP 2004-351930 A

Measurement of material properties / Evaluation of solution properties (Internet <http://www.eko.co.jp/eko/c/c0503-fr.html>)

  Accordingly, an object of the present invention is to provide an extruder for evaluating a resin material that enables quantitative extrusion and can accurately evaluate the extrusion characteristics such as flow characteristics and moldability of the resin material with a small amount of sample. is there.

  According to the present invention, there is provided a resin material evaluation extruder provided with a supply port, a heating and kneading unit, a pressure unit, and a discharge port, provided between the front end of the pressure unit that supplies the resin material and the discharge port. A gear pump, a resin reflux path for circulating the molten resin material from the pressurizing unit through the gear pump to the heating kneading unit of the extruder, or a discharge port provided on the downstream side of the gear pump for extruding the resin material to the die at the tip of the extruder Alternatively, there is provided an extruder for evaluating a resin material, which includes a flow path switching unit that flows to the resin reflux path and at least two pressure sensors provided in the resin reflux path.

  According to the preferable aspect of this invention, the extruder for resin material evaluation provided with the single screw or the multi-screw in the extruder is provided.

According to a preferred embodiment of the present invention, there is further provided an extruder for evaluating a resin material, wherein the internal capacity of the extruder is 100 cc or less and the volume of one groove of the gear pump is 1 to 60 mm ³ .

In recent years, with the aim of creating new high-value-added resin materials that are competitive, development of enormous types of resin materials has been promoted using small-scale (gram unit) samples by methods such as combichem (combinatorial chemistry). ing. About 100 g of the promising resin material narrowed down by these evaluations is made as a trial, and the viscosity and the like are evaluated. For samples selected from these, it is usually possible to evaluate practical formability only after pilot production in units of several tens to several hundred kg. On the other hand, if it evaluates using the extruder of this invention, with a small sample of 20-30g, the viscosity of a resin material and molding process aptitude, such as a film, can be evaluated simultaneously, and the development period and development of a new resin material Cost and development energy can be drastically reduced, and this is an environmentally friendly technology in terms of CO ₂ reduction. For example, the amount of power used for pilot plant operation can be reduced, and the amount of monomer raw materials such as ethylene and propylene, solvents, noble metal catalysts, cooling water, and heating steam used at that time can be greatly reduced. . Actually, as a result of evaluation using a 30 g film or sheet molding material, the relationship between the ratio of the discharge rate and take-up speed (draw ratio), which is an index of moldability, and the film width was confirmed by a practical production machine. And agreed well. At the same time, the viscosity of the resin material up to about 1000 s ⁻¹ was in good agreement with the existing viscometer. Furthermore, compared to pilot-produced extruders, the power consumption of heaters and motors can be reduced by approximately 30-80% per hour, and the usage of resin materials can be reduced by 95% or more per hour. can do. Therefore, according to the present invention, in addition to the viscosity at the time of melting, an extrusion molding performance evaluation can be performed with a very small amount of sample as compared with the conventional one at a low development cost and a short development period, and this is an environmentally friendly technology.

It is a figure which shows the time dependence of discharge amount when not considering the pressure in the gear pump upstream part of the extruder for resin material evaluation which concerns on this invention. It is a figure which shows the time dependence of discharge amount when the pressure in the gear pump upstream part of the extruder for resin material evaluation which concerns on this invention is made constant. It is a schematic diagram which shows an example of the extruder for resin material evaluation which concerns on this invention. It is a figure which shows the shear viscosity curve measured using the extruder for resin material evaluation which concerns on this invention. It is a figure which shows the film moldability implemented using the extruder for resin material evaluation which concerns on this invention.

