JP2007245641A - Analysis method of flow state of themoplastic molten resin in die and die therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an analysis method of flow state and a die therefor capable of evaluating the flow state of the molten resin in the die which has an effect on an appearance, transparency, and mechanical characteristic or the like of extrusion products such as film, sheet, or tube. <P>SOLUTION: When extrusion molding at least one layer flat or cylindrical film or sheet or a cylindrical tube by using at least one kind of thermoplastic resin, flow state of the molten resin in the die is detected by using the extrusion die where a fluorescer is compounded to at least one kind of the thermoplastic resin and an observation door is provided, fluorescent excited from at least one kind of the thermoplastic resin, is detected by using a confocal laser microscope having the maximum speed capable of acquiring an image of 10 frames per second (fps) or more, and the flow state in the die is observed, recorded and analyzed by using a high-speed camera having the maximum photographing speed of 30 frames per second (fps) or more. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for analyzing the flow state of a thermoplastic molten resin in a die and a die for the same, and more specifically, the appearance, transparency, and mechanical properties of an extruded product such as a thermoplastic resin film, sheet and tube. In order to be able to quickly, conveniently and accurately evaluate the flow state of the molten resin in the die that affects the die, etc., a method for providing an observation window in the die for observation, recording and analysis, and a die therefor About.

  Conventionally, various attempts have been made to obtain a desired extruded product by observing the flow state in an extruder and improving the flow state in the extruder for extrusion molding of a thermoplastic resin. For example, in Patent Document 1, when a mixture of a resin melt and a foaming agent is extruded, an observation window is provided in the middle of the extruder to observe the foaming start position. In Patent Document 2, when extruding a resin melt, a technique for providing a colorimetric window and a colorimetric optical fiber cable connected to the die of an extruder to monitor changes in the color value of the extruded resin every moment is reported. ing. However, these methods cannot measure, record, and analyze the flow state in the die that affects the appearance, transparency, and mechanical properties of the extruded product. Further, it is apparent that the above method cannot provide information on domain deformation in an incompatible polymer blend composed of two or more resins and behavior at an interface in a multilayer resin extrudate.

JP 2002-11774 A JP-A-5-318560

  Therefore, the object of the present invention is to quickly, easily and accurately determine the flow state of the molten resin in the die that affects the appearance, transparency, mechanical properties, etc. of extruded products such as thermoplastic resin films, sheets and tubes. Therefore, it is an object of the present invention to provide a method for enabling observation and recording of a flow state in a die and analysis thereof, and a die for the same.

  According to the present invention, when extruding at least one planar or cylindrical film or sheet or cylindrical tube using at least one thermoplastic resin, a fluorescent agent is blended with at least one thermoplastic resin. In addition, using an extrusion die provided with an observation window, the flow state of the molten resin in the die is determined by using a confocal laser microscope having a maximum image acquisition speed of 10 frames per second (fps) or more. Provided is a method for analyzing the flow state in a die that detects fluorescence excited from the light and can be observed, recorded and analyzed using a high-speed camera with a maximum imaging speed of 30 frames per second (fps) or more. .

  According to the present invention, when extruding at least one planar or cylindrical film or sheet or cylindrical tube using at least one thermoplastic resin, a fluorescent agent is blended with at least one thermoplastic resin. And using an extrusion die provided with an observation window, the flow state of the molten resin in the die is determined using a confocal laser microscope having a maximum image acquisition speed of 10 frames per second (fps) or more. There is provided an extrusion die that detects fluorescence excited from one kind, and can be observed, recorded and analyzed using a high-speed camera having a maximum photographing speed of 30 frames per second (fps) or more.

  According to the present invention, flow in a die that affects the appearance, transparency, mechanical properties, etc. of an extruded product of a thermoplastic resin (film, sheet, tube, etc., particularly laminated film, laminated sheet, laminated tube, etc.). By observing and recording the state from the flow observation window provided on the extrusion die, the flow state of the molded product can be evaluated (or analyzed) quickly, simply and accurately.

  As a result of researches to solve the above-mentioned problems, the present inventors have provided a flow observation window on a thermoplastic resin extrusion die, and blended a fluorescent agent with at least one of the thermoplastic resins to be used. Extrusion, irradiation of laser light from the observation window, excitation of the fluorescent agent, emission of fluorescence, observation and recording of it, appearance of extruded products such as thermoplastic resin films, sheets, tubes, etc., transparent It has been found that the flow state of the molten resin in the die that affects the properties, mechanical properties, etc. can be evaluated (analyzed) quickly, simply and accurately.

