Dispenser For Highly Viscous Fluid

Abstract

The present invention relates to a dispenser for discharging a highly viscous fluid which possesses a viscosity ranging from 10 to 1,000 Pa·s at 25° C. and contains filler particles, the dispenser comprising: (i) a highly viscous fluid-supply part (A) equipped with a container (3) containing said highly viscous fluid (M) and possessing an outlet (3a) of said highly viscous fluid, a plunger (2) capable of discharging said highly viscous fluid from said outlet by pressing said highly viscous fluid contained in said container, and a servomotor (4) driving said plunger; and (ii) a highly viscous fluid-discharge part (B) equipped with a pipe (7) arranged for delivering said highly viscous fluid discharged from said outlet, an openable and closable valve (8) connected to said pipe, and a discharge port (9) for discharging said highly viscous fluid. The dispenser according to the present invention can stably discharge a specified amount of a highly viscous fluid containing filler particles for a long period of time, and can be used even in a clean room.

Description

TECHNICAL FIELD

The present invention relates to a dispenser which can supply a specified amount of a highly viscous fluid and use thereof.

Priority is claimed on Japanese Patent Application No. 2010-46768, filed on Mar. 3, 2010, the content of which is incorporated herein by reference.

BACKGROUND ART

Electronic devices such as semiconductor devices and the like produce heat during use. For this reason, in order to prevent damage or performance degradation caused by increased temperatures to the electronic devices, it is necessary to remove heat from the electronic devices.

As a means for removing heat from electronic devices, for example, conducting heat from heating elements such as semiconductor elements and the like in the electronic devices to a radiator such as a heat pipe, a heatsink or the like has been widely carried out. In addition, in order to effectively conduct the heat from the heating element to the radiator, for example, a grease having thermal conductivity is applied between the heating element and the radiator.

As described in Japanese Unexamined Patent Application, First Publication No. 2008-19426, Japanese Unexamined Patent Application, First Publication No. 2008-274036, and Japanese Unexamined Patent Application, First Publication No. 2007-99821, a silicone grease having thermal conductivity contains a relatively large amount of filler particles comprising a material having thermal conductivity such as zinc oxide, aluminum oxide or the like, in a silicone oil base, and possesses an increased viscosity. In addition, it is necessary to accurately apply a small amount of the aforementioned grease between a radiator and a fine heating element such as a semiconductor element or the like. Therefore, the aforementioned grease is usually applied by means of a dispenser equipped with a pump controllable by means of, for example, a computer or the like.

DISCLOSURE OF INVENTION

Technical Problems

The filler particles are relatively hard. For this reason, when a silicone grease containing the filler particles is applied by means of a dispenser, the inner part of the dispenser is easily abraded with the filler particles. Therefore, the aforementioned grease may leak in a short time from, for example, a pump part of the dispenser due to abrasion. Thereby, there are inconveniences that include not only difficulties in supplying a specified amount of a grease by means of a dispenser, but also contamination of the surrounding environment of the dispenser with the aforementioned leaked grease. In addition, an instrument in which the aforementioned contamination may occur cannot be used in, for example, a clean room at which the preparation of electronic devices is carried out.

In addition, in the case of using a dispenser having an oil hydraulic drive mechanism in order to apply a highly viscous silicone grease, there is usually a risk of oil leaking, and the environment may be contaminated. Therefore, a device of an oil hydraulic drive type in which a risk of oil leaking even with an extremely small amount is present cannot be used in, for example, a clean room.

The present invention has an objective to provide a dispenser which can stably discharge a specified amount of a highly viscous fluid containing filler particles for a long period of time, and can be used even in a clean room.

Technical Solution

The objective of the present invention can be achieved by a dispenser for discharging a highly viscous fluid which possesses a viscosity ranging from 10 to 1,000 Pa·s at 25° C. and contains filler particles, the dispenser comprising:

• • (i) a highly viscous fluid-supply part equipped with a container containing said highly viscous fluid and possessing an outlet of said highly viscous fluid, a plunger capable of discharging said highly viscous fluid from said outlet by pressing said highly viscous fluid contained in said container, and a servomotor driving said plunger; and
  • (ii) a highly viscous fluid-discharge part equipped with a pipe arranged for delivering said highly viscous fluid discharged from said outlet, an openable and closable valve connected to said pipe, and a discharge port for discharging said highly viscous fluid.