The present inventors are small extruders having an internal capacity of, for example, 100 cc or less, preferably 50 cc or less, more preferably 30 cc or less, including the tip of the pressure portion of the resin material in the extruder, and finally the molten material to the middle of the extruded discharge port, the volume of one groove 1～60Mm ^3, preferably by providing a gear pump of 10 to 30 mm ^3, it allows for quantitative extrusion of small amounts of the solution the resin material. When the volume of one groove of the gear is less than 1 mm ³ , the discharge amount per unit time is reduced. If the rotation speed of the gear pump is increased and the discharge amount is increased, the gear pump may be damaged due to excessive wear on the gear or excessive force applied to the gear. On the other hand, if it is larger than 60 mm ³ , the discharge amount per unit time increases. If the rotational speed of the gear pump is lowered in order to reduce the discharge amount, pulsation increases, making quantitative extrusion difficult. From the above, by installing a gear pump in which the volume of one groove of the gear is preferably 1 to 60 mm ³ , a small amount of quantitative extrusion can be performed.

  The present inventors investigated the time dependency of the extrusion amount using 20 to 30 g of material, and found that the pressure value by the pressure sensor on the upstream side of the gear pump or the pressure sensor on the downstream side was constant. It was found that quantitative extrusion is possible by suppressing the number of rotations of the screw or the number of rotations of the gear pump. FIG. 1 shows the time dependency of the extrusion discharge amount when a maximum of 25 g of material is charged into the apparatus without considering the pressure upstream of the gear pump. It shows that when the gear pump is operated at a low speed, it can be stably extruded regardless of time. On the other hand, at a rotational speed of 10 rpm or more, the discharge amount decreases remarkably with time, and quantitative extrusion becomes difficult. FIG. 2 shows the time dependency of the extrusion discharge amount when the screw rotation speed is controlled so that the pressure becomes constant at various gear pump rotation speeds. It shows that stable extrusion can be performed with little variation in the extrusion discharge amount with time under the conditions of each rotational speed.

  The inventors installed at least two pressure sensors in the resin reflux path, and optimized the flow path in order to enable measurement of resin viscosity. If a high-viscosity material is used and the flow path is small, there is a concern that the pressure rapidly increases. Considering the pressure resistance of the extruder, gear pump, and pressure sensor, the resin reflux path was designed to be 35 MPa or less, the target material, its grade, and the shear rate to be measured.

Therefore, by connecting a die such as a film, a sheet, a tube or the like to the tip of the extruder for evaluating a resin material of the present invention, a viscosity up to a molding evaluation and a shear rate of about 1000 s ^-1 can be obtained with a sample amount of only 20 to 30 g. It was found that can be evaluated with high accuracy. Furthermore, if at least two extruder tips are connected and a die for co-extrusion is provided, the formability of the multilayer film, sheet and tube can be evaluated quantitatively.

Hereinafter, the present invention will be described in more detail.
Examples of the resin material that can be evaluated according to the present invention include a homogenous system, a blend composed of two or more kinds, and a composite resin containing inorganic particles. A single layer or a multilayer composed of two or more layers can be used. Extruded films, sheets, tubes, etc. can be extruded. Specific examples of thermoplastic resins include polyolefin resins such as polyethylene resins (PE) and polypropylene resins (PP), polyester resins, polyamide resins (PA), polylactic acid, and polybutylene succinate. Biodegradable resin, ethylene-vinyl alcohol copolymer (EVOH), ethylene-vinyl acetate copolymer, polystyrene (PS), polyvinyl chloride, polyvinylidene chloride, acrylonitrile / styrene resin, polyacetal, acrylonitrile / butadiene / styrene resin (ABS), methacrylic resin, polymethylpentene, polycarbonate (PC), modified polyphenylene ether, polyphenylene sulfide, polyether ether ketone, polyether imide, polyarylate, polysulfone, polyether Rufon, polyamideimide, liquid crystal resins, and fluorine resins.

  The polyolefin resin that can be evaluated in the present invention is generally referred to as a polyolefin resin, and specifically, an α-olefin having 2 to 12 carbon atoms such as ethylene, propylene, and 1-butene. These are homopolymers or copolymers. For example, low density polyethylene, medium density polyethylene, high density polyethylene, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene-4-methyl-1-pentene copolymer Ethylene / α-olefin copolymer such as polymer, ethylene / acrylic acid copolymer, ethylene / acrylic acid copolymer such as ethylene / methacrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / acetic acid An ethylene-based (co) polymer such as a vinyl copolymer, an ethylene-α, β-unsaturated carboxylic acid cross-linked product, an ethylene-vinyl ester copolymer such as an ethylene / methacrylate copolymer, and a modified product thereof; Propylenes such as polypropylene, propylene / ethylene copolymer, propylene / 1-butene copolymer ( ) Polymer and a modified product thereof, poly-1-butene, poly-1-hexene, poly-4-methyl-1-pentene.