  The thermoplastic resin that can be used to analyze the flow state in the die by the method of the present invention includes a homogeneous system, a blend of two or more resins, and a composite containing inorganic particles. From this, a single layer or two or more multilayer extruded films, sheets, tubes and the like can be extruded. Specific examples of the thermoplastic resin are as follows. Polyolefin resins such as polyethylene resins (PE) and polypropylene resins (PP), polyester resins, polyamide resins (PA), biodegradable resins such as polylactic acid and polybutylene succinate, ethylene-vinyl alcohol copolymer 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 resin (PC), modified polyphenylene ether, polyphenylene sulfide, polyetheretherketone, polyetherimide, polyarylate, polysulfone, polyethersulfone, polyamideimide Liquid crystal resins, and fluorine resins. The most common type of combination of layers is PP / PP, PC / polymethyl methacrylate resin (PMMA), PC / PC, PMMA / ABS, polyethylene terephthalate resin (PET) if it is 2 types and 2 layers. / PET, general-purpose polystyrene (GPPS) / impact-resistant polystyrene resin (HIPS). If it is 2 types and 3 layers, it is PE / EVOH / PE. For example, PA / EVOH / PE for 3 types and 3 layers, and PET / PA / EVOH / PE for 4 types and 4 layers may be mentioned.

  The polyolefin resin constituting the present invention is generally called a polyolefin resin, and is a homopolymer or copolymer of an α-olefin having 2 to 12 carbon atoms such as ethylene, propylene, and 1-butene. Indicates. 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 Ethylene / α-olefin copolymers such as copolymers, ethylene / acrylic acid copolymers, ethylene / acrylic acid copolymers such as ethylene / methacrylic acid copolymers, ethylene / acrylic acid ester copolymers, ethylene Ethylene-based (co) polymers such as vinyl acetate copolymers, ethylene-α, β unsaturated carboxylic acid ion cross-linked products, ethylene-vinyl ester copolymers such as ethylene / methacrylic acid ester copolymers, and modified products thereof , Polypropylene, propylene-ethylene copolymer, propylene-based copolymers such as propylene / 1-butene copolymer Polymer and a modified product thereof, poly-1-butene, poly-1-hexene, poly-4-methyl-1-pentene.

  Examples of the polyester resin used in the present invention include polyethylene terephthalate, polytrimethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, and the like, as well as a copolymer polyester, aliphatic polyester, oxyacid, or an intramolecular cyclized polymer thereof. The polyester resin represented by these or its modified body etc. are mentioned.

  Examples of the polyamide-based resin used 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) -tolmethylhexamethylenediamine, Examples include cyclohexanediamine, 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.

  These thermoplastic resins used in the present invention may be used alone or in combination of two or more selected from other resins and inorganic fillers. Further, the thickness of each layer of the thermoplastic resin used 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 the film, sheet and tube-shaped molded product is usually 10 to 10. The range is 1000 μm.

  The flow observation window provided in the extrusion die according to the present invention can be manufactured from a material having pressure resistance, heat resistance, high strength, light transmittance, and the like, specifically, quartz, sapphire, Pyrex (registered trademark) tempered glass. Vycor (registered trademark) tempered glass can be used. There are no particular limitations on the shape, size, and mounting position of the observation window according to the present invention, but a circular shape, a rectangular shape, an elliptical shape, each having a size of about 0.5 to 5 cm in the extrusion direction of the extrusion die. It is preferable to provide on parallel surfaces (surfaces perpendicular to the thickness direction of extruded films, sheets, tubes, etc.). The glass thickness of the glass window depends on the pressure and the shape of the opening. For example, if the thickness is the same as the width of the opening, a breakdown voltage of about 10 MPa is usually obtained.

The present invention will be further described below with reference to the drawings.
FIG. 1 is a schematic diagram showing an example of an extrusion die 1 of the present invention and an observation window 2 provided thereon. In the embodiment of FIG. 1, a three-layer laminated film 4 made of two types of polymers A and B (thermoplastic resin) is shown. In this case, the polymer A in the center contains a fluorescent agent, and the observation window 2 is irradiated through the objective lens 3 in the confocal laser microscope to irradiate the fluorescent agent in the die. The excitation fluorescence from the fluid molten resin layer containing is photographed with a high-speed camera through the objective lens 3.

