JP2007195785A - Cup - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cup creating rich foaming when pouring beer or the like without forming cuts by sandblast or laser. <P>SOLUTION: Approximately concentric annuli 21 or an approximately spiral belt is formed from the side of the inner bottom 12 toward the side of an opening part 13 of the cup with either of an ink brush or a brush, polyurethane resin, or thermosetting resin, is applied to a part of the inner surface of the cup to form a resin film layer, the thickness of the resin film layer is defined to 1-50 μm, fine pores are developed in the resin film layer, and 500-20,000 fine pores with the diameter of 1-50 μm are formed per 1 mm<SP>2</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cup, and more particularly to a beer cup that produces good foam retention such as beer.

  The fine foam blocks the outside air from the beer in the glass, and it contains beer aroma and prevents beer oxidation. Therefore, it is indispensable for maintaining the flavor of beer. In addition, due to the fine foam feel, peculiar taste can be obtained when it is contained in the mouth.

  In general, foaming when beer or the like is poured into a cup is known to cause the beer to come into contact with fine irregularities on the inner surface of the cup and to release supersaturated carbon dioxide gas in the beer due to the impact.

  Conventionally, various improvements have been made in order to improve foaming when beer is poured. As one of them, a cup in which the whole material is porous like unglazed ware is commercially available. However, unglazed cups cannot enjoy the color of beer, and it is inevitable that interest will decline.

  Therefore, a method has been attempted in which transparent glass is used in place of unglazed baking and fine irregularities are formed on the inner surface. For example, a beer mug has been proposed in which the inner surface of a mug is sandblasted to form fine irregularities (see Patent Document 1). Further, a cup has been proposed in which fine irregularities are formed by irradiating a carbon dioxide laser on the inner bottom surface of the cup (see Patent Document 2).

According to the beer mug disclosed in Patent Document 1, the mug itself becomes opaque because of sandblasting. Therefore, if the sandblasting method is applied to a cup as it is, it becomes a sultry cup and does not look good. Further, in common with Patent Documents 1 and 2, scratches are provided on the glass on the inner surface and the inner bottom surface of the cup in order to form fine irregularities. In general, it is known that the strength of glass and ceramics is inversely proportional to the square root of the depth of surface flaws. Therefore, a processing method for directly scratching the glass surface is not preferable from the viewpoint of maintaining strength.
JP-A-8-242999 JP 2003-61804 A

  This invention is made | formed in view of the said point, and provides the cup which produces rich foaming when pouring beer etc., without damaging a cup by sandblasting or a laser.

  That is, the invention of claim 1 relates to a cup characterized in that a resin film layer is formed by applying a resin to the inner surface of the cup.

  According to a second aspect of the present invention, the resin film layer is formed on a part of the inner surface of the cup by forming a substantially concentric ring from the inner bottom surface side to the opening side of the cup. 1. The cup according to 1.

  According to a third aspect of the present invention, the resin film layer is formed on a part of the inner surface of the cup by forming a substantially spiral band from the inner bottom surface side to the opening side of the cup. 1. The cup according to 1.

  The invention according to claim 4 relates to the cup according to any one of claims 1 to 3, wherein the resin film layer is formed by applying the resin with a brush or a brush.

  The invention according to claim 5 relates to the glass according to any one of claims 1 to 4, wherein the resin is a thermosetting resin and a polyurethane resin.

  The invention according to claim 6 relates to the glass according to any one of claims 1 to 5, wherein the resin film layer has a thickness of 1 to 50 μm.

The invention according to claim 7 relates to the glass according to claim 6, wherein pores are formed in the resin film layer, and 500 to 20000 pores having a pore diameter of 1 to 50 μm exist per 1 mm ^2. .

  According to the cup according to the invention of claim 1, since the resin film layer is formed by applying the resin to the inner surface of the cup, it causes rich foaming when beer is poured without damaging the cup. Can do.

  According to the cup of the invention of claim 2, in the invention of claim 1, the resin film layer forms a substantially concentric ring from the inner bottom surface side of the cup toward the opening side. Since the beer is poured into the glass, the beer directly contacts the substantially concentric ring. In addition, as the liquid level rises when a glass of beer is poured, the beer is repeatedly subjected to physical shocks by being repeatedly contacted with the substantially concentric ring, and dissolved. The supersaturated carbon dioxide gas that has been generated is generated as small bubbles and is likely to rise. Therefore, the duration of foam generated when pouring beer or the like can be made longer.