The dispenser of the present invention is preferably equipped with a conversion mechanism for converting a rotary drive of said servomotor into a linear drive.

The dispenser of the present invention is preferably equipped with a packing between said plunger and said container.

The dispenser of the present invention is preferably capable of controlling the opening and closing of said valve and/or driving of said servomotor by detecting a pressure exerting on said highly viscous fluid. In particular, a discharged amount of said highly viscous fluid can preferably be controlled by means of controlling the opening and closing of said valve and/or driving of said servomotor.

The single amount discharged of said highly viscous fluid preferably ranges from 1 to 10 g.

In the dispenser of the present invention, the part of said container and/or said plunger contacting at least said highly viscous fluid is preferably abrasion-resistant.

Said filler particles comprise at least one selected from the group consisting of metals, inorganic oxides, inorganic nitrides, and inorganic carbides. In addition, an amount of said filler particles preferably ranges from 50 to 99% by mass with respect to the total mass of the highly viscous fluid.

Said highly viscous fluid is preferably a silicone grease.

Advantageous Effects

The dispenser of the present invention can stably discharge a specified amount of a highly viscous fluid containing filler particles for a long period of time, and can be used even in a clean room. Therefore, the dispenser of the present invention can be suitably used in the preparation of electronic devices in a clean room. In particular, the dispenser of the present invention can accurately discharge a highly viscous fluid even in a small amount by means of accurate electrical drive control with a servomotor. For this reason, a small amount of the highly viscous fluid can be accurately applied between a heating element and a radiator, and thereby, a radiator structure for use in an electronic device can be easily produced.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view showing an embodiment of a dispenser of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

One mode of the present invention is a dispenser for a highly viscous fluid containing filler particles.

The filler particles are preferably formed from a material possessing thermal conductivity. The material may be a single type one or be combined with two or more types thereof. As examples of materials forming said filler particles, mention may be made of, for example, metals such as aluminum, gold, silver, copper, nickel, iron and the like; inorganic oxides such as aluminum oxide, zinc oxide, nickel oxide, titanium oxide, silicon oxide, vanadium oxide, copper oxide, iron oxide, silver oxide and the like; inorganic nitrides such as aluminum nitride, boron nitride, silicon nitride and the like; inorganic carbides such as silicon carbide, carbon, diamond and the like; and mixtures thereof. The material forming the filler particles is preferably an inorganic oxide, and more preferably a metal oxide such as aluminum oxide, zinc oxide or the like.

The blending amount of the filler particles is not particularly restricted. In general, if the amount is remarkably reduced, thermal conductivity may be reduced. On the other hand, if the blending amount is remarkably increased, thermal conductivity can be improved, but a viscosity of the highly viscous fluid may be increased, and poor operationability may be exhibited. Therefore, although the blending amount of the filler particles may vary depending on the types of the materials, the amount may range from 50 to 99% by mass, preferably ranges from 60 to 98% by mass, more preferably ranges from 70 to 97% by mass, and furthermore preferably ranges from 80 to 96% by mass, with respect to the total mass of the highly viscous fluid.

Said highly viscous fluid has a viscosity at 25° C. ranging from 10 to 1,000 Pa·s and preferably ranging from 100 to 500 Pa·s. If the viscosity is below 10 Pa·s, dripping of the fluid may easily occur. On the other hand, if the viscosity exceeds 1,000 Pa·s, discharging properties may be reduced, and for this reason, handling properties of the fluid may become poor. The viscosity is measured by means of a rheometer.

Said highly viscous fluid preferably exhibits a grease property, and in particular, is preferably a grease possessing thermal conductivity. In addition, said grease preferably possesses a coefficient of thermal conductivity measured at 25° C. by means of a hot wire method which is preferably 0.5 W/m·K or more, more preferably 1.0 W/m·K or more, and in particular, preferably 2.0 W/m·K or more.

In the case where said highly viscous fluid is a grease, as examples of a base oil forming the grease together with said filler particles and the like, mention may be made of mineral oil-based ones such as paraffin oils and naphthene oils; synthetic ones such as α-olefin polymers or oligomers, polyalkylene glycol, diesters (dibasic acid esters), trimellitic acid esters, polyol esters, perfluoro polyethers, polyphenyl ethers, silicones, and the like. In view of electrical insulation properties and thermal resistance, the base oil is preferably a silicone. Therefore, said highly viscous fluid is preferably a silicone grease in which a silicone is used as a base oil.