  Examples of polyester resins that can be evaluated in the present invention include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate, as well as copolymer polyesters, aliphatic polyesters, oxyacids, or intramolecular cyclized products thereof. Examples thereof include polyester resins typified by polymers or modified products thereof.

  Examples of the polyamide-based resin that can be evaluated in the present invention include nylon 6 using ε-caprolactam as a main raw material. Examples of other polyamide resins include polyamide resins obtained by polycondensation of lactams having three or more members, ω-amino acids, dibasic acids and diamines. Specifically, as lactams, in addition to the above-mentioned ε-caprolactam, enantolactam, capryllactam, lauryllactam, and ω-amino acids include 6-aminocaproic acid, 7-aminoheptanoic acid, 9- Examples include aminononanoic acid and 11-aminoundecanoic acid. Dibasic acids include adipic acid, glutaric acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecadioic acid, hexadecadioic acid, eicosandioic acid, eicosadienedioic acid, 2 2,4-trimethyladipic acid, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, and xylylenedicarboxylic acid. Furthermore, as diamines, ethylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, pentamethylenediamine, undecamethylenediamine, 2,2,4 (or 2,4,4) -trimethylhexamethylenediamine, cyclohexane Examples thereof include diamine, bis- (4,4′-aminocyclohexyl) methane, and metaxylylenediamine. A polymer obtained by polycondensation of these or a copolymer thereof, such as nylon 6, 7, 11, 12, 6.6, 6.9, 6.11, 6.12, 6T, 6I, MXD6 (Metaxylene dipanamid 6), 6 / 6.6, 6/12, 6 / 6T, 6 / 6I, 6 / MXD6 and the like.

  The thermoplastic resin that can be evaluated in the present invention may be used in combination of one or more selected from other resins and inorganic fillers. In addition, the thickness of each layer of the thermoplastic resin evaluated in the present invention is not particularly limited and may be appropriately selected depending on the purpose and the like, but the thickness of each layer in a film and a tubular molded product is usually 2 to 1000 μm. Range.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, it cannot be overemphasized that the scope of the present invention is not limited to these Examples.

Apparatus Extruder: ULT nano manufactured by Technobel was used. The diameter of the screw 1 is 15 mm, and the ratio L / D of the length to the screw diameter is 15. As shown in FIG. 3, a 0.6 cc / rev. Zenith gear pump 4 (PEP-II) is installed at the tip of the screw, and pressure sensors 3 and 5 are installed upstream and downstream of the gear pump 4. Yes. Connected to the tip of the gear pump 4 is a switching unit 6 that controls whether to return to the return flow path 7 or to push out to a die (not shown). Specifically, a circulation path composed of a circular pipe flow path with a diameter of 4 mm and a slit flow path with a cross-sectional area of 3.6 mm ² is installed. In this circulation path, a pressure sensor (NP400) 8 made of Dynisco with a diameter of 6 mm. And 9 are installed. A die of a coat hanger type having a width of 20 mm was used. The detected pressure data can be recorded using a data logger NR-500 manufactured by Key Ennis, and converted into a viscosity according to JIS K7199. In addition, although the biaxial screw was shown in FIG. 3, this can be made into a single axis or a polyaxial, and a plunger type thing may be sufficient.

(1) Viscosity measurement Sumitomo Chemical Co., Ltd. polypropylene (PP) with a melt flow rate (JIS K6922-2) of 30, 8, 1 g / min, Sumitomo Chemical with a melt flow rate (JIS K6922-2) of 4 g / min Low density polyethylene (LDPE) manufactured by the company, linear low density polyethylene (LLDPE) manufactured by Sumitomo Chemical Co., Ltd. having a melt flow rate (JIS K6922-2) of 4 g / min, and intrinsic viscosity IV (JIS K7390) Viscosity was measured using 25 g of polyethylene terephthalate (PET) manufactured by Teijin Chemicals Ltd. at 0.74 dL / g.

