JP2004276539A - Apparatus for producing pellets of thermoplastic polymer blend having surface tackiness - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable pelletizing of a thermoplastic polymer blend having tackiness such as a hot melt adhesive by performing a mold releasing treatment on pellet surfaces. <P>SOLUTION: The disclosed pelletizing apparatus for the thermoplastic polymer blend comprises: a kneading machine for kneading the polymer blend having surface tackiness in a melted state; a dividing device for dividing the melted polymer blend extruded from the kneading machine in a desired shape; a cooling/conveying device for cooling the desirably shaped divided bodies in a fluid and conveying while pelletizing in an approximately spherical form utilizing surface tension; a mold release agent application device for forcibly passing the obtained pellets through the inside of a flow such as turbulence of a release agent emulsion kept at a nearly normal temperature to coat the surface of pellets with the emulsion; and a drying device for conveying the pellets while drying the water contained in the mold release agent on the surface of the pellets while vibrating by a vibration dryer. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a mixture containing a thermoplastic elastomer or a synthetic rubber such as SIS or SBS and a tackifier resin and a plasticizer such as an oil, or a mixture containing a thermoplastic elastomer or a synthetic rubber and a tackifier resin, or a thermoplastic resin. The present invention relates to an apparatus for producing pellets of a thermoplastic polymer mixture having a surface tackiness, which comprises a mixture containing an elastomer or a synthetic rubber and a plasticizer such as oil.
That is, (1) a part of the components of the synthetic rubber-based hot melt adhesive is kneaded and pelletized for the purpose of being used as a master batch, or (2) the surface of the hot melt thermoplastic polymer having a tack on the surface is treated. The present invention relates to a manufacturing apparatus for pelletizing by heating.
[0002]
[Prior art]
As a method of pelletizing the adhesive hot melt adhesive, there is a method of coating the adhesive in a molten state with another resin having low tackiness (for example, see Patent Document 1).
[0003]
[Patent Document 1]
Japanese Patent Publication No. 2000-502120 (Claims)
[0004]
[Problems to be solved by the invention]
However, in this method, since both the adhesive and the coating agent are in a fluid state (molten state) at the time of coating, it is difficult to apply a uniform surface coating. Requires very expensive equipment and subtle adjustments.
In general, hot melt adhesives are prepared by adding tackifying resins such as rosin and petroleum resin to base polymers such as thermoplastic elastomers, synthetic rubbers and EVA, and further adding additives such as waxes, plasticizers and antioxidants. Manufacturing.
Of these synthetic rubber-based hot melt adhesives, that is, hot melt adhesives, particularly those whose base polymer uses a high melt viscosity such as a thermoplastic elastomer, are difficult to produce with a normal heating and stirring kettle. Generally, it is manufactured by a kneader such as a kneader or an extruder, which is more expensive than a general heating and stirring kettle.
[0005]
If a base polymer such as a thermoplastic elastomer that requires a kneading machine, such as a rosin-based resin, a terpene-based resin, a petroleum resin, and a tackifying resin such as a phenolic resin, is preliminarily blended into a masterbatch, Since the apparent melt viscosity is reduced, if such a master batch is used, a hot melt adhesive can be easily mixed with other raw materials such as a wax, a plasticizer, and other additives even in a general heating and stirring vessel. It is possible.
[0006]
However, when the thermoplastic elastomer and tackifying resin are blended in a molten state, the resulting product generally has tackiness on the surface, making it difficult to pelletize it. It has to be filled and cooled.
[0007]
When a masterbatch of such a block is used, an enormous amount of time is required until it is melted when charged into a heating and melting pot, depending on its size, and is not suitable as a masterbatch.
[0008]
Conventionally, since the adhesive type hot melt adhesive has surface tackiness, it is filled and packaged in a container which is releasable from an adhesive such as paper or resin whose surface is release-treated. Furthermore, in such a small container, the adhesive type hot melt adhesive is integrated (one block), and it is difficult to divide the adhesive at the time of use. Due to restrictions on the size of the machine at the time (such as a melting pot of a coating machine) and handling problems, the size of one block is usually about 2 to 3 kg or less. These containers are then disposed of as waste after use of the adhesive.