  According to the cup of the invention of claim 3, in the invention of claim 1, the resin film layer forms a substantially spiral band from the inner bottom surface side of the cup toward the opening side. Since the beer is poured into a glass, the beer directly comes into contact with the spiral band. In addition, as the liquid level rises when a glass of beer is poured, the beer comes in contact with the approximately spiral band many times, so that the beer is subjected to physical shock many times and dissolved. The supersaturated carbon dioxide gas that has been generated is generated as small bubbles and is likely to rise. Therefore, the duration of foam generated when pouring beer or the like can be made longer.

  According to the cup of the invention of claim 4, in the invention of any one of claims 1 to 3, since the resin is a thermosetting resin and a polyurethane resin, the impact and friction during cleaning are reduced. In addition to the durability, heat resistance can be provided, and the function of the resin film layer can be maintained.

  According to the cup of the invention of claim 5, in the invention of any one of claims 1 to 4, the resin film layer is formed by applying the resin with either a brush or a brush. Therefore, the air around the tip of the hair is entangled in the resin, the coating of the resin deposited by the tip of the brush becomes rough, and the impact received by the beer from the resin film layer when the beer is poured is increased. Can do.

  According to the cup according to the invention of claim 6, in the invention according to any one of claims 1 to 5, since the resin film layer has a layer thickness of 1 to 50 μm, the impact resistance of the resin film layer itself And the resin film layer on the inner surface of the cup becomes inconspicuous.

According to the cup according to the invention of claim 7, in the invention of claim 6, pores are formed in the resin film layer, and pores having a pore diameter of 1 to 50 μm are 500 to 1 mm ² . Since there are 20000, suitable fine bubbles can be generated, and good foaming can be realized.

The present invention will be described below with reference to the accompanying drawings.
1 is an overall perspective view of a cup according to one embodiment of the present invention, FIG. 2 is an overall perspective view of a cup according to another embodiment, FIG. 3 is a first schematic view showing application of resin, and FIG. FIG. 5 is a conceptual diagram of foaming, showing a second schematic diagram showing application.

  The cup of the present invention is a beer cup having a characteristic of causing moderate foaming when beer is poured. The cup is made of glass or a heat-resistant known resin material. In any case, it is preferable to be transparent in order to enjoy the color of beer. The beer includes beer, sparkling liquor, miscellaneous liquor, and other beer-taste beverages with an alcohol concentration of less than 1%, all of which dissolves dissolved gas (carbon dioxide, etc.) It is characterized by. Furthermore, alcoholic beverages such as sparkling wine and beverages such as cider can also be included. Hereinafter, these drinks are collectively referred to as beer.

  In order to produce fine foaming as well as when beer is poured, the resin film layer 20 is formed by applying a resin to the inner surface 11 of the cup 10 as shown in FIG. Is forming.

  Focusing on the resin film layer 20 of the cup 10, as defined in the invention of claim 2, the resin film layer 20 has a substantially concentric ring 21 formed from the inner bottom surface 12 side of the cup 10 toward the opening 13 side. Formed. Further, as shown in FIG. 2 and as defined in the invention of claim 3, in the cup 10A, the resin film layer 20A is formed in a substantially spiral shape from the inner bottom surface 12 side to the opening 13 side of the cup 10A. A band 22 is formed.

  As can be understood from FIGS. 1 and 2, the resin film layers 20 and 20 </ b> A made of resin applied to the inner surface 11 of the cup 10, 10 </ b> A have a linear shape (band shape) on a part of the inner surface 11 of the cup. Formed. That is, a step is generated on the inner surface 11 of the cup by the resin film layers 20 and 20A. For this reason, when the beer is poured into a glass, or when the liquid level of the poured beer rises, the beer is sequentially arranged with a substantially concentric ring 21 or a substantially spiral band 22. Touch again. Due to the contact, the beer is subjected to physical impacts many times, and the supersaturated carbon dioxide gas dissolved in the beer is generated as small bubbles and easily rises.

  Of course, the number of the substantially concentric rings 21 in the cup 10 and the number, width, and shape of the substantially spiral band 22 in the cup 10A are the size, design, desired foaming condition, and type of beer itself. It is appropriate depending on the situation. Further, the substantially concentric ring 21 and the substantially spiral band 22 may be a continuous shape as shown in the figure or a shape interrupted in the middle of the figure. As is obvious from the drawing, a substantially spiral band can be drawn with a single stroke as compared with a substantially concentric ring, so that the work efficiency of resin coating is good.

