JP2010208193A - Cartridge for packing high viscosity of resin composition, and plunger used therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure a required gas barrier property (moisture permeability shielding property) while restraining a cost as much as possible, in an injection-molded cartridge subjected to package of a sealing material. <P>SOLUTION: A high-density polyethylene blended with a crystalline nucleus agent is used as a resin material. A moisture permeability of the cartridge 1 gets low without searching a material of a new grade, because a density gets high by addition of the crystalline nucleus agent. A modified silicone sealing material is thereby allowed to cope with. An aluminum foil 11 is wrapped onto a barrel part 3 to cope with a case of using the sealing material of extremely high reactivity. A shoulder part 4 is allowed to cope with by a countermeasure of the extent of thickening a wall thickness, because the shoulder part 4 is near to a gate and has a high density. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cartridge for packaging a high-viscosity resin composition such as an architectural sealant (also called a sealant or caulking agent) or an adhesive, and a plunger used in the cartridge. Note that the distinction between a sealing agent and an adhesive may not be clear, and the same substance may be called a sealing agent or an adhesive by a person or manufacturer.

  In this type of cartridge, a ring-shaped shoulder plate is connected to one end of a cylindrical body, and an externally threaded extraction tube projects outwardly from the shoulder plate. Is sealed from the inside with aluminum foil (membrane). Then, after the cartridge is filled with the contents, the plunger is fitted from the other end of the cartridge, and is used by being loaded into a dedicated push gun. There are various sealants such as silicone, modified silicone, allyl, polyurethane, acrylic urethane, and polysulfide.

  Looking at the cartridge from the perspective of the material and structure, the entire cartridge is integrally molded by resin injection molding, and the body is made of paper (paper tube). It is broadly classified into one in which a lid (or head) is fixed and one in which an extruded product of resin is used for the body and a resin lid is fixed to this. In addition, the plunger is often a resin molded product, but a part made of a metal plate is also used.

  In the case of using a resin as a material for the cartridge and the plunger, generally, low density polyethylene or high density polyethylene is used (for example, Patent Document 1 as an example of using high density polyethylene). However, when the content is a material having high reactivity with moisture (water vapor) such as a modified silicone sealant, there is a problem that the content is altered and cured in a short period of time. Therefore, depending on the contents, a high gas barrier property (water vapor shielding property) is required for both the cartridge and the plunger. Conventionally, as described in Patent Documents 2 and 3, aluminum foil is adhered to the outer peripheral surface of the trunk portion and the inner surface of the shoulder plate portion as described in Patent Documents 2 and 3, while the plunger As the gas barrier property improving means, it is adopted that an aluminum foil is stuck on the inner surface and the plunger is made of a metal plate.

Japanese Patent Application Laid-Open No. 07-101478 Japanese Patent Laid-Open No. 2003-335382 JP 2008-019006 A

  Since aluminum foil (in practice, a laminated product in which a resin film is laminated on the front or back or one side is generally used) can exhibit 100% gas barrier properties, high cartridges and plungers can be covered with aluminum foil to ensure high gas barrier properties. Even if the plunger is made of a metal plate, a gas barrier property of 100% can be secured. However, affixing aluminum foil leads to increased costs due to the increased number of processing steps. In addition, when the plunger is made of a metal plate, not only the processability is reduced, but also the sealability is inferior because it can only be manufactured in a simple shape. Another problem arises.

  On the other hand, when the present inventor researched, the gas barrier property required for the cartridge and the plunger varies depending on the contents, and even if the gas barrier property is not high enough to cover the whole with aluminum foil, it may be practically used. It turned out to be. That is, it has been found that covering the whole with aluminum foil or making the plunger made of a metal plate may result in an excessive quality far exceeding the required quality.

  The present invention has been made on the basis of such knowledge. The cartridge and plunger for the high viscosity resin composition are intended to reduce the cost as much as possible while ensuring the necessary gas barrier properties.