[0009]
The present invention has been made in view of the above points, and when manufacturing a hot melt adhesive or the like, provides a device that enables pelletization despite having tackiness by releasing the surface. The purpose is to do. In addition, users can easily mix materials with wax, other plasticizers, other additives, and other raw materials in a general heated stirrer as a masterbatch of the base polymer and mix the materials according to various applications such as hot melt adhesives. It is an object of the present invention to provide a thermoplastic polymer pellet producing apparatus having surface tackiness, which can be produced.
[0010]
[Means for Solving the Problems]
The apparatus for producing pellets of a thermoplastic polymer mixture having a surface tackiness according to the present invention is a mixture containing a thermoplastic elastomer or a synthetic rubber, a tackifier resin and a plasticizer such as oil, or a mixture of a thermoplastic elastomer or a synthetic rubber and an adhesive. A kneader or an extruder for mixing a thermoplastic polymer mixture having a surface tackiness in a molten state, such as a mixture containing an imparting resin, or a mixture containing a thermoplastic elastomer or a synthetic rubber and a plasticizer such as oil. A kneading machine, a dividing device for dividing the molten thermoplastic polymer extruded from the kneading machine into a desired shape, and a substantially spherical particle utilizing surface tension while cooling the divided desired shape in a fluid. A cooling / transporting device that transports the pellets while forming them into pellets, and a release agent emulsion that keeps the substantially spherical particles near room temperature. Is forcibly passed through a flow that forms a turbulent flow, and a release agent application device that applies a release agent emulsion to the surface of the pellets, and a moisture contained in the release agent on the surface of the pellets is shaken by a vibration dryer. A drying device for conveying while vibrating and drying.
[0011]
In the apparatus for producing a thermoplastic polymer pellet having surface tackiness according to the present invention, when the release agent coating device is a mold release agent emulsion flowing in a circular tube flow, Reynolds number Re ≧ 2100, or When the release agent emulsion flows through the open channel, Re ≧ 1000.
[0012]
In the apparatus for producing a thermoplastic polymer pellet having a surface tackiness according to the present invention, the release agent coating apparatus is characterized in that the release agent emulsion has an uneven flow or an irregular shape due to a bottom surface uneven shape and / or a side uneven shape or a wave-making device. It is characterized in that it is a coating device that can flow.
[0013]
In the apparatus for producing pellets of a thermoplastic polymer having surface tackiness according to the present invention, the release agent application device is an application device in which the release agent emulsion intentionally generates a turbulent flow by a stirrer or the like. It is characterized by the following.
[0014]
In the apparatus for producing a thermoplastic polymer pellet having surface tackiness according to the present invention, the vibration dryer for dehydrating the water of the applied release agent emulsion has a vibration frequency of 120 vpm or more, or an amplitude of 2 mm or more and 100 mm or less. Or the vibration angle is not less than 1 degree and less than 90 degrees.
[0015]
In the apparatus for producing pellets of a thermoplastic polymer having surface tackiness according to the present invention, the vibration dryer has a structure in which drying air heated to 20 ° C. or more blows up air from holes in the vibration surface. And
[0016]
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
1 is a method in which a thermoplastic elastomer or a synthetic rubber and a tackifying resin are mixed or a thermoplastic elastomer or a synthetic rubber and a plasticizer such as an oil, and other raw materials such as WAX are kneaded or extruded in a molten state. This is a dividing device that divides into desired shapes such as granules after mixing with a kneader such as a kneader. The masterbatch is kneaded in a molten state with a kneader such as a kneader or an extruder, or the temperature is adjusted to a predetermined temperature, for example, 70 to 180 ° C. by a temperature controller 1-a while kneading. A kneaded adhesive such as a hot-melt adhesive in a molten state that has been heated and stirred and mixed at a predetermined temperature is extruded from a die at the end of a cylinder, and the extruded kneaded adhesive such as a hot-melt adhesive is poured into running water. This is performed by the portion 1-b which divides the kneaded adhesive material such as a hot melt adhesive by a set underwater cutting machine or the like. Thermoplastic elastomers, synthetic rubbers such as SIS and SBS, EVA and other rubbery elastic polymers are used as the base polymer, and petroleum resins, phenolic resins, rosin and the like are used as the tackifying resin. In addition, various raw materials, such as a plasticizer and a wax, to be blended for the final success or failure are used.