  Various methods are considered for forming the resin film layer on the inner surface of the cup. For example, spray coating, dropping with a dropper, or the like. However, according to the verification by the inventors, it is desirable that the resin film layer is formed by applying the resin with either a brush or a brush as defined in the invention of claim 4.

  FIG. 3 schematically shows a state of application of the resin R using dropping by a dropper. FIG. 3A shows before application, FIG. 3B shows application in progress, and FIG. 3C shows application completion. That is, the resin R flowing out from the tip 31 of the dropper 30 is directly deposited on the inner surface 11 of the cup, and becomes a resin layer film after subsequent drying.

  On the other hand, FIG. 4 schematically shows how the resin R is applied with a brush. FIG. 4A shows before application, FIG. 4B shows the application in progress, and FIG. 4C shows the completion of application. The resin contained in the hair tip 41 of the brush 40 is also deposited on the inner surface 11 of the cup. In this case, it is assumed that the air around the tip of the brush is caught in the resin while the resin flows along the tip of the brush. Moreover, the coating mark of the resin deposited by the brush tip becomes rough. In addition, it is considered that a porous resin film layer is formed through subsequent drying. As a result, an increase in impact received when pouring beer is presumed. In addition, since the brush has the same structure as the brush in that it has a hair tip, the description and illustration thereof are omitted.

  The resin that is applied to the inner surface of the cup has weather resistance that does not deteriorate in the air, as well as impact and heat resistance that can withstand the impact of washing and handling of the cup, heat during washing, and washing liquid. It is necessary to satisfy the chemical resistance as much as possible and continue to maintain the function of the resin film layer. Therefore, the resin types that can be applied include, as specified in the invention of claim 5, resin types such as a thermosetting resin polyurethane resin, a thermosetting resin epoxy resin, a phenol resin, and a melamine resin. Is available.

  After the resin is applied to the inner surface of the cup, it is heated under a temperature atmosphere corresponding to the resin type. For example, in the case of a polyurethane resin as a thermosetting resin, the heating temperature is set to 150 to 220 ° C. When the temperature is 150 ° C. or lower, thermosetting does not proceed and the durability of the resin film layer is insufficient. Moreover, when it is 220 degreeC or more, since there exists a possibility of producing discoloration of resin, it is unpreferable.

  The thickness of the resin film layer formed by applying a resin to the inner surface of the cup is preferably 1 to 50 μm as defined in the invention of claim 6. When the layer thickness of the resin film layer is extremely thin such as 1 μm or less, the impact resistance and wear resistance of the resin film layer itself are lowered. Although the upper limit is appropriate, even if it exceeds 50 μm, the improvement of the foaming effect cannot be expected so much. In consideration of the fact that the cup is made of transparent glass, the resin film layer on the inner surface of the cup is conspicuously recognized due to the increase in the thickness of the resin film layer. Also from such a viewpoint, the layer thickness of the resin film layer is set to 50 μm or less. Incidentally, if the refractive index of the formed resin film layer is 1.7 or less, it is considered difficult to recognize in appearance.

  In addition, about the resin film layer formed by apply | coating resin to the inner surface of a cup, an appropriate hydrophilization process is performed if necessary. For example, plasma treatment, corona discharge, chemical treatment, ozone treatment and the like. As a result, the polarity of the surface of the resin film layer is changed and the hydrophilicity is increased.

The resin film layer formed on the inner surface of the cup has pores as defined in the invention of claim 7. There are 500 to 20000 pores having a pore diameter (pore diameter) of 1 to 50 μm per 1 mm ^{2 of the} resin film layer surface. These pores are formed by volatilization of the solvent component when the resin is cured. For example, in the case of a water-soluble thermosetting polyurethane resin, moisture is evaporated during heating and curing, resulting in pores. When the pore diameter is extremely small, the generation of bubbles is not affected. When it becomes larger than the thickness of the resin film layer, it does not function as a step due to the pores, and the bubble tends to become large and the sustainability of the bubble may be lowered. The existence frequency per unit area of the pores is based on a non-defective product prototype, as will be understood from examples described later.

  The pores formed in the resin film layer are, in particular, bubbles generated by air entrained in the resin by brush coating or brush coating, which are destroyed when the resin is thermally cured and dried. It is thought that hemispherical depression occurred. In the examples, the number of pores and the like are confirmed by imaging with an electron microscope.