The aforementioned silicone greases are, in general, commercially available. As examples thereof, mention may be made of, for example, SC4471CV, SC4490CV, TC-5021, TC-5022, and TC-5351, manufactured by Dow Corning Toray Co., Ltd.

The dispenser of the present invention can be used in order to discharge the aforementioned highly viscous fluid. Namely, the dispenser of the present invention is a dispenser for discharging a highly viscous fluid which has a viscosity at 25° C. ranging from 10 to 1,000 Pa·s and preferably ranging from 100 to 500 Pa·s, and contains filler particles.

The dispenser of the present invention contains

• • (1) a highly viscous fluid-supply part equipped with a container containing said highly viscous fluid and possessing an outlet of said highly viscous fluid, a plunger capable of discharging said highly viscous fluid from said outlet by pressing said highly viscous fluid contained in said container, and a servomotor driving said plunger; and
  • (2) a highly viscous fluid-discharge part equipped with a pipe arranged for delivering said highly viscous fluid discharged from said outlet, an openable and closable valve connected to said pipe, and a discharge port for discharging said highly viscous fluid.

One of the characteristics of the dispenser of the present invention is that when the dispenser discharges the highly viscous fluid containing filler particles, the dispenser employs no mechanism of pumping a fluid by means of an operation of a rotator such as a conventional pump.

In the conventional pump using a rotator, the rotator itself and a sealing part of said rotator are rapidly abraded away by contacting with the filler particles, and therefore, it is difficult to accurately supply said viscous fluid. In addition, when abrasion further proceeds, said highly viscous fluid is leaked from the pump, and the environment may be contaminated.

In contrast, the dispenser of the present invention delivers the highly viscous fluid containing filler particles under pressure by means of not a rapidly-rotating rotator, but a plunger which carries out a linear movement. Thereby, in the dispenser of the present invention, a part contacting said highly viscous fluid containing filler particles is restricted to the tip periphery of the plunger. In addition, the plunger does not rapidly rotate, and for this reason, a relative speed of the highly viscous fluid and the plunger at the time of contacting them can be controlled. Therefore, it is difficult to abrade the dispenser of the present invention even if the dispenser contacts the highly viscous fluid containing filler particles, and there is no difficulty of volumetric or gravitmeric feeding of said highly viscous fluid due to abrasion caused by filler particles.

In addition, another characteristic of the dispenser of the present invention is that the dispenser is not operated by means of an oil hydraulic drive mechanism.

In general, not only in the oil-hydraulic drive-control, but also in the liquid-hydraulic drive-control, power is led via a liquid, and for this reason, a slight time lag for leading power occurs. In addition, properties such as viscosity of the liquid may vary depending on temperatures, and performance may be affected. Therefore, in a usage in which high accuracy is required, for example, at the time of the preparation of an electronic device, it is difficult to control a discharged amount with a required degree of accuracy in an oil-hydraulic dispenser. In particular, as the discharged amount is reduced, it is extremely difficult to maintain a specified amount which is discharged.

Therefore, in the dispenser of the present invention, a plunger is drive-controlled by means of an electric drive mechanism using a servomotor. The servomotor is completely electrically drive-controlled, and for this reason, the plunger can be extremely accurately driven. Therefore, even in the usage of the preparation of an electronic device, a discharged amount can be controlled with a high degree of accuracy even if the discharged amount is small. In addition, a liquid such as oil is not used, and for this reason, the dispenser of the present invention can be used even in a clean room. In addition, the electric drive-control is superior to the oil-hydraulic drive-control, in view of energy effectiveness.

Therefore, the dispenser of the present invention can discharge a specified amount of a highly viscous fluid containing filler particles for a long period of time by virtue of delivering under pressure with a plunger which is abrasion-resistant and using an electric drive-control with a servomotor, and the dispenser can also be used even in a clean room.

For delivering a highly viscous fluid such as grease containing filler particles under pressure, a large output power is in general required, and for this reason, an oil-hydraulic drive-control which can easily obtain a large output power is usually used. In contrast, the dispenser of the present invention tends to discharge a highly viscous fluid in a relatively small amount such as about 1 to 10 g, and for this reason, a discharge power can be sufficiently obtained by means of drive due to a servomotor.