[0017]
As a means for dividing the kneaded adhesive material such as a hot melt adhesive, in addition to the case of cutting with an underwater cutting machine as in this example, any method such as a manual cock, an ON / OF valve, a plunger pump, etc. may be used. In short, it is only necessary that the kneaded adhesive material whose temperature is adjusted can be divided.
The kneaded adhesive such as a hot melt adhesive divided in the fluid undergoes thermal shrinkage by the cooling medium, and substantially spherical particles (several mm to several cm in diameter) are formed by surface tension. The shape of the kneaded adhesive material such as the divided hot melt adhesive may be in various forms such as the above-mentioned spherical pellets, slats, chickens, blocks, cakes, etc. If there is an end portion or the like, it is difficult for the release agent to adhere to the corner portion or the like and blocking occurs, so that spherical pellets are the most preferable shape.
[0018]
Reference numeral 2 denotes a cooling / transporting device that transports a kneaded adhesive such as a hot-melt adhesive having a substantially spherical particle shape while cooling it in a fluid. The divided kneaded adhesive such as hot melt adhesive having substantially spherical particles is conveyed in one direction through a pipe 2-a through which a cooling liquid such as water circulates, and is inclined obliquely downward in the middle of the pipe 2-a. The conveyer medium (cooling medium) also serving as cooling and the substantially spherical hot-melt kneaded pressure-sensitive adhesive are separated by the vibrating sieve 2-b thus provided, and the substantially spherical hot-melt adhesive such as hot-melt adhesive is separated. Only the product is sent to the next step from the right outlet shown in the figure. The transport medium separated by the vibrating sieve 2-b circulates in the pipe 2-a via the pump 2-d. By passing through the cooling device 2-c in the middle of the pipe 2-a, the temperature of the transport medium is prevented from rising due to the heat of the kneaded adhesive such as hot melt adhesive. In addition, in this example, water is used as a transport medium, and a sufficient release agent is used to prevent adhesion of the kneaded adhesives such as the inner wall of the pipe and the divided hot-melt adhesive which is divided into pellets during the transport. Mixed.
[0019]
If a conveying device for kneaded adhesive such as hot melt adhesive is not particularly required between the dividing device 1 for dividing into pellets and the release agent applying device 3 in the next step, the conveying portion is obliquely downward. The pellets may be freely dropped into the atmosphere from the tip of the inclined vibrating sieve 2-b.
[0020]
3 is an example of an apparatus for applying a release agent for a kneaded adhesive such as a hot melt adhesive. The kneaded adhesive such as hot melt adhesive put into the liquid tank 3-a filled with the emulsion of the release agent by polyethylene wax or the like is completely cooled to room temperature while adsorbing the release agent on the surface. . The kneaded adhesive such as hot melt adhesive carried to the discharge side according to the liquid flow in the liquid tank 3-a is sent to the drying device.
The release agent emulsion overflowing from the liquid tank 3-a is temporarily stored in the weir 3-b together with the water recovered from a part of the drying device, and then is transferred to the liquid tank 3-a via the circulation pump 3-c. Return. The reason why the stirring wing 3-d or the like driven by the motor M is provided in the liquid tank 3-a to forcibly generate a vortex in the release agent emulsion is that pellets having a small specific gravity and less than 1 are used. The emphasis is on whether the resin is immersed in the release agent emulsion for a long time. As a result, it is effective in that the release agent can be uniformly applied to the surface of the pellet.
In the present invention, the invention is not necessarily limited to the stirring blade, and it is sufficient that a turbulent flow, an unequal flow, and an irregular flow are obtained. The point is that the solid fine particles of the emulsion type release agent may be adsorbed on the entire surface of the pellet.
[0021]
The Reynolds number Re ≧ 2100 when the release agent emulsion flows in the circular tube flow, or Re ≧ 1000 when the release agent emulsion flows in the open channel.
Further, a coating device may be used in which the release agent emulsion has an uneven flow or an irregular flow due to the uneven shape on the bottom surface and / or the uneven shape on the side surface or a wave-making device.