  Here, the pores formed in the resin film layer and the foaming of beer are conceptually shown in the schematic cross-sectional view of FIG. According to FIG. 5A, pores 25 are formed in the resin film layers 20 and 20A deposited on the inner surface 11 of the cups 10 and 10A. The layer thickness T of the resin film layer is 1 to 50 μm as described above. The diameter of the pores (pore diameter D) is also 1 to 50 μm. The surface 24 of the resin film layer approximates a porous state like an unglazed container.

  Next, when beer is poured, as shown in FIG. 5B, the beer Lq comes into contact with the pores 25 while passing through the resin film layers 20 and 20A. Due to the impact at this time, the beers are destabilized from the equilibrium state, and the dissolved carbon dioxide (carbon dioxide) is released to produce the fine bubbles 30. Thus, the generated fine foam rises to become a foam unique to beer that is beautiful and tasty on the liquid surface.

[Materials used]
As a cup, a glass cup “small cup 6” manufactured by Ishizuka Glass Co., Ltd .: a capacity of 180 mL, an opening diameter of 60 mm, and an overall height of 93 mm was used. Here, the said glass cup "small cup 6" which has not performed any process was made into the comparative example. As the beer, beer “Asahi Super Dry” manufactured by Asahi Breweries was used.

  The cups of the following comparative examples and prototypes were washed with warm water of 40 ° C. or higher using a commercial household dish detergent and dish sponge, and the inner surface of the cup was rinsed with tap water and distilled water. Further, after the distilled water was filled to the full volume of the cup, the distilled water was discarded, and drained for 60 seconds with the cup lying down. The beer was left unopened and the liquid temperature was kept at 10 ° C. Immediately after opening, 80 mL was poured into a conical beaker and weighed, and then poured into a cup that had been drained for 60 seconds. The resulting foam on the beer liquid surface was evaluated. When pouring beer into a glass and immediately after pouring, an outline can be shown as shown in FIGS. 6 (a) and 6 (b). Symbol B is beer foam, and Lq is beer.

[Evaluation methods]
The bubble retention time indicates the time until a portion where bubbles are not present, that is, a portion of the liquid level of beer is exposed as the bubbles are reduced in the bubbles generated by pouring beer. This situation is referred to as the exposed beer liquid level Ls in FIG. The glass foam “small cup 6” itself, which is a non-treated cup (comparative example), has the bubble retention time as a reference time, and how long the bubble retention time of each prototype is longer than the reference time. It measured about.

  The evaluation of foaming is an evaluation of the presence or absence of a portion (point) causing foaming from the inner surface of the cup after pouring beer into the cup, and the number and foaming state. Evaluation was made in the following three stages by visual inspection. “◎” indicates a state in which bubbles are continuously generated from two or more locations on the inner surface of the cup. In “◯”, bubbles are continuously generated from one place on the inner surface of the cup. Or it is the state which is generating the bubble discontinuously although it is two or more places. “△” indicates no foaming from the inner surface of the cup. Or it is the state where generation | occurrence | production of a discontinuous bubble exists in one place.

  The evaluation with foam on the inner surface is an evaluation as to how much foam remains on the inner surface of the cup in each cup at the time when the measurement of the bubble holding time is finished. This is referred to as a bubbled portion Br marked with “*” in FIGS. 6 (c) and 6 (d). Evaluation was made into the following two stages by visual observation. “◯” indicates a state in which bubbles still adhere to an inner surface area of more than half compared with the inner surface of the cup filled with the initial bubbles shown in FIG. “Δ” indicates a state where the adhering bubbles are less than half of the inner surface area.

  The expression “with foam on the liquid surface” is an evaluation regarding whether or not foam remains between the liquid surface Ls of beer and the inner surface of the cup in each cup when the measurement of the foam holding time is finished. Therefore, it is assumed that “◯” indicates that the part Bs with the liquid level bubble marked with “#” in FIG. 6C exists. “×” indicates that the liquid level foamed portion Bs is not seen, and the liquid level of the foam and the beer is separated as shown in FIG.

  For repeated resistance, a commercially available cup cleaning sponge was used and the inner surface of the prototype cup was repeatedly rubbed 10,000 times. Then, the presence or absence of peeling of the resin film layer formed on the inner surface of the cup was observed. “◯” indicates no peeling, “Δ” indicates partial peeling, and “×” indicates all peeling.