The sample is put into the extruder, the screw rotation is constant (100 rpm), the rotation speed of the gear pump 4 (10 rpm), and the measurement is started after the pressure gauge in front of the gear pump 4 is stabilized. The pressure of the circulation path is measured when the gear pump 4 is operated every minute from 5 to 35 rpm in increments of 5 rpm. The stress σ is calculated from the average value of the pressure difference at each gear pump rotation speed in the obtained circulation path. The discharge amount Q is determined from the rotational speed of the gear pump, and the apparent shear rate γ ′ _ap is obtained. The true shear rate γ ′ is obtained from the slope of the straight line obtained by plotting the obtained log η _ap / Pa · s on the vertical axis and log (γ ′ _ap / s ⁻¹ ) on the horizontal axis. As a result, as shown in FIG. 4, the shear rate dependence of the true shear viscosity η is required.

In FIG. 4, a white plot indicates viscosity data measured with an existing rheometer (ARES manufactured by TA Instrument, Capillograph manufactured by Toyo Seiki), and a black plot indicates the viscosity measured with the extruder of the invention. As is apparent from the figure, the viscosity in the region up to a shear rate of 1000 s ⁻¹ measured by the extruder of the present invention is in good agreement with the results of existing rheometers.

(2) Evaluation of film formability Polypropylene (PP) manufactured by Sumitomo Chemical Co., Ltd. having a melt flow rate (JIS K6922-2) of 30, 8, 1 g / min, and melt flow rate (JIS K6922-2) of 4 g / min. Sumitomo Chemical Co., Ltd. Low Density Polyethylene (LDPE), Melt Flow Rate (JIS K6922-2) 4g / min Sumitomo Chemical Co., Ltd. Linear Low Density Polyethylene (LLDPE), Intrinsic Viscosity IV (JIS K7390) Of polyethylene terephthalate (PET) manufactured by Teijin Chemicals Ltd. with 0.74 dL / g was used. Film formation was performed using a resin amount of 100 g and changing the take-up roll speed to 2, 4 and 8 rpm when the gear pump rotation speed was 2.5 and 5 rpm. FIG. 5 shows the draft ratio dependence of the film width.

  As is generally known, the film width of a branched polymer does not depend on the draft ratio, but the film width decreases as the draft ratio increases in materials with weak non-Newtonian properties such as LLDPE and PET. To do. This result is consistent with the result of actually forming a film with a conventional large evaluation apparatus, and it can be seen that the actual production molding can be reproduced by the invented apparatus.

As described above, according to the present invention, the thermoplastic resin can accurately measure the viscosity up to a shear rate of 1000 s ⁻¹ with, for example, a resin amount of 20 to 30 g, and at the same time, at the tip of the extruder of the present invention. By attaching the mold, quantitative extrudability can be evaluated, and various physical properties such as mechanical properties of the molded product can be evaluated simultaneously. In addition, the extruder of the present invention has a scaled down configuration of a mounting molding machine, and can be applied to high value-added product development such as coextrusion molding.

DESCRIPTION OF SYMBOLS 1 Screw 2 Sample supply port 3 Pressure gauge 4 Gear pump 5 Pressure gauge 6 Flow path switching valve 7 Circulation path 8 Pressure gauge 9 Pressure gauge

Claims (3)

A resin extruder having a screw part or a plunger part and a gear pump, and capable of selectively extruding resin to a discharge port or a resin reflux path,
The gear pump is provided between the screw part or plunger part and the discharge port,
The resin reflux path is provided so that the flow path switching part provided between the gear pump and the discharge port communicates with the screw part or the plunger part, and at least two pressure sensors are provided, and the internal capacity of the extruder is 100 cc or less. And the volume of one groove of the gear pump is 1-60mm ^Three The resin extruder characterized by being. The resin extruder according to claim 1, wherein a pressure sensor is provided on at least one of the upstream side and the downstream side of the gear pump. The resin extruder according to claim 1 or 2, wherein the resin extruder is used for evaluation of a resin material.

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