[0022]
Numeral 4 denotes a drying apparatus. The mold release agent is applied while cooling the pellets and other desired shapes to a room temperature state by the kneaded adhesive material release agent application device 3. Since the release agent is an emulsion, water adheres to the surface of the pellets in addition to the solid fine particle component of the emulsion, and this water is removed by the drying apparatus 4.
A vibration dryer for dehydrating the moisture of a release agent emulsion applied to the entire surface of a kneaded adhesive such as a hot melt adhesive has a vibration frequency of 120 vpm or more, an amplitude of 2 mm to 100 mm or less, and a vibration angle of 1 degree or more and less than 90 degrees. By doing so, water adheres to the surface of the pellets in addition to the solid fine particle component of the emulsion, but the water can be effectively removed.
[0023]
4-a is a vibrating sieve or a vibrating conveyor, which conveys to the next drying step in a state in which the solid fine particle component of the emulsion and the moisture adhere to the surface of the pellet. The moisture on the surface of the kneaded adhesive such as a hot melt adhesive is removed to about 2 to 3%. The water removed here is collected by the weir 3-b. 4-b is a vibrating sieve or a vibrating conveyor. In order to remove moisture on the surface of the kneaded adhesive such as hot melt adhesive to 0.5% or less, the kneaded adhesive is dried by a fan 4-c with an air dryer. It is blowing air control. Further, the vibration dryer has a structure in which drying air heated to 20 ° C. or higher is blown up from the holes of the vibration surface, so that moisture attached to the surface of the pellet can be effectively removed.
It is desirable that the temperature of the air is about 50 ° C. or less and the temperature is as high as possible for drying. The drying device 4 has a built-in heater 4-c.
The temperature of the air for actually drying is determined by the properties of the kneaded adhesive material to be formed.
[0024]
5 is an example of a solid antiblocking agent spraying device. In the present invention, the above drying device is sufficient. However, kneaded adhesives such as hot-melt adhesives with low elastic modulus (easily deformable) such as the above-mentioned emulsion-type release agents alone are not sufficient, preventing blocking during deformation due to their own weight after packing and filling. For this purpose, it is desirable to fill together with a solid release agent such as a wax powder. 6 is a product filling device.
[0025]
【The invention's effect】
The apparatus for producing pellets of thermoplastic polymer having surface tackiness according to the present invention is a mixture containing a thermoplastic elastomer or synthetic rubber, a tackifier resin and a plasticizer such as oil, or a thermoplastic elastomer or synthetic rubber and tackifier. Such as a kneader or an extruder for mixing a thermoplastic polymer mixture having a surface tackiness comprising a mixture containing a resin, or a mixture containing a thermoplastic elastomer or a synthetic rubber and a plasticizer such as an oil in a molten state. A kneading machine, a dividing device for dividing the molten thermoplastic polymer extruded from the kneading machine into a desired shape, and a substantially spherical particle using surface tension while cooling the divided desired shape in a fluid. A cooling / transporting device that transports the pellets while forming them into pellets, and a release agent emulsion that keeps the substantially spherical particles near room temperature are disturbed. A release agent coating device for forcibly passing through the flow forming the release agent, and applying the solid particles of the release agent emulsion to the surface of the pellets so as to be adsorbed thereon; and the water contained in the release agent adsorbed on the surface of the pellets. Since it consists of a drying device that conveys while drying with a vibration dryer, it is possible to use all or part of the pellets of the synthetic rubber-based hot melt adhesive as a master batch, or as a component of the synthetic rubber-based hot melt adhesive. A part can be kneaded and pelletized for the purpose of using it as a masterbatch, and products and raw materials for various applications such as processing and pelletizing the surface of hot melt thermoplastic polymer with tack on the surface it can.
[0026]
In addition, the substantially spherical particles have no corners, have a minimum surface area per unit weight, and have a minimum contact area between other pellets, so that blocking is further eliminated. It works.
[0027]
In the present invention, when the release agent emulsion flows in a circular pipe flow, the Reynolds number Re ≧ 2100, or when the release agent emulsion flows in an open channel, Re ≧ 1000, the turbulent flow is reduced. It will be obtained effectively.