  The present invention includes a cartridge and a plunger. The first invention (invention of claim 1) relates to a cartridge, and this cartridge is manufactured by an injection molding method using a pellet-shaped resin as a raw material and is provided for packaging of a high-viscosity resin composition. A ring-shaped shoulder plate portion is integrally connected to one end of the cylindrical barrel portion, and a pour tube is projected outwardly on the shoulder plate portion, and the barrel portion is filled with a high-viscosity resin composition. After that, the plunger is fitted from the other end. And the high density polyethylene which mixed the crystal nucleating agent is used as resin of the said raw material.

  The second invention responds to higher gas barrier properties. In the first invention, a high gas barrier layer is provided on the outer peripheral surface of at least a portion of the body portion that is filled with the high-viscosity resin composition.

  A third invention (invention 3) relates to a plunger, which is manufactured by an injection molding method using a pellet-shaped resin as a raw material, and is used by being fitted into a high viscosity resin composition packaging cartridge. It is a form which has a baseplate part and the cylinder part continuous with this. And the high density polyethylene which mixed the crystal nucleating agent is used as resin of the said raw material.

  The addition ratio of the crystal nucleating agent is preferably 1.5 to 3.5 wt% (inner coating), particularly about 2.5%. If it is lower than 1.5 wt%, a remarkable effect cannot be exhibited, and even if the addition ratio exceeds 3.5 wt%, the effect is not increased and only the cost is increased. The types of high-density polyethylene and cocoon are not uniform and the grades are different. The higher the grade (ie, the higher the density), the higher the gas barrier property. Therefore, the grade of the high density polyethylene to be used may be selected according to the type of sealing agent to be packaged. The crystal nucleating agent is also called a crystallization nucleating agent.

  As a specific means for forming the high gas barrier layer in the second and fourth inventions, a hot stamp method in which a high gas barrier film (or sheet) such as an aluminum foil (or other metal foil) or a PET resin film is attached is used. Various modes such as transferring a metal layer (or metal film) or resin layer (or resin film) by vapor deposition, depositing a metal layer, applying or coating a gas barrier resin by spraying, brushing or electrodeposition can be selected. . It can be said that the application of aluminum foil (in practice, a laminate product) is excellent in reliability.

  The crystal nucleating agent is the core of the crystal when the molten resin solidifies and crystallizes. The crystal nucleating agent accelerates the crystallization of the resin to shorten the molding cycle, and the size of the crystal is made uniform to prevent sink marks. And has the function of increasing hardness. The cartridge and the plunger have a dense structure due to the promotion of crystallization, and as a result, the gas barrier property can be improved.

  In general, silicone-based and modified silicone-based sealing agents that use cartridges and plungers are often used. Of these, silicone-based ones are made of high-density polyethylene due to their low reactivity. Although the modified silicone type has high reactivity with water vapor, it is not possible to secure the necessary gas barrier properties by simply making the cartridge or plunger made of high-density polyethylene. It was found that there was no need to cover the surface with aluminum foil.

  Then, as in the first invention and the third invention of the present application, the cartridge and the plunger are made of high-density polyethylene mixed with a crystal nucleating agent, so that a modified silicone system can be used without special processing such as attaching an aluminum foil. The sealant can be maintained for a considerable period in a state where the sealant is not altered. Accordingly, the first and third inventions of the present application are suitable for packaging modified silicone or a reactive sealant equivalent thereto. More simply, the cartridge and plunger for packaging the modified silicone or the equivalent reactive sealant can be manufactured as inexpensively as possible while maintaining the necessary gas barrier properties.

  The crystal nucleating agent is an additive for modifying the resin, but has not been used so much conventionally. One of the reasons was that it had a characteristic odor. Moreover, although the use to polyethylene is hardly carried out conventionally, it can be said that this is because polyethylene has a high crystallization speed and the merit of the crystal nucleating agent is hardly exhibited. Moreover, since the density of high density polyethylene is higher than that of low density polyethylene, it can be said that the necessity of a crystal nucleating agent was not recognized in the first place. On the other hand, the present invention has a high gas barrier property in the cartridge and the plunger itself by adding a crystal nucleating agent to high density polyethylene, and has a commercial value without a significant increase in cost. Is up.