In the servomotors, there are a rotation drive-type servomotor and a linear drive-type servomotor (linear servomotor). In the case of using the linear servomotor, the linear servomotor can be directly connected with the plunger. In the case of using the rotation drive-type servomotor, a converting mechanism such as a screw jack, ball screw or the like for converting the rotation drive of the servomotor into the linear drive is preferably equipped.

Next, modes for using the dispenser of the present invention are described with reference to the drawings. FIG. 1 is a schematic view showing one embodiment of a dispenser of the present invention.

A dispenser shown in FIG. 1 is equipped with a pressure-resistant container 3 for containing highly viscous fluid M such as a grease containing filler particles in a casing 1. Said pressure-resistant container 3 possesses an outlet 3a at the vicinity of a bottom face thereof. In the embodiment shown in FIG. 1, one outlet 3a is provided, but plural outlets may be present.

In the embodiment shown in FIG. 1, said pressure-resistant container 3 is in the form of a cylinder of which the upper end face is open. A plunger 2 provided with an end part 2a in the form of a cylinder coinciding with the inner peripheral form of said pressure-resistant container 3 is engaged in said pressure-resistant container 3 so that said highly viscous fluid M contained in said pressure-resistant container can be pressed from said upper end face. A shaft 2b of said plunger 2 is held by a screw jack 6 so that said plunger 2 can be freely moved vertically. Said shaft 2b passes through the inner face of said maintained casing 1 via the opening of said casing 1, which is not shown in the drawing.

Said screw jack 6 is connected to a rotation drive axis of said servomotor 4 of rotation drive type via a coupling 5, and the rotation drive of said servomotor 4 can be transmitted to said screw jack 6 from said axis via coupling 5. Said servomotor 4 can be controlled by means of controlling system which is not shown in the drawing. Said screw jack 6 functions as a conversion mechanism of converting the rotation drive of the servomotor into a linear drive and transmitting to said plunger 2. As said conversion mechanism is not restricted to a screw jack, a ball screw or the like may be used, for example.

In the embodiment shown in FIG. 1, said pressure-resistant container 3, plunger 2, and servomotor 4 constitute a highly viscous fluid supply part A.

In order to enhance liquid-tight properties, a packing is preferably provided at a part contacting said plunger 2 and pressure-resistant container 3. The material for the packing is not particularly restricted. In order to prevent abrasion caused by contacting filler particles in said highly viscous fluid M, at least the surface of the packing is preferably formed from an abrasion-resistant material.

Since said pressure-resistant container 3 and the end part 2a of said plunger 2 are parts contacting said highly viscous fluid M containing filler particles, at least the inner peripheral surface of said pressure-resistant container 3 and the surface of said end part 2a are preferably formed from abrasion-resistant materials. The abrasion-resistant materials are not particularly restricted, and conventionally known abrasion-resistant materials such as high-chromium steel, various hard ceramics and the like can be used therefor.

In addition, the dispenser shown in FIG. 1 possesses a pipe 7 connected to said outlet 3a of said pressure-resistant container 3, for delivering said highly viscous fluid M discharged from said outlet 3a. Manometers 10, 11 for measuring the pressure in said pipe 7 are respectively provided at the beginning end periphery and the terminal end periphery. Said manometers 10, 11 are connected to a control system which is not shown in the drawing. On the basis of the results measured by said manometers 10, 11, said servomotor 4 can be drive-controlled. Said pipe 7 is connected to a valve 8 equipped with a nozzle 9 for discharging said highly viscous fluid M, and said highly viscous fluid M delivered by said pipe 7 can be discharged via said valve 8 and nozzle 9. It is not necessary to integrate said valve 8 and nozzle 9, and they can be arranged at any part of said pipe 7. In order to accurately control a discharged amount, said valve 8 is preferably provided at the place closest to said nozzle 9 as possible.

In the embodiment shown in FIG. 1, said pipe 7, valve 8 and nozzle 9 constitute a highly viscous fluid-discharge part B.