In addition, by using a coating device in which the release agent emulsion becomes uneven or irregular due to the uneven shape of the bottom surface or a wave-making device, turbulence can be easily formed, and turbulence can be effectively obtained.
[0028]
The vibration dryer for dehydrating the water of the release agent emulsion applied to the entire surface of the hot melt kneaded adhesive has a vibration frequency of 120 vpm or more, a swing width of 2 mm to 100 mm or less, and a vibration angle of 1 degree. By setting the angle to be less than 90 degrees, it is possible to prevent the pellets from sticking to each other or to adhere to the device while transporting them while drying.
[Brief description of the drawings]
FIG. 1 is a schematic explanatory view of an apparatus for producing pellets of a thermoplastic polymer mixture having surface tackiness, showing one embodiment of the present invention.
FIG. 2 is a specific explanatory view of an apparatus for producing pellets of a thermoplastic polymer mixture having surface tackiness according to the present invention.
FIG. 3 is a side view showing a portion where a turbulent flow is formed in the release agent applying device according to the present invention.
FIG. 4 is a plan view of FIG. 3;
FIG. 5 is a sectional view taken along line AA of FIG. 3;
FIG. 6 is a right side view of FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Separation apparatus 1 of kneaded adhesive material 1-a Temperature controller 1-b Part which divides kneaded adhesive material 2 Cooling / conveying device 2-a Pipe 2-b Vibrating sieve 2-c Cooling device 2-d Pump 3 Release agent Coating device 3-a Liquid tank 3-b Weir 3-c Circulation pump 3-d Stirrer blade 4 Drying device 4-a Vibrating sieve or vibrating conveyor 4-b Vibrating sieve or vibrating conveyor 5 Solid antiblocking agent spraying device 6 Product filling apparatus

Claims (6)

A mixture containing a thermoplastic elastomer or a synthetic rubber and a tackifier resin and a plasticizer such as an oil, or a mixture containing a thermoplastic elastomer or a synthetic rubber and a tackifier resin, or a mixture containing a thermoplastic elastomer or a synthetic rubber and an oil. A kneader such as a kneader or an extruder for mixing a thermoplastic polymer mixture having a surface tackiness comprising a mixture containing a plasticizer in a molten state, and a molten thermoplastic polymer extruded from the kneader into a desired shape. A dividing device that divides the desired shaped body into a body, a cooling / transporting device that conveys the formed desired shaped body into pellets of substantially spherical shape using surface tension while cooling in a fluid, and the substantially spherical shaped particle. Is forced into a turbulent flow of the release agent emulsion kept at about room temperature, and the release agent emulsion And a drying device that conveys the moisture contained in the release agent on the surface of the pellets while vibrating and drying with a vibration dryer. Equipment for producing plastic polymer pellets. The release agent application device should have a Reynolds number Re ≧ 2100 when the release agent emulsion flows in a circular pipe flow, or Re ≧ 1000 when the release agent emulsion flows in an open channel. The apparatus for producing thermoplastic polymer pellets having surface tackiness according to claim 1, characterized in that: 3. The release agent coating device according to claim 1, wherein the release agent emulsion has an uneven bottom surface and / or a side surface uneven shape, or an uneven flow or an indefinite flow due to a wave-making device. An apparatus for producing a thermoplastic polymer pellet having the surface tackiness described above. 4. The surface tackiness according to claim 1, wherein the release agent coating device is a coating device in which a release agent emulsion is intentionally generated by a stirrer or the like to generate a turbulent flow. Thermoplastic polymer pellet manufacturing equipment. The vibration dryer for dehydrating the water of the applied release agent emulsion has a frequency of 120 vpm or more, an amplitude of 2 mm or more and 100 mm or less, or a vibration angle of 1 degree or more and less than 90 degrees. The apparatus for producing thermoplastic polymer pellets having surface tackiness according to claim 1, 2, 3, or 4. The vibration drier according to claim 5, wherein the drying air heated to 20 ° C. or higher has a structure in which air is blown up from holes in the vibration surface. For producing thermoplastic polymer pellets having surface tackiness.

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