  Some sealants have a very high reactivity such as urethane, and in this case, it may be difficult to deal with only by devising the materials of the cartridge and plunger. On the other hand, the present application can cope with this problem by providing a high gas barrier layer on the cartridge and the plunger in addition to the contrivance of the material as in the second and fourth inventions. Here, as a representative example of the high gas barrier layer, it is possible to put an aluminum foil. However, since the cartridge and the plunger originally have a high gas barrier property, the high gas barrier layer such as an aluminum foil is combined to be extremely high. Gas barrier properties can be secured.

  In addition, since the cartridge and the plunger originally have an improved gas barrier property, in the case of a cartridge, while providing a high gas barrier layer such as an aluminum foil only on the outer peripheral surface of the barrel portion, a significantly higher gas barrier property can be secured. In the case of a plunger, it is possible to ensure a much higher gas barrier property simply by providing a high gas barrier layer such as an aluminum foil only on the bottom plate. In providing a high gas barrier layer such as an aluminum foil, the same effort as before is required. The gas barrier property can be further improved, or the gas barrier property equivalent to the conventional one can be ensured in a state where the labor of processing is reduced as compared with the conventional one.

It is a figure which shows the structure of 1st Embodiment. It is a graph which shows the relationship between a density and moisture permeability (gas barrier property). (A) is a comparison table between a comparative example and an example, and (B) is a graph for comparing the moisture permeability of the comparative example and the example. It is a figure which shows 2nd Embodiment.

(1). Outline of First Embodiment Next, an embodiment of the present invention will be described. First, the form of the cartridge and the plunger will be described with reference to FIG. 1A is a plan view of the cartridge 1, FIG. 1B is a partially cutaway front view of the cartridge 1 in use, and FIG. 1C is a front sectional view of the cartridge 1 and the plunger 2 separated from each other.

  The basic form itself of the cartridge 1 and the plunger 2 is the same as the conventional one. First, the cartridge 1 is integrated with a cylindrical body 3 and a ring-shaped shoulder plate 4 connected to one end of the cylindrical body 3 and the shoulder plate 4. It consists of the extraction pipe | tube 5 connected to. A male screw for screwing a nozzle (not shown) is formed on the outer periphery of the dispensing cylinder 5. An end portion of the shoulder plate portion 4 connected to the body portion 3 is a thick portion 4a. Accordingly, the shoulder plate portion 4 is formed with an outward annular recess. The overall length of the body part 3 was about 215 mm, the outer diameter of the body part 3 was about 50 mm, and the wall thickness of the body part 3 was about 1.3 mm.

  The plunger 2 has a bottomed cylindrical shape with a bottom plate 6 and a cylindrical portion 7 integrally connected thereto, and of course, the plunger 2 is fitted into the cartridge 1 with the cylindrical portion 7 first. In the present embodiment, three ribs 8 are formed on the outer periphery of the cylindrical portion 7. The thickness of the body part 3 was about 1 mm. A sealing aluminum foil 9 is attached to the inner surface of the shoulder plate portion 4 of the cartridge 1 as an example of shielding means (membrane) for closing the dispensing cylinder 5 from the inside. The outer periphery of the sealing aluminum foil 9 is located approximately in the middle between the inner periphery and the outer periphery of the shoulder plate portion 4.

  Both the cartridge 1 and the plunger 2 are manufactured by an injection molding method using resin pellets as a raw material. As a resin material, high density polyethylene to which a crystal nucleating agent is added (blended) is used. The crystal nucleating agent is added (blended) in the process of manufacturing the resin pellets, and therefore, the injection molding machine is charged with high-density polyethylene pellets containing the crystal nucleating agent.

(2). Specific Example and Evaluation of First Embodiment Next, specific examples and evaluation of the present invention will be described with reference to the tables and graphs of FIGS. The gas barrier property (moisture permeability) and density of polyethylene products are inversely related, and the relationship is approximately shown by the graph in FIG. In other words, the relationship between the rate of increase in density and the rate of decrease in moisture permeability is a curvilinear relationship, and in the range of high-density polyethylene, the rate of decrease in moisture permeability is lower than the rate of increase in density (moisture permeability). (Water vapor permeability) is measured according to JISK7129.)

