KR20130020578A - Sheet for regenerating mold - Google Patents

Abstract

PURPOSE: A sheet for mold regeneration capable of easily distinguishing the mixed state of composites is provided to exhaust air existing within a cavity although the opening part of the cavity is small, thereby improving the filling ability of a mold cleaning material and the cleaning ability in the cavity. CONSTITUTION: A sheet for mold regeneration is composed of a paper sheet or a textile sheet and a mold cleaning material. The mold cleaning material including an unvulcanized rubber composite or a thermohardening resin composite is formed on at least one surface of the paper sheet or the textile sheet to be protruded with a fixed pattern having an air vent hole. At the part of the air vent hole on the surface of the paper sheet or textile sheet, a thin film(3) including the composites is formed; therefore the mixed state of the composites forming the pattern is distinguished from the forming state of the thin film. The thin film has a thickness less than 500μm. The pattern has a non-planar top. The non-planer top is formed as a protruded part having the radius of curvature of 0.2 to 3.0mm range.

Description

Sheet for mold regeneration {SHEET FOR REGENERATING MOLD}

TECHNICAL FIELD This invention relates to the sheet | seat for metal reproduction used for cleaning the mold surface of a metal mold | die.

In the step of encapsulating a semiconductor element into a resin through transfer molding, generally, resin molding using a mold is repeatedly performed. As the number of times of repeating the molding of the resin increases, dirts such as components, burrs, dusts, etc. extruded from the resin accumulate on the mold surface, particularly the cavity surface. Such dirt lowers the releasability when the molded article is taken out of the mold and forms a rough surface on the molded article. Therefore, the mold surface (cavity surface) of the mold is cleaned every predetermined number of molding repetitions (number of shots).

In order to perform cleaning in the above-mentioned manner, a method of using a mold cleaning material formed in the form of a sheet has been proposed (see Patent Document 1, for example). The method includes combining the upper mold and the lower mold with the mold cleaning material sandwiched between the upper mold and the lower mold such that the mold cleaning material is filled in the cavity; Performing heat forming in the above-described state to allow dirt to adhere to the mold cleaning material; And demolding the mold cleaning material to remove dirt from the mold surface (cavity surface) of the mold together with the mold cleaning material.

Moreover, the applicant of this invention proposes the sheet | seat for metal mold | die reproduction which improved the cleaning property (for example, refer patent document 2 and 3). The mold regeneration sheet is formed of a paper sheet or a fabric sheet provided on at least one surface so that the mold cleaning material protrudes in a predetermined pattern having air gaps. By using this mold regeneration sheet, the air in the cavity can be easily discharged from the air bleeding gap. Thus, no air remains in the cavity, and the mold cleaning material can be filled to every corner of the cavity. As a result, cleaning can be performed to every corner of the cavity, and the cleaning property is improved.

Japanese Patent Laid-Open No. 2004-130819 Japanese Patent Publication No. 2007-196586 Japanese Patent Publication No. 2008-132759

However, there are some cases in which dirt is not sufficiently removed even if the sheet for regenerating the mold having improved cleaning properties is used. Therefore, the inventor of the present invention investigated the cause of such a problem, and confirmed that if the composition of the mold cleaning material is mixed unevenly, it leads to a decrease in the filling of the cavity of the mold cleaning material.

This invention is made | formed in view of the above-mentioned situation, and makes it a subject to provide the sheet | seat for metal regeneration which is high in cleaning property and can identify the mixed state of the composition of metal mold | die cleaning material.

In order to achieve the above object, the present invention relates to the following items (1) to (11).

(1) a sheet for mold regeneration,

Paper sheets or fabric sheets; And

A mold cleaning material comprising an unvulcanized rubber-based composition or a thermosetting resin-based composition, and formed to protrude in a predetermined pattern having air gaps on at least one side of the paper sheet or fabric sheet.

And a thin film comprising the composition is formed on the surface portion of the paper sheet or the fabric sheet positioned in the air venting air gap portion, and a mixed state of the composition forming the pattern is a formation state of the thin film. A sheet for regenerating a mold, which can be identified from.

(2) The sheet for mold regeneration according to (1), wherein the thin film has a thickness of 500 μm or less.