  FIG. 2 shows an example of a configuration in which an extrusion die (film die) 1 provided with an observation window 2 according to the present invention is attached to two extruders 5 to extrude two or more extruded films (laminated film) 4. Is. Reference numeral 6 denotes an adapter for merging a plurality of resins before the entrance of the die.

  In the present invention, as a fluorescent agent that can be used by blending in a desired thermoplastic resin, any fluorescent agent capable of exciting fluorescence by irradiation with laser light at the extrusion temperature of the thermoplastic resin can be used. Preferably, it is heat resistant and has good dispersibility in the resin. Specifically, naphthalimide, thioxanthene fluorescent dye, coumarin fluorescent dye, perylene fluorescent dye, methine fluorescent dye, benzopyran fluorescent dye having heat resistance of 200 to 300 ° C. which is a general processing temperature of resin Dyes, thioindigo fluorescent dyes, anthraquinone fluorescent dyes and the like are preferable.

  Specific examples of thioxanthene fluorescent dyes include CI Solvent Yellow 98 and the like, and specific examples of coumarin fluorescent dyes include CI Solvent Yellow 160: 1, Macrolex Fluorescent Red G (manufactured by Bayer) and Kayase Yellow SF-G ( Specific examples of perylene-based fluorescent dyes such as CI Vat Red 15, CI Vat Orange 7, CI Solvent Yellow 5, Lumogen F Yellow 083 (manufactured by BASF) and Lumogen Specific examples of methine fluorescent dyes such as F Red 305 (manufactured by BASF) include CI Disperse Yellow 82 and the like, such as benzopyran fluorescent dyes. Examples of thioindigo fluorescent dyes such as Kayset Red SF-B (manufactured by Nippon Kayaku Co., Ltd.) include CI Vat Red 1, CI Vat Red 2, and CI Vat Red 41, anthraquinone fluorescent dyes Specific examples of the CI include CI Solvent Red 150, CI Solvent Red 197, and CI Solvent Red 150. Although there is no restriction | limiting in particular in the compounding quantity of a fluorescent agent, It is preferable that it is 0.01-5 weight% on the basis of the weight with respect to a thermoplastic resin, and it is still more preferable that it is 0.05-1 weight%.

  The confocal laser microscope used in the present invention can detect fluorescence excited by a fluorescent agent contained in a substance by color, for example, so that various morphological analyzes (mainly cell division, signal transduction, Real-time observation of vesicle transport, microtubule dynamics, microcirculation, etc.) In the present invention, a film (or sheet) of a flowing thermoplastic resin passing through an extrusion die by irradiating a laser beam having a certain wavelength (wavelength region from the ultraviolet region to the near infrared region) from an observation window provided on the extrusion die. The slip phenomenon on the wall surface of the tube) or the separation flow between the multilayer resins can be observed. That is, the surface of the thermoplastic resin layer, the inner surface, the interface, the die wall surface is excited by the excitation of the fluorescence in the wavelength region from the ultraviolet region to the near infrared region by previously blending the fluorescent agent into the target thermoplastic resin. The fluorescence from the die exit can be visualized as a three-dimensional distribution to construct an image. The method of blending the fluorescent agent is not particularly limited, and examples thereof include a method of blending by dissolving together with a resin in a solvent, a method of blending in an extruder, or a method of chemically bonding.

  An example of the configuration of a confocal laser microscope that can be used in the present invention will be described below with reference to FIG. That is, in the confocal laser microscope having the structure shown in FIG. 3, the laser beam passes through the first pinhole and is irradiated from the observation window of the die onto the sample surface (for example, a multilayer film (sheet) flowing in the die). Light (fluorescence) from the observation plane, ie, the focal plane, of the target extruded film (sheet) interface is guided to the second pinhole, the focused light passes through the second pinhole, and the unfocused light is Blocked. Only light that has passed through the second pinhole is extracted and imaged. As described above, in the present invention, laser light is incident on a sample, fluorescence excited by a fluorescent agent in the sample is swept (scanned) with a confocal scanner, and this is observed and recorded with a high-speed camera, so that melting during flow is achieved. High-speed images of the resin inner surface, surface, interface, etc. can be directly observed and recorded, and only focused images are imaged and recorded. Furthermore, the state in the depth direction can be observed by shifting the in-focus position at a high speed such as above and below the lens.