[Formation of resin film layer]
The difference in pore distribution and foaming due to the difference in the resin film layer formation method was verified.

  In Prototype Example 1, the water-soluble polyurethane resin PU-1 was applied to the inner surface of the cup of the comparative example in a spiral shape with a dropper, and then the inner surface of the cup was etched using hydrogen fluoride (hydrofluoric acid water). It is a cup in which the polyurethane resin has disappeared by heating the cup at 600 ° C. for 5 hours. In this case, since the resin portion is not corroded by hydrofluoric acid, a substantially spiral step is formed on the inner surface of the cup. According to Prototype Example 1, the etching depth was 8 μm. The water-soluble polyurethane resin PU-1 has a volatile water content of 60%.

  In Prototype Example 2, the polyurethane resin PU-1 was similarly applied to the inner surface of the cup of the comparative example in a spiral shape with a dropper, heated at 170 ° C. for 20 minutes, and subjected to a hydrophilic treatment on the resin film layer after thermosetting. It is a cup. The step (layer thickness) of the resin film layer of Prototype Example 2 was 15 μm.

  In Prototype Example 3, the polyurethane resin PU-1 was applied to the inner surface of the cup of Comparative Example in a spiral shape with a brush, heated at 170 ° C. for 20 minutes, and subjected to hydrophilic treatment on the resin film layer after thermosetting. It is a cup. The step (layer thickness) of the resin film layer of Prototype Example 3 was 8 μm.

For Comparative Examples and Prototype Examples 1 to 3, the pore distribution, pore diameter, and foaming time were measured and observed. The results are in Table 1. The pore distribution was converted to the number of pores per unit area of 1 mm ² using a scanning electron microscope (SEM). Foaming time indicates the time difference from the comparative example.

Looking at the pore distribution, Comparative Example and Prototype Example 1 are observations of the glass ground itself on the inner surface of the cup, so the number of pores is zero. On the other hand, according to prototype examples 2 and 3, the number of pores increases. In particular, as can be seen from Prototype Example 4, the number of pores increases significantly by brush painting. This is presumed that air was caught in the brush tip and bubbles were formed in the resin. When the effect of increasing the bubble holding time is compared, Prototype Example 4 is the best. That is, as the number of pores increases, good foaming and foam retention are induced. Considering these, it is preferable that 500 to 20000 pores having a pore diameter of 1 to 50 μm exist per 1 mm ² . In addition, as in Prototype Example 1, the effect of foam retention cannot be expected with only a level difference, that is, the unevenness of the glass.

  Subsequently, the state of bubbles when various resins were applied including the conventional method was evaluated.

  Prototype Example 4 is a cup obtained by injecting glass beads of # 400 for 30 seconds at an injection pressure of 0.75 MPa on the inner surface of the cup of the comparative example, and performing a sandblast treatment.

  Prototype Example 5 is a cup that was coated with polyurethane resin PU-1 on the entire inner surface of the comparative cup and heated at 170 ° C. for 20 minutes.

  Prototype Example 6 is a cup obtained by heating the cup of the comparative example to 120 ° C. and spray-coating a water-soluble polyethylene resin on the inner surface of the cup.

  Prototype Example 7 is a cup in which polyurethane resin PU-1 is applied in a substantially spiral shape with a brush on the inner surface of a comparative example cup and heated at 170 ° C. for 20 minutes.

  In Prototype Example 8, the polyurethane resin PU-2 was applied to the inner surface of the comparative cup in a spiral shape with a brush, heated at 170 ° C. for 20 minutes, and subjected to hydrophilic treatment on the resin film layer after thermosetting. It is a cup.

  In Prototype Example 9, the polyurethane resin PU-3 was applied to the inner surface of the comparative cup in a spiral manner with a brush, heated at 170 ° C. for 20 minutes, and subjected to hydrophilic treatment on the resin film layer after thermosetting. It is a cup.

  In Prototype Example 10, the polyurethane resin PU-4 was applied to the inner surface of the comparative cup in a spiral shape with a brush, heated at 170 ° C. for 20 minutes, and subjected to hydrophilic treatment on the resin film layer after thermosetting. It is a cup.

  Table 2 shows the results of the comparative example and the prototype examples 4 to 10 with respect to foam retention time, foaming, inner surface foaming, liquid surface foaming, and repeated effects.