(3) The sheet for metal mold recycling according to (1) or (2), wherein the pattern has a non-flat top.

(4) The sheet for regenerating die according to (3), wherein the non-flat top is formed of a convex portion having a radius of curvature in the range of 0.2 mm to 3.0 mm.

(5) The sheet for metal mold recycling according to any one of (1) to (4), wherein the pattern is formed of a plurality of bands or a plurality of dots.

(6) In (5), wherein the strip or dot has a width and a thickness in the range of 1 mm to 5 mm, respectively, and the interval between neighboring strips or points is set in the range of 1 mm to 5 mm. Sheet for mold regeneration.

(7) The sheet for metal regeneration according to (5), wherein the interval between the adjacent bands or dots is set to 0.5 to 2.0 times the width of the bands or dots.

(8) The sheet for metal regeneration according to (5), wherein the width of the strip or dot is set to 0.8 to 1.2 times the thickness of the strip or dot.

(9) The sheet for regenerating die according to any one of (1) to (8), wherein the fabric sheet is a nonwoven fabric.

(10) The sheet for regenerating die according to (9), wherein the nonwoven fabric is a spunbond nonwoven fabric.

(11) The sheet for reclaiming metal mold according to any one of (1) to (10), wherein the fabric sheet is embossed.

The inventor of the present invention, as suggested by the applicant of the present invention, utilizes the high cleaning property of the sheet for regenerating the mold, which is provided so that the mold cleaning material protrudes in a predetermined pattern having air gaps on at least one side thereof. In order to make it possible to distinguish the mixed state of the material for metal mold regeneration, studies have been conducted. As a result, when this inventor forms the thin film containing the said mold cleaning material in the surface part of the said paper sheet or the textile sheet located in the said air bleed space part, from the formation state of this thin film, the said mold cleaning material We found that we could identify the mixed state of. The present invention is based on these findings.

More specifically, the mold cleaning material includes an unvulcanized rubber-based composition or a thermosetting resin-based composition, but inorganic fillers such as silica powder or titanium dioxide are also dispersed in an undissolved state. As described above, if the inorganic filler is unevenly dispersed, the mold cleaning material is insufficiently filled in the cavity, resulting in deterioration of the cleaning property. Non-uniform dispersion of the inorganic filler results in thick mold cleaning material in the protruding pattern, making identification impossible. However, when the thin film is formed from the composition, when the inorganic filler is uniformly dispersed, the thin film becomes uniform in color, and the surface thereof becomes smooth. When the inorganic filler is unevenly dispersed, the color tone of the thin film appears unevenly. In addition, when the inorganic filler is not dispersed and forms a mass, the mass appears as a convex portion on the surface of the thin film. This difference in thin film formation state can be visually identified.

When the thin film is identified by the color tone as described above, the inorganic filler may have a color that stands out compared to the color of the main component (base material) of the composition of the thin film (mold cleaning material). For example, when the main component of the composition is colorless transparent, a colored (eg white) inorganic filler can be used. If the main component of the composition is light (eg white), then a dark (eg black) inorganic filler can be used. If the main component of the composition is a dark color (eg brown or gray), a light color (eg white) inorganic filler can be used. In other words, the color of the main component of the composition and the color of the inorganic filler may be colors opposite to each other or in contrast, in terms of ease of identification.

The sheet for regenerating the mold according to the present invention is a paper sheet or a fabric sheet in which a mold cleaning material including an unvulcanized rubber-based composition or a thermosetting resin-based composition protrudes on at least one surface in a predetermined pattern having air bleeding voids. Is formed. Therefore, when the mold is cleaned using the sheet for regenerating the mold according to the present invention, the mold cleaning material can be filled into the cavity while discharging the air present in the cavity through the air bleeding gap. As a result, air does not remain in the cavity, the filling property of the mold cleaning material into the cavity is improved, and cleaning can be performed to every corner of the cavity. Moreover, the sheet | seat for metal mold | die regeneration which concerns on this invention is provided with the thin film containing the said composition in the surface part of the said paper sheet or the textile sheet located in the said air bleeding gap part. Since the color tone or surface state of this thin film shows the mixed state of the said composition, it becomes possible to identify the mixed state of the said composition which forms the said pattern in the formation state of the said thin film. As a result, when the composition is in a heterogeneous mixed state, the composition may be regarded as unsuitable for cleaning the mold and may not be actually used. In other words, the thin film can be used for quality control of the sheet for reproducing a mold according to the present invention.