  There is no example of observing the state of the thermoplastic resin flowing in the die using a confocal laser microscope. Unlike a conventional microscope, a confocal laser microscope that can be used in the present invention can observe a very small spot of a sample. This spot must be scanned to construct the image. There are two scanning methods at this time: a multi-beam method called a Nipou method, which uses a rotating disk with a large number of pinholes, and a carbano mirror method that scans a single laser beam with a galvanometer mirror. The former method is more preferable for observation. Although the maximum image acquisition speed depends on the flow state, in view of the resin flow in the extruder, it is 10 frames per second (fps) or more, preferably 100 fps or more, more preferably 300 fps or more. As the confocal laser microscope, for example, Yokogawa CSU22 can be used.

  In general, confocal laser microscope applications have been used for real-time observation of cell division, signal transduction, vesicle transport, microtubule dynamics, microcirculation, and the like in the life science field. This is because, as described above, a minute region can be seen clearly with high sensitivity, and a 3D image can be constructed from an image in the thickness direction of the sample by moving the sample table up and down. This method contributed greatly to the progress of the field of biology in particular. However, there are very few examples of applying the confocal microscope to the visualization of the process in the engineering field, and there has been no example focusing on the state analysis of the thermoplastic resin flowing at high speed in the die. The inventor installs a confocal laser microscope in the visualization window of the die of the extruder, and observes a slip phenomenon on the wall surface of a single layer or two or more types of thermoplastic resins, or a separation flow between multilayer resins. For analysis, we have found that a confocal laser microscope and a piezo actuator are used to move the optical system up and down at high speed and to use a fluorescent agent with appropriate heat resistance and dispersibility.

  In the present invention, the excitation fluorescence observed using a confocal laser microscope from the observation window provided on the extrusion die has a maximum photographing speed of 30 frames per second (fps) or more, preferably 100 fps or more, more preferably 500 fps or more. Use to record. Such a high-speed camera requires a large maximum imaging speed in order to observe a flowing sample with a high-speed, high-resolution confocal microscope system, and a high-sensitivity, high-resolution camera to capture a weak fluorescent image from the sample. Need. Specifically, it is preferable to have a binning function for increasing scanner sensitivity and reducing noise because the maximum number of pixels to be captured is 256 × 256 pixels or more and it is necessary to capture a weak fluorescent image. For example, MotionPro HS-4 manufactured by Redlake can be used.

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

Example 1 and Comparative Example 1
Apparatus and conditions (1) Confocal scanner: A high-speed confocal scanner CSU22 of Yipagawa Electric Co., Ltd. using a Nipo disk scanning system with microlenses was used. For image observation, a large number of laser beams formed on the focal plane by incident light pinholes are subjected to multi-scanning on this focal plane (XY axis) to obtain one image, and this scan is performed by a piezo actuator using a Z-axis. The scanning was performed in the axial direction (die thickness direction). As the light source, a laser having a wavelength of 532 nm and an output of 200 mW was used. An inverted microscope was used, and an objective lens having a magnification of 20 times was used.

  (2) Image intensifier: The intensity of fluorescence emitted from the sample is weak. Furthermore, in the case of high-speed photography, since the exposure time is shortened, the intensity of fluorescence is further weakened, so that it is difficult to acquire an image with high sensitivity. For this purpose, an electronic image was amplified using C8600-03 (image intensifier) manufactured by Hamamatsu Photonics.

  (3) In order to take a moving image at a high speed, a MotionPro HS-4 manufactured by a high speed CCD camera Redlake was used.

  (4) The twin-screw co-directional extruder (KZW-15) manufactured by Technobel was used as the extruder. The screw diameter is 15 mm, and the ratio L / D of the length to the screw diameter is 45. Multi-layer films and sheets are two types and three layers by using two extruders to provide an adapter that merges multiple resins in front of the die, and then laminating and extruding and extruding with a single-layer die manifold. The resin can be extruded. The die used was a coat hanger type. In addition, the die has a visualization window made of heat-resistant glass, packing, and metal fittings. A confocal laser microscope system consisting of an objective lens, confocal scanner, image intensifier, high-speed camera, etc. installed here The flow state of the resin can be observed. The die is temperature-controlled using a band heater, and the pressure change inside the die can be monitored with a pressure gauge.