FIG. 3 shows numerical values and graphs of the comparative example and the embodiment of the present application. In each example, a sample was cut from an actual product and the density was measured. Two samples are used for each sample, and each product has a portion of the barrel 3 close to the dispensing tube 5 (on the dispensing tube) and a portion close to the opening end (on the opening). Cut out at two places. Comparative Example A, Comparative Example B, and Examples are manufactured by the applicant company, and the material of Comparative Example A is a measured value in which the melt flow index (MFR (code D)) conforms to JISK7210 (1999). 26 g / 10 min, and the manufacturer's display density was 956 kg / m ^{3 as} measured according to JIS K7112 (1999).

The resin material of Comparative Example B and the Example is common, the melt flow index is 12 g / 10 min, the manufacturer display density is 959 kg / m ³ , and the Example uses the resin material of Comparative Example B as a base material. A crystal nucleating agent is blended in an amount of 2.5 wt%. Comparative examples C and D are the products of other companies purchased in the market. Comparative example C is a molded product that is integrally molded as in the case of the present article, while comparative example D uses an extruded product on the body. ing.

  Except for Comparative Example D, each sample has a density on the side of the dispensing cylinder which is considerably lower than the density on the opening side. This is because the position of the gate in the molding die is at the tip of the dispensing cylinder 5. Due to In other words, the resin melted in the molding process is injected into the mold cavity from the gate, but the resin is not completely melted and then filled into the cavity and then pressed and solidified. As soon as it comes into contact with the inner surface of the mold, the curing starts, and as the distance from the gate increases, the pressure of the resin must be lowered. As a result, the density is higher on the side of the dispensing cylinder 5. It goes down gradually toward the open end. In Comparative Example D, there is no difference in density depending on the position, because the extruded product is formed in a uniform state over the entire length.

  Now, high density polyethylene (HDPE) is also called medium-low pressure polyethylene because of its manufacturing method, and various grades of products are provided by many manufacturers. In addition, high-density polyethylene has a higher crystallinity than low-density polyethylene, and as described above, it can be said that the use of a crystal nucleating agent was not considered due to the high crystallinity. .

  Although it can be said that the gas barrier property (moisture permeability shielding degree) of polyethylene products is generally inversely related to density, in the range of high-density polyethylene, the rate of decrease in moisture permeability is lower than the rate of increase in density. In other words, it is presumed that the industry has recognized that even if the degree of density is increased, the rate of decrease in moisture permeability is not so great.

However, for example, in the case of a modified silicone-based sealant, it has been found that the required value of moisture permeability can be cleared by slightly increasing the moisture permeability compared to the conventional case. That is, in the modified silicone, the upper limit value (threshold value) of moisture permeability required in consideration of the distribution period in the market is approximately 0.25 g / m ² · day, and the lower limit of the density for ensuring this Although the value (threshold value) is estimated to be about 952 to 953 kg / m ³ , in the present invention, the necessary moisture permeability can be reduced by adding a crystal nucleating agent to the same material as in Comparative Example B. It is secured. Further, although it seems that there is only a slight difference in moisture permeability and density between Comparative Example B and the Example, this difference is actually a threshold value (boundary value of whether or not it can be used practically). It is a value that determines whether to exceed or not.

  In order to exceed the threshold value of moisture permeability, it may be necessary to use only a raw material resin having a higher crystallinity, but in this case, the blend of raw materials (monomers, etc.) There are concerns about problems such as difficulty in crystallization and excessively rapid crystallization in the mold. On the other hand, in this invention, since a moderate grade material can be used, it is excellent in certainty and stability.

  Although the above description is for the cartridge 1, the same can be said for the plunger 2. Furthermore, since the plunger 2 is small, it can be said that the uniformity of density is higher than that of the cartridge 1. In forming the plunger 2, the gate is generally located at the center of the bottom plate 6, and therefore the density of the cylindrical portion 7 may be lower than that of the bottom plate 6. Since non-moisture permeability should just be ensured in the location, it can be said that there is no problem even if the moisture permeability is high in the cylindrical portion 7.