In particular, when the thickness of the thin film is 500 μm or less, the mixed state of the composition may be easily expressed on the thin film. Thus, the mixed state of the composition can be more easily identified.

In addition, when the top part of the pattern is formed to be non-flat, even if the opening of the cavity is small, air existing in the cavity can be easily discharged. This is because the top of the mold cleaning material partially blocks the opening. As a result, the filling property of the mold cleaning material is further improved, and the cleaning property in the cavity is further improved.

In particular, when the non-planar top of the pattern consists of convex portions having a radius of curvature in the range of 0.2 mm to 3.0 mm, the filling property of the mold cleaning material and the cleaning property in the cavity are further improved.

In the case where the pattern is formed of a plurality of bands or a plurality of points, it is easy to set the shape and dimensions of the pattern and the air bleeding void. In addition, it is easy to set the mold cleaning material into a pattern suitable for filling the cavity.

In particular, when the bands or dots are set to have a width and thickness in the range of 1 mm to 5 mm, respectively, and the intervals between neighboring bands or points are set in the range of 1 mm to 5 mm, the semiconductor element is made of resin. Dimensions suitable for cleaning of the transfer molding die used to enclose the furnace can be obtained. Therefore, the metal mold | die for transfer molding can be cleaned appropriately.

In addition, when the distance between adjacent bands or dots is set to 0.5 to 2.0 times the width of the bands or dots, the balance between the volume of the air bleed voids and the amount of the mold cleaning material is appropriate. In this way, the air discharge from the cavity and the filling of the mold cleaning material can be more properly performed.

On the other hand, the pattern whose width | variety of the said strip | belt or the dot is set in the range of 0.8 times-1.2 times the thickness has excellent shape stability, and the filling property of a metal mold | die cleaning material improves remarkably.

When the fabric sheet is formed of a nonwoven fabric, the fabric sheet has a rough surface, thereby improving the anchoring effect of the mold cleaning material, thereby improving the adhesion between the fabric sheet and the mold cleaning material.

More specifically, in the case where the nonwoven fabric is a spunbond nonwoven fabric, there is no directivity in the tensile strength relatively, and the stress applied during the heat molding is easily absorbed and relaxed. Thus, the sheet hardly breaks upon heat forming. Moreover, since a sheet | seat does not break even during peeling (demolding) from a metal mold | die, it is easy to perform peeling (demolding) operation.

In addition, when the fabric sheet is embossed, since the fabric sheet has a rough surface, the anchor effect of the mold cleaning material is improved, and the adhesion between the fabric sheet and the mold cleaning material is increased.

1 is a perspective view showing a first embodiment of a sheet for reproducing a mold of the present invention.
2 is a perspective view showing a second embodiment of a sheet for reproducing a mold of the present invention.
3 is a perspective view showing a third embodiment of a sheet for reproducing a mold of the present invention.
4 (a) to 4 (g) are cross-sectional views showing modifications of the protruding line of the sheet for reproducing mold according to the present invention.
5 is a perspective view showing a fourth embodiment of a sheet for reproducing a mold of the present invention.

Next, embodiment of this invention is described more concretely based on drawing.

1 shows a first embodiment of a sheet for reproducing a mold of the present invention. The sheet for metal mold | die regeneration which concerns on this embodiment contains the base material sheet 1 formed from the paper sheet or the textile sheet, and the metal mold | die cleaning material which contains the unvulcanized rubber composition or the thermosetting resin composition on both surfaces of this base material sheet 1 Is formed in a strip-shaped pattern. That is, each of the protruding lines 2A, which is a component of the strip-shaped pattern, is arranged in parallel with an interval therebetween, and each gap serves as an air bleeding gap during the cleaning process of the mold. Moreover, the thin film 3 containing the said composition is integrally formed with the protruding line 2A in the surface part of the base material sheet 1 located in the air releasing space | gap part. Through the color tone or surface state of the thin film 3, the mixed state of the composition can be identified. As mentioned above, one of the main aspects of the present invention is directed to the formation of the thin film 3 which makes it possible to identify the mixed state of the composition of the mold cleaning material.