Example 1: Observation of flow state between layers of PS / LDPE / PS film by confocal laser microscope Low density polyethylene (LDPE) manufactured by Nippon Polyethylene Co., Ltd. having a melt flow rate (JIS K6922-2) of 7.0 g / 10 min LC600A (Novatech LD) is used in a first extruder having a barrel temperature of 200 ° C., and polystyrene (PS) SGP10 (PS J-polystyrene) manufactured by PS Japan Co., Ltd. having a melt flow rate (ISO 1133) of 1.9 g / 10 min. The mixture was put into a second extruder having a barrel temperature of 200 ° C., plasticized and kneaded, and extruded from a die. As the fluorescent agent, perylene (Lumogen F Orange 240, manufactured by BSF) having a maximum absorption wavelength of about 525 nm and a maximum emission wavelength of about 571 nm was used, and a resin sample previously mixed with polystyrene by 1 wt% was used. In the film structure, the center layer is LDPE and the skin layers on both sides are PS. The extruded resin molded product was subjected to structural analysis using the confocal laser microscope. Without moving the focal plane in the Z-axis (thickness) direction, the same XY plane is scanned simultaneously with 1000 laser beams. I got a statue. Next, the focal plane was moved in the Z-axis (thickness) direction by a piezoelectric actuator, and the same observation was performed. These observation results are schematically shown in FIG.

Comparative Example 1: Observation of fluid state between layers of PS / LDPE / PS film with a stereomicroscope Extruding a thermoplastic resin in Example 1 using a stereomicroscope SZ61 (Olympus, biological microscope) instead of a confocal laser microscope Things were observed. The light source is a halogen lamp illumination as in normal microscope observation. However, the disturbance of the interface between the laminated resins as seen in Example 1 could not be observed. In other words, the conventional optical microscope observation does not allow the structural analysis during flow of the laminated resin, which was possible in Example 1.

  According to the present invention, the flow observation window provided on the extrusion die and the confocal laser microscope system enable slip, separation flow at the laminated film interface, slip on the resin and wall surface, separation flow, and dispersion layer in the incompatible blend. Deformation behavior can be observed, so it is possible to accurately analyze the occurrence conditions of defective phenomena when molding thermoplastic resins, or even if a minute defective phenomenon actually occurs in a molded product It can correspond to.

It is a schematic diagram which shows an example of the die | dye for film extrusion observation which concerns on this invention. It is the schematic diagram which combined the extruder with the die for film extrusion observation which concerns on this invention. It is drawing which shows typically the observation method by the confocal laser microscope used in this invention. 2 is a drawing schematically showing the observation results of Example 1. FIG.

Explanation of symbols

A 1st thermoplastic resin (containing fluorescent agent)
B Second thermoplastic resin 1 Extrusion die 2 Observation window 3 Objective lens 4 Laminated film 5 Extruder 6 Adapter

Claims (3)

  When extruding at least one planar or cylindrical film or sheet or cylindrical tube using at least one thermoplastic resin, a fluorescent agent is blended with at least one thermoplastic resin and an observation window is provided. Using an extrusion die, the flow state of the molten resin in the die is measured with fluorescence excited by at least one thermoplastic resin using a confocal laser microscope with a maximum image acquisition speed of 10 frames per second (fps) or more. A method for analyzing the flow state in a die that can be detected and analyzed using a high-speed camera with a maximum shooting speed of 30 frames per second (fps) or higher.   The fluorescent agent is at least one selected from naphthalimide, thioxanthene fluorescent dye, coumarin fluorescent dye, perylene fluorescent dye, methine fluorescent dye, benzopyran fluorescent dye, thioindigo fluorescent dye and anthraquinone fluorescent dye The method according to claim 1, wherein the method is a fluorescent agent.   When extruding at least one planar or cylindrical film or sheet or cylindrical tube using at least one thermoplastic resin, a fluorescent agent is blended with at least one thermoplastic resin and an observation window is provided. Using an extrusion die, the flow state of the molten resin in the die is measured with fluorescence excited by at least one thermoplastic resin using a confocal laser microscope with a maximum image acquisition speed of 10 frames per second (fps) or more. An extrusion die that can be detected and analyzed using a high-speed camera with a maximum shooting speed of 30 frames per second (fps) or higher.

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