In the case of discharging said highly viscous fluid M using said dispenser shown in FIG. 1, first, said highly viscous fluid M is fed in said pressure-resistant container 3. In the embodiment shown in FIG. 1, said plunger 2 is pulled up to open the upper end face of said pressure-resistant container 3, and said highly viscous fluid M containing filler particles is fed in said pressure-resistant container 3 from a feeding means which is not shown in the drawing. A feeding port may be provided in said pressure-resistant container 3, and said highly viscous fluid M may be fed in said pressure-resistant container 3 from said feeding port. In this case, it is not necessary to open said upper end face, and for this reason, the possibility of mixing contaminants from the outer world in said highly viscous fluid M can be prevented.

Next, said servomotor 4 is driven by a signal from said controlling means which is not shown in the drawing, said plunger 2 is pushed in said pressure-resistant container 3, and the highly viscous fluid in said pressure-resistant container 3 is pressed and extruded. Thereby, said highly viscous fluid M is discharged from said outlet 3a of said pressure-resistant container 3 to said pipe 7. In addition, said highly viscous fluid M discharged from said outlet 3a is delivered under pressure in said pipe 7, and discharged from said nozzle 9 via said valve 8.

The pressure of said highly viscous fluid M in said pipe 7 is detected by means of manometers 10, 11, and transferred to said controlling system. In the embodiment shown in FIG. 1, on the basis of the information transferred to said controlling system, said servomotor 4 and/or valve 8 are drive-controlled. For example, while said valve 8 is opened, in order to compensate pressure reduction of said highly viscous fluid M, pressing power of said plunger 2 is increased by increasing the number of revolutions of said servomotor 4. On the other hand, while said valve 9 is closed, pressing power of said plunger 2 is reduced by reducing the number of revolutions of said servomotor 4. Thereby, while said valve 8 is opened, the pressure of said highly viscous fluid M is maintained to a targeted level, and the discharged amount can be controlled to a specified amount. Thereby, the amount of said highly viscous fluid M discharged from said nozzle 9 can be accurately controlled. The single discharged amount of said highly viscous fluid M from said nozzle 9 is not particularly restricted, and preferably ranges from 1 to 10 g and may range from 1 to 5 g.

A thermometer may be set in said pressure-resistant container 3 and/or pipe 7 to detect the temperature of said highly viscous fluid M, and on the basis of the results obtained by the measurements, the revolutions of said servomotor 4 and/or opening and closing of said valve 8 may be controlled.

As described above, the dispenser of the present invention can be used in a clean room, and for this reason, the dispenser can be preferably used in the preparation of an electronic device equipped with various radiation constructions carried out in a clean room.

In particular, the dispenser of the present invention can accurately discharge a highly viscous fluid for a long time even in a small amount by means of accurate electronic drive-control using a servomotor. For this reason, a radiation construction required for use in an electronic device can be produced with high accuracy.

EXAMPLES

Hereinafter, the present invention is described in detail with reference to examples and comparative examples. It should be understood that the present invention is not restricted to the examples.

Example 1

A silicone grease (TC-5351, manufactured by Dow Corning Toray Co., Ltd.) having a thermal conductivity of 2.9 W/m·K was intermittently discharged by means of the dispenser shown in FIG. 1. The viscosity thereof was measured by means of a rheometer (AR 550, manufactured by TA Instruments) under the condition of geometry: parallel plate with a diameter of 20 mm, gap: 200 μm, and shear rate: 10.0 (1/s). As a result, the viscosity of said silicone grease at 25° C. was 318 Pa·s.

More particularly, said servomotor 4 was driven and while the silicone grease in said pressure-resistant container 3 is pressed by means of said plunger 2, said valve 8 was opened for 15 seconds. During this, the weight of the grease discharged from said nozzle 9 was measured, and discharge stability was evaluated. The dischargements of said silicone grease were carried out 4,000 times. The results are shown in Table 1.

	TABLE 1
	Initial	9.5 hours	22 hours
	stage	elapsed	elapsed
	Minimum amount	3.583	3.593	3.458
	discharged (g)
	Maximum amount	3.614	3.611	3.51
	discharged (g)
	(Maximum amount	0.031	0.018	0.052
	discharged) −
	(Minimum amount
	discharged) (g)
	Average (g)	3.604	3.602	3.485
	Standard deviation	0.008	0.0048	0.0095

Subsequently, discharging was carried out until 500 hours elapsed. As a result, no problems such as leakage of the grease at the supply part of the highly viscous fluid of the dispenser were found.