Specifically, the mold cleaning material and the composition of the thin film 3 (unvulcanized rubber-based composition or thermosetting resin-based composition) include unvulcanized rubber or thermosetting resin (main component), and inorganic filler such as silica powder or titanium dioxide mixed therewith. Include. Even if the inorganic filler is dispersed in an undissolved state, when the inorganic filler is uniformly dispersed, the thin film 3 exhibits a uniform color tone and a smooth surface. However, if the inorganic filler is unevenly dispersed, the thin film 3 exhibits uneven color tone. In addition, if the said inorganic filler is not disperse | distributed and it forms the lump, this lump part will appear as a convex part on the surface of the thin film 3. For example, in the case of a thermosetting resin-based composition, the thermosetting resin (main component) is generally colorless and transparent or translucent. When the inorganic filler is mixed with the thermosetting resin, the resultant mixture becomes white and opaque. However, if the inorganic filler is unevenly dispersed (mixed), the transparent or translucent part of the main component in the thin film 3 can be confirmed. The formation state of such a thin film 3 can be visually recognized.

Then, when the composition is identified as being uniformly mixed from the formation state of the thin film 3, the mold cleaning material of the protruding line 2A can be filled to every corner of the cavity. Therefore, cleaning can be performed to every corner of the cavity. On the other hand, in the case where the composition is identified as being mixed in a non-uniformly mixed state, the composition is not suitable for cleaning the mold and is not used for cleaning the mold.

More specifically, in view of easily identifying the mixed state of the composition appearing in the thin film 3, the thickness of the thin film 3 may be 500 μm, in particular in the range of 20 μm to 150 μm. If the thickness of the thin film is less than 20 μm, the thin film is too thin to identify the mixed state of the composition.

As described above, the composition is a mixture of an inorganic filler such as silica powder or titanium dioxide in an unvulcanized rubber or thermosetting resin. In particular, it is preferable to mix about 40-50 parts by weight of silica powder or about 5 parts by weight of titanium dioxide to 100 parts by weight of unvulcanized rubber or thermosetting resin. As needed, another component can be further suitably participated.

Specific examples of the unvulcanized rubber include natural rubber (NR), chloroprene rubber (CR), butadiene rubber (BR), nitrile rubber (NBR), ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), styrene butadiene Rubber (SBR), polyisoprene rubber (IR), isobutylene isoprene rubber (IIR), silicone rubber (Q), fluororubber (FKM) and the like.

Specific examples of the thermosetting resins include melamine resins and the like.

The method for producing a sheet for die regeneration includes, for example, kneading the composition with a continuous or batch kneader, and then disposing the composition on both sides of the base sheet 1. Next, the formed structure is sandwiched between two molds each having a strip-shaped pattern of the mold cleaning material and a recess corresponding to the thin film 3, and pressed. As a result, a strip | belt-shaped pattern and the thin film 3 are integrally formed in both surfaces of the base material sheet 1. As shown in FIG. Then, the formed structure is wound or cut into arbitrary dimensions. In this way, the sheet for die recycling can be produced.

In the above-mentioned embodiment, the thin film 3 is formed in the whole surface part of the base material sheet 1 located between 2A of protrusion lines of a strip | belt-shaped pattern. However, since the thin film 3 is used to identify the mixed state of the composition of the mold cleaning material as described above, it may be formed only on a part of the surface of the base sheet 1 between the protruding lines 2A.

In addition, although the above-mentioned embodiment includes simultaneously forming the strip | belt-shaped pattern and the thin film 3 through mold shaping | molding, it is also possible to form the thin film 3 by application | coating after carrying out the shaping | molding of a strip | belt-shaped pattern.

In the above-mentioned embodiment, the longitudinal direction of the protrusion line 2A of a strip | belt-shaped pattern is the same on the surface and the back surface of the base material sheet 1, respectively. However, as shown in FIG. 2, the longitudinal directions of the protruding lines of the band-shaped pattern on the front and back surfaces may be different from each other (eg, there is a difference of 90 ° in FIG. 2). As shown in FIG. 3, the band-like pattern and the thin film 3 may be formed only on one surface of the base sheet 1.