  Crystal nucleating agents include phosphates such as cyclic phosphate metal salts of alkylphenols, sorbitols, benzoates such as sodium benzoate, norbornene dicarboxylates, aromatics Various things, such as what combined organic phosphoric acid diester and higher fatty acid, can be used. In addition, the crystallization of the product proceeds by adding the crystal nucleating agent, but it seems that the progress of crystallization does not always lead to an increase in weight (mass) per unit volume. Although it has not yet been clarified whether this discrepancy is a measurement problem or a molding condition problem, in any case, it has been confirmed that the gas barrier property can be improved by adding a crystal nucleating agent.

(3). Second Embodiment FIG. 4 shows a second embodiment which is a specific example of claims 2 and 4. The second embodiment is based on the material exemplified in the first embodiment. First, for the cartridge 1, a first aluminum foil 11 for barrier is attached to the outer peripheral surface of the body portion 3 as an example of a high gas barrier layer. Is provided. The first aluminum foil for barrier 11 is a laminated product in which a resin film is laminated on both front and back surfaces or one surface, and adhesion using an adhesive such as a hot melt adhesive, or welding using high frequency, ultrasonic waves or a hot platen. It is pasted by various means. It is beneficial to apply treatments (corona treatment, matte finish, etc.) for improving the adhesion and weldability to the outer peripheral surface of the body portion 3.

  As shown in FIG. 1, since the plunger 2 is shipped in a state where the plunger 2 is inserted into the body portion 3 to a certain extent, the barrier first aluminum foil 11 is formed on a part of the body portion 3 on the opening side. It is pasted in the state of leaving. The first barrier aluminum foil 11 is a rectangular one and wound around the body 3 with the edges overlapped, but a tape-like one is wound around the body 3 in a spiral form. It is also possible to insert a cylindrical shape into the body 3 and attach it. It is also possible to apply aluminum foil by an insert molding method in which the aluminum foil is placed in a mold.

  A barrier second aluminum foil 12 is provided on the outer surface of the bottom plate 6 of the plunger 2. The barrier second aluminum foil 12 covers substantially the entire outer surface of the bottom plate 6. As with the cartridge 1, the bonding means for the barrier second aluminum foil 12 can use adhesion, welding, insert molding, or the like. The barrier second aluminum foil 12 can be bonded to the inner surface of the plunger 2. In this case, the entire bottom plate 6 and a part or all of the cylindrical portion can be covered with the second aluminum foil 12 for barrier. In the molded product, the moisture permeability has an inverse relationship with the thickness. Therefore, the necessary moisture permeability can be ensured only by setting the bottom plate 6 to a thickness that is, for example, about 2 to 3 times the cylindrical portion 7.

  Since the body 3 of the cartridge 1 is covered with the first aluminum foil 11 for barrier, the moisture permeability is theoretically blocked by 100%, but the shoulder plate 4 is also provided with a means for improving the gas barrier property. Is preferred. In this example, in the example shown in FIG. 4B, the thickness t of the shoulder plate 4 is made thicker than the thickness of the trunk 3 (for example, 2 to 3 times (2 to 4 mm) the thickness of the trunk 3). This is being dealt with.

  Since the cartridge 1 of the present embodiment is originally high in density and superior in gas barrier properties as compared to the conventional product, and the shoulder plate portion 4 is close to the gate and has a particularly high density, thereby ensuring a higher gas barrier property. In many cases, the necessary gas barrier properties can be secured only by increasing the thickness. Of course, depending on the required quality (moisture permeability), the thickness of the shoulder plate portion 4 may be the same as before.