Comparative Example 1

The change of a discharged amount of the silicone grease over time was evaluated in the same manner as described in Example 1, using a dispenser which was the same as that used in Example 1, with the exception of replacing the supply part of the highly viscous fluid in FIG. 1 with a pail pump (manufactured by Taiyo Techno Ltd.). After 300 hours elapsed from the stat of the evaluation, leakage of the silicone grease from the shaft of the pail pump was remarkably observed. After 475 hours, a large amount of leakage was observed. As a result of analyses of the shaft and the packing in the vicinity of the shaft, considerable abrasion occurred at both the shaft and the packing.

Comparative Example 2

The change of a discharged amount of the silicone grease over time was evaluated in the same manner as described in Example 1, using a dispenser which was the same as that used in Example 1, with the exception of replacing said servomotor 4 as the drive means of said plunger 2 in FIG. 1 with an oil hydraulic cylinder. The results are shown in Table 2.

TABLE 2
Initial
stage
Minimum amount     4.00
discharged (g)
Maximum amount     4.11
discharged (g)
(Maximum amount    0.11
discharged) −
(Minimum amount
discharged) (g)
Average (g)        4.07
Standard deviation 0.0346

It can be seen that in Comparative Example 2, the discharged amounts largely varied even in the initial stage of the discharging, as compared with Example 1. Therefore, it is difficult to accurately provide a specified amount of a highly viscous silicone grease with a hydraulic drive system.

INDUSTRIAL APPLICABILITY

The dispenser of the present invention can be suitably used, for example, in the preparation of an electronic device in a clean room. In particular, the dispenser of the present invention can be suitably used in the preparation of an electronic device containing a radiation structure in which a grease having thermal conductivity is present between a heating element such as a semiconductor element or the like and a radiator such as a heat pipe, a heatsink, or the like.

DESCRIPTION OF SYMBOLS

1: Casing, 2: Plunger, 3: Pressure-resistant container, 4: Servomotor, 5: Coupling, 6: Screw jack, 7: Pipe, 8: Valve, 9: Nozzle, 10,11: Manometers.

Claims

1. A dispenser for discharging a highly viscous fluid which possesses a viscosity ranging from 10 to 1,000 Pa·s at 25° C. and contains filler particles, the dispenser comprising:

(i) a highly viscous fluid-supply part equipped with a container containing said highly viscous fluid and possessing an outlet of said highly viscous fluid,

a plunger capable of discharging said highly viscous fluid from said outlet by pressing said highly viscous fluid contained in said container, and

a servomotor driving said plunger; and

(ii) a highly viscous fluid-discharge part equipped with a pipe arranged for delivering said highly viscous fluid discharged from said outlet,

an openable and closable valve connected to said pipe, and

a discharge port for discharging said highly viscous fluid.

2. The dispenser according to claim 1, further comprising a converting mechanism for converting a rotation drive of said servomotor into a linear drive.

3. The dispenser according to claim 1, further comprising a packing provided between said plunger and said container.

4. The dispenser according to claim 1, which can control the opening and closing of said valve and/or driving of said servomotor by detecting a pressure exerting on said highly viscous fluid.

5. The dispenser according to claim 1, which can control a discharged amount of said highly viscous fluid by controlling the opening and closing of said valve and/or driving of said servomotor by detecting a pressure exerting on said highly viscous fluid.

6. The dispenser according to claim 1, wherein a single amount discharged of said highly viscous fluid ranges from 1 to 10 g.

7. The dispenser according to claim 1, wherein a part of said container and/or said plunger contacting at least said highly viscous fluid is abrasion-resistant.

8. The dispenser according to claim 1, wherein said filler particles comprise at least one selected from the group consisting of metals, inorganic oxides, inorganic nitrides, and inorganic carbides.

9. The dispenser according to claim 1, wherein an amount of said filler particles ranges from 50 to 99% by mass with respect to the total mass of said highly viscous fluid.

10. The dispenser according to claim 1, wherein said highly viscous fluid is a silicone grease.

11. The dispenser according to claim 8, wherein an amount of said filler particles ranges from 50 to 99% by mass with respect to the total mass of said highly viscous fluid.

12. The dispenser according to claim 11, wherein said highly viscous fluid is a silicone grease.