In addition, in the above-described embodiment, the cross-sectional shape in which the projecting lines 2A of the strip-shaped pattern are perpendicular to the longitudinal direction of the pattern is rectangular. However, any other cross sectional shape may be used. For example, a trapezoidal shape (eg, see FIG. 4A), a triangular shape (eg, see FIG. 4B), or a semi-circular shape (eg, FIG. 4C). May be used. In addition, the cross-sectional shape may be a dome shape at the top and a rectangle at the bottom thereof (for example, see FIG. 4D). In a variant, the cross-sectional shape may be a dome shape at its top and a trapezoidal shape at the bottom thereof (see, eg, FIG. 4E). In another variation, the cross-sectional shape may be a pentagonal shape with a top surface curved (see, eg, FIG. 4F). In still another modification, as shown in Fig. 4G, the top of the cross-sectional shape may be formed of a dome having a narrower width than the embodiment of Fig. 4D.

In particular, according to the embodiment shown in Figs. 4B to 4G, each of the top portions of the protruding lines 2A of the strip-shaped pattern is formed into a non-flat type. Therefore, even if the opening of the cavity is small, since the top part of the mold cleaning material partially blocks the opening, the air present in the cavity can be easily discharged. As a result, the filling property of the mold cleaning material is improved, and the cleaning property in the cavity is also improved. More specifically, in the embodiment shown in Figs. 4D to 4G, the radius of curvature of the top portion is 0.2 mm to 3.0 mm from the viewpoint of further improving the filling property of the mold cleaning material and the cleaning property in the cavity. It may be in the range of.

According to the embodiment described above, the mold cleaning material is formed of a strip pattern and a thin film 3. However, as shown in FIG. 5, the mold cleaning material may be formed into a viscous pattern and a thin film 3. Specific examples of the shape of each point 2B of the pointed pattern include cones, truncated cones, cylinders, prisms, pyramids, pyramids, and barrels in addition to the cylindrical shapes shown in FIG. 5. Although the embodiment of FIG. 5 has the viscous pattern and the thin film 3 only on one side of the base sheet 1, the viscous pattern and the thin film 3 may be formed on both sides of the base sheet 1.

According to the embodiment of FIGS. 1 and 2, the cleaning material is formed to have the same pattern on both surfaces of the base sheet 1. However, the patterns on both sides of the base sheet 1 may be different from each other. For example, the surface of the base material sheet 1 may have a strip | belt-shaped pattern, and the back surface may have a point-shaped pattern.

The dimension of the protrusion line 2A of a strip | belt-shaped pattern and the point 2B of a point-shaped pattern is set suitably according to the magnitude | size, arrangement | positioning, etc. of the cavity of a metal mold | die. Specifically, in the case of cleaning the transfer molding die used to seal the semiconductor element with resin, the width and thickness of each of the protruding lines 2A and the points 2B can be set in the range of 1 mm to 5 mm, The spacing between neighboring (opposing) projecting lines 2A and points 2B can be set in the range of 1 mm to 5 mm.

In order to optimize the balance between the volume of the air bleed voids and the amount of mold cleaning material, neighboring (opposing) protrusion lines 2A and spots 2B to optimize air bleeding and filling of the mold cleaning material in the cavity. The spacing between can be set to 0.5 to 2.0 times the width of each of the protruding lines 2A and points 2B. If the spacing between neighboring protruding lines 2A and points 2B is less than 0.5 times the width of the protruding lines 2A, when cleaning the mold, the openings of the cavity are formed in the protruding lines 2A or points 2B. As a result, air discharge from the cavity deteriorates and filling of the mold cleaning material becomes insufficient. In contrast, when the spacing between neighboring protruding lines 2A exceeds 2.0 times the width of the protruding lines 2A, the mold cleaning material may be distributed at a low density in the mold regeneration sheet, and as a result, the mold cleaning may be performed. Filling of the material becomes insufficient. In particular, the spacing between neighboring (opposing) protrusion lines 2A and points 2B may be set to have a cross-sectional area corresponding to 0.5 to 5 times the cross-sectional area of each of the protrusion lines 2A and points 2B. Can be.