  As the result of Prototype Example 4, according to the treatment accompanied by the sand blasting in Patent Document 1 disclosed in Background Art, the foam retention and the foam residue are bad. In the case of the thermoplastic resin as in Prototype Example 6, although the foam retention and foaming are good, the repeated resistance is not good and practical application is difficult.

  In the case where the resin film layer is formed on the entire inner surface of the cup as in Prototype Example 5, foam retention is not expected. With respect to this factor, the number of pores increases with an increase in the formation area of the resin film layer. However, resistance due to a step between the inner surface of the cup and the resin film layer when the beer liquid level rises is eliminated. As a result, it is assumed that the impact received by the beer itself poured into the cup has been reduced. Therefore, it is desirable to form the resin film layer on a part of the inner surface of the cup in consideration of foam formation.

  About the example 3 of trial manufacture and the examples 7 thru | or 10 of an experiment, although the fluctuation | variation by the kind of polyurethane resin is seen, all items are favorable generally. Therefore, application of the resin should be limited to a part of the inner surface of the cup. The resin is preferably a polyurethane resin which is a thermosetting resin in consideration of durability.

[Layer thickness and curing temperature]
In order to change the layer thickness of the resin film layer formed on the inner surface of the cup, the polyurethane resin PU-1 was applied while sequentially changing the coating amount. Moreover, the influence by the thermosetting temperature for each layer thickness was also evaluated. The following Tables 3 to 6 show the appearance of repeated resistance and visual appearance when the layer thickness and the thermosetting temperature are changed. The thermosetting temperature in Table 3 is 140 ° C., the thermosetting temperature in Table 4 is 170 ° C., the thermosetting temperature in Table 5 is 200 ° C., and the thermosetting temperature in Table 6 is 230 ° C. In the appearance of visual appearance in the table, “◯” is colorless and transparent and normal. “△” indicates slight yellowing, and “x” indicates considerable yellowing. Furthermore, the addition of “-” indicates that the presence of the resin film layer was visually recognized.

  As can be seen from Tables 3 to 6, when the thermosetting temperature is 140 ° C. (Table 3) and 230 ° C. (Table 6), there is a problem in repeated resistance or appearance. Therefore, considering a suitable thermosetting temperature range, it is 150-220 degreeC, More preferably, it is 170-200 degreeC. Next, when paying attention to the layer thickness, repeated resistance decreases at the thinnest layer thickness in any table. Of course, the repeated resistance improves as the layer thickness increases. However, since the presence of the resin film layer is revealed, it is not preferable if importance is attached to the beauty as a glass cup. Therefore, it is desirable that the resin film layer has a thickness of 1 to 50 μm, more preferably 5 to 50 μm. Since the same tendency is applied to other polyurethane resins and the like, the above layer thickness is presumed to be suitable.

1 is an overall perspective view of a cup according to an embodiment of the present invention. It is a whole perspective view of the cup concerning other examples. It is a 1st schematic diagram which shows application | coating of resin. It is a 2nd schematic diagram which shows application | coating of resin. It is a conceptual diagram of foaming. It is the schematic of foaming evaluation.

Explanation of symbols

10,10A cup (cup for beer)
DESCRIPTION OF SYMBOLS 11 Inner surface 12 Inner bottom face 13 Opening part 20,20A Resin film layer 21 Substantially concentric ring 22 Substantially spiral band 25 Pore 30 Fine bubble 40 Brush 41 Tip

Claims (7)

  A cup characterized in that a resin film layer is formed by applying a resin to the inner surface of the cup.   The cup according to claim 1, wherein the resin film layer is formed on a part of the inner surface of the cup by forming a substantially concentric ring from the inner bottom surface side to the opening side of the cup.   The cup according to claim 1, wherein the resin film layer is formed on a part of the inner surface of the cup by forming a substantially spiral band from the inner bottom surface side of the cup toward the opening side.   The cup according to any one of claims 1 to 3, wherein the resin film layer is formed by applying the resin with either a brush or a brush.   The cup according to any one of claims 1 to 4, wherein the resin is a thermosetting resin and a polyurethane resin.   The cup according to any one of claims 1 to 5, wherein the resin film layer has a thickness of 1 to 50 µm. The cup according to claim 6, wherein pores are formed in the resin film layer, and 500 to 20000 pores having a pore diameter of 1 to 50 µm exist per 1 mm ² .

Images