  As a second means for increasing the moisture permeability of the shoulder plate portion 4, the sealing aluminum foil 9 is spread over substantially the entire inner surface of the shoulder plate portion 4 in FIG. The sealing aluminum foil 9 is affixed to the inner surface of the shoulder plate portion 4 by adhesion using a hot melt adhesive or welding using a high frequency horn. The sealing aluminum foil 9 can be attached by, for example, the following operation. That is, as indicated by a one-dot chain line, first, the outer aluminum suction tool 9 is placed on the inner surface portion of the shoulder plate portion 4 by the inner suction tool 13 that enters the trunk portion 3, and then the outer suction tool that enters the dispensing tube 5. 14, the aluminum foil 9 for sealing is changed, and then the inner adsorber 13 is retracted to the outside of the body part 3 and then a bonding tool 15 such as a hot platen or a high-frequency horn is inserted into the body part 3. Can be pasted by following the steps.

  When the sealing aluminum foil 9 is disposed on the inner surface portion of the shoulder plate portion 4 by the inner adsorber 13, the sealing aluminum foil 9 can be temporarily bonded to the shoulder plate portion 4. In this case, the holding by the outer suction tool 14 can be made unnecessary. As a means for holding the sealing aluminum foil 9 at the time of bonding with the bonding tool 15, an appropriate number of suction holes (for example, four at equal intervals in the circumferential direction) are opened in the shoulder plate portion 4, It is also possible to vacuum-seal the sealing aluminum foil 9 (since the suction hole is closed by the sealing aluminum foil 9, the gas barrier property is not affected).

  In the example shown in FIG. 4D, the sealing aluminum foil 9 covers only about half of the inner side of the shoulder plate portion 4, but the inner surface of the shoulder plate portion 4 is curved in a concave shape inward in cross section. For this reason, the outer portion of the sealing aluminum foil 9 is much thicker than before, thereby ensuring the necessary gas barrier properties. In this example, the bottom plate 6 of the plunger 2 is curved outwardly so as to be in close contact with the inner surface of the shoulder plate portion 4, and the bottom plate 6 is fitted into the dispensing cylinder 5 of the cartridge 1. A cylindrical portion 6a is provided. For this reason, it can extrude without leaving the contents.

  In the example of (D), a group of ribs 6a extending radially is provided in the plunger 2, and the second aluminum foil 12 for barrier is bonded to the end face of the group of ribs 6a. It is preferable that the sealing aluminum foil 9 covers the cylindrical portion 7. Also in this example, it is possible to eliminate the second aluminum foil 12 for barrier by increasing the thickness of the bottom plate 6.

(4). Others The present invention can be embodied in various ways other than the above embodiment. For example, it is possible to integrally form a tapered nozzle in the dispensing cylinder (in this case, of course, the external thread of the dispensing cylinder is unnecessary). It is also possible to provide a gas barrier layer such as aluminum foil bonding on the outer surface of the shoulder plate portion of the cartridge.

DESCRIPTION OF SYMBOLS 1 Cartridge 2 Plunger 3 Body part 4 Shoulder plate part 5 Pipe | pipe 6 Plunger bottom plate 7 Plunger cylinder part 9 Sealing aluminum foil 11 Barrier first aluminum foil 12 Barrier second aluminum foil

Claims (4)

It is manufactured by injection molding using a pellet-shaped resin as a raw material, and is provided for packaging of a high-viscosity resin composition. A ring-shaped shoulder plate is integrally connected to one end of a cylindrical body, and the shoulder plate The high-viscosity resin composition is such that the pouring tube protrudes outward, and the plunger is fitted from the other end after filling the barrel with the high-viscosity resin composition. Cartridge for
The material resin is high density polyethylene mixed with a crystal nucleating agent,
High viscosity resin composition packaging cartridge. A high gas barrier layer is provided on the outer peripheral surface of the portion filled with at least the high-viscosity resin composition in the body portion.
The high viscosity resin composition packaging cartridge according to claim 1. It is manufactured by injection molding using a pellet-shaped resin as a raw material and is used by being fitted into a cartridge for packaging a high viscosity resin composition, and has a form having a bottom plate portion and a cylindrical portion continuous therewith,
The material resin is high-density polyethylene mixed with a crystal nucleating agent.
A plunger used for a cartridge for packaging a high viscosity resin composition. A high gas barrier layer is provided on at least the outer or inner surface of the bottom plate,
The plunger used for the high viscosity resin composition packaging cartridge according to claim 3.

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