In addition, from the viewpoint of stabilizing the shape of the protrusion line 2A and the point 2B to improve the filling property of the mold cleaning material, the width of each of the protrusion line 2A and the point 2B is 0.8 to 1.2 times the thickness thereof. It can be set to a range of times. If the width of each of the protruding lines 2A and the points 2B is less than 0.8 times the thickness thereof, the protruding lines 2A and the points 2B tend to be easily deformed. Therefore, when cleaning the mold, it is difficult to maintain the air bleeding voids, resulting in deterioration of air discharge from the cavity, and insufficient filling of the mold cleaning material. If the width of each of the protruding lines 2A and points 2B increases by more than 1.2 times its thickness, the openings of the cavity may be blocked by the mold cleaning material before the mold cleaning material is completely filled in the cavity, As a result, air discharge from the cavity becomes worse, and the filling of the mold cleaning material becomes insufficient.

Examples of the woven sheet of the base sheet 1 include a woven fabric, a nonwoven fabric, a knitted fabric, and the like. Of course, the woven fabric and the nonwoven fabric containing the long fibers have a moderately rough surface, thereby improving the anchoring effect of the protruding lines 2A, the dots 2B and the thin film 3, and the protruding lines 2A. Adhesion with) is enhanced (has grip property). In this respect, woven fabrics and nonwoven fabrics containing long fibers can be used, and in particular, nonwoven fabrics can be used in view of uniform grip. In addition, from the viewpoint of mechanical strength, uniformity and workability, a spunbond nonwoven fabric can be used as the nonwoven fabric. Also, since the embossed fabric sheet has a rough surface to enhance the anchor effect of the protruding line 2A, an embossed fabric sheet may be used. The base sheet 1 generally has a thickness in the range of 0.1 mm to 0.8 mm.

Example

Next, an Example and a comparative example are demonstrated. However, the present invention is not limited to these embodiments.

(Fabric sheet)

As a base sheet, the spunbond nonwoven fabric (commercially available from Asahi Kasei Co., Ltd. E01070) formed from polyester long fiber was prepared. This nonwoven fabric had a tear strength of 8.5 N, a thickness of 0.35 mm, and a basis weight of 70 g / m 2.

(Mold cleaning material)

First, 100 parts by weight of ethylene propylene rubber, 50 parts by weight of silica powder, 5 parts by weight of titanium dioxide, 2 parts by weight of organic peroxide [n-butyl-4,4-bis (t-butylperoxy) valerate], imidazole { 10 parts by weight of 2,4-diamino-6- [2'-methylimidazolyl- (1 ')] ethyl-s-triazine} and 5 parts by weight of montan wax were prepared.

Next, the above components were mixed and kneaded with a kneader. For comparison, a mold cleaning material prepared by sufficiently kneading and a mold cleaning material prepared by insufficiently kneading were prepared separately.

(Production of sheet for mold reproduction)

Two base sheets were prepared, and the mold cleaning material prepared by sufficiently kneading the above was attached to both surfaces of one base sheet. In addition, the mold cleaning material prepared by insufficiently kneading the above was attached to both surfaces of another base sheet. Each metal mold | die cleaning material was formed in the strip | belt-shaped pattern (5 mm of space | interval of protrusion line) which has a rectangular cross section (5 mm in width x 3 mm in height), and was formed in thin film (100 micrometers in thickness). In this way, two sheets for mold regeneration were obtained.

(Identifying Sheet for Mold Reproduction)

The two sheets for die regeneration were visually inspected for the state of thin film formation. The thin film of the sheet | seat using the metal mold | die cleaning material prepared by the said kneading | mixing fully showed uniform color tone. On the other hand, the thin film of the sheet | seat using the metal mold | die cleaning material prepared by performing the said kneading | mixing insufficiently showed uneven hue.

As can be seen from the above, the mold cleaning material prepared by sufficiently kneading the mixture appears to have a uniform mixing state, but the mold cleaning material prepared by insufficiently kneading the mixture shows that the composition of the composition is uneven.

(Cleaning property)

Using the two sheet | seats for metal reproduction | regeneration, the transfer molding metal mold | die used for sealing a semiconductor element with resin was performed. As a result, the sheet | seat using the metal mold | die cleaning material prepared by fully kneading | mixing the said metal mold | die was cleaned to every corner of a cavity. On the other hand, the sheet | seat using the metal mold | die cleaning material prepared by performing the said kneading | mixing inadequate was not able to clean to every corner of a cavity.

As can be seen from the above, the mold cleaning material prepared by sufficiently kneading the mixture appears to have excellent filling (cleaning) properties in the cavity, but the mold cleaning material prepared by insufficiently kneading the mixture has poor filling (cleaning properties). Appears to be not.

(Comparative Example)

In the same manner as in the above example, two mold recycling sheets were obtained using a mold cleaning material having a different kneaded state. However, in this comparative example, only a strip | belt-shaped pattern was formed without forming a thin film. Thus, the substrate sheet was exposed between the adjacent protruding lines of the strip pattern.

Although the protrusion line of the strip | belt-shaped pattern of a comparative example was visually examined, the kneading state of the metal mold | die cleaning material was not able to be distinguished.

Therefore, from the above result, it can confirm that the thin film of the said Example is effective for identifying the mixed state of the composition of metal mold | die cleaning material.

In addition, in the said Example, although the thickness of the thin film was 100 micrometers, when the thickness of the thin film was 20 micrometers, 150 micrometers, and 500 micrometers, the result of the same tendency was obtained.

In addition, in the said Example, although the unvulcanized rubber-type composition was used as a metal mold | die cleaning material, even when the thermosetting resin type composition containing a melamine resin as a main component was used, the progress of the same tendency was obtained.

While the invention has been described in detail with reference to specific embodiments thereof, it will be apparent to those skilled in the art that various changes and modifications can be made to the embodiments without departing from the spirit and scope of the invention.

By the way, this application is based on Japanese Patent Application No. 2011-178946 for which it applied on August 18, 2011, The content of this patent application is integrated in this application by reference.

All references cited herein are hereby incorporated by reference in their entirety.

The sheet for regenerating the mold according to the present invention makes it possible to visually identify the mixed state of the composition of the mold cleaning material, so that only high quality products can be used to clean the cavity surface of the mold.

1: base material sheet
2A: Extrusion Line
3: thin film

Claims (11)

Paper sheets or fabric sheets; And
A mold cleaning material comprising an unvulcanized rubber-based composition or a thermosetting resin-based composition and formed on at least one side of the paper sheet or fabric sheet to protrude in a predetermined pattern having air bleed pores.
And a thin film comprising the composition is formed on the surface portion of the paper sheet or the fabric sheet positioned in the air venting air gap portion, and a mixed state of the composition forming the pattern is a formation state of the thin film. A sheet for regenerating a mold, which can be identified from. The sheet for reclaiming mold according to claim 1, wherein the thin film has a thickness of 500 μm or less. The die recycling sheet according to claim 1 or 2, wherein the pattern has a non-flat top. 4. The sheet for reclaiming metal mold according to claim 3, wherein the non-flat top is formed by a convex portion having a radius of curvature in the range of 0.2 mm to 3.0 mm. The sheet for reclaiming metal mold according to claim 1 or 2, wherein the pattern is formed of a plurality of bands or a plurality of dots. 6. The mold regeneration of claim 5, wherein the strips or spots have a width and thickness in the range of 1 mm to 5 mm, respectively, and the spacing between neighboring strips or spots is set in the range of 1 mm to 5 mm. Sheet. 6. The sheet for reclaiming metal mold according to claim 5, wherein an interval between the adjacent bands or dots is set to 0.5 to 2.0 times the width of the bands or dots. 6. The sheet for reclaiming metal mold according to claim 5, wherein the width of the strip or dot is set to 0.8 to 1.2 times the thickness of the strip or dot. The sheet for reclaiming mold according to claim 1 or 2, wherein the fabric sheet is a nonwoven fabric. 10. The sheet for reclaiming mold according to claim 9, wherein the nonwoven fabric is a spunbond nonwoven fabric. The sheet for reclaiming metal mold according to claim 1 or 2, wherein the fabric sheet is embossed.

Images