Humidity indicator card comprising electrically conductive carbon body and method of making same

Abstract

The present invention relates to a humidity indicator card comprising blotting paper, anti-static layers on the upper and lower parts of the blotting paper, and a humidity indicator part on one surface of the anti-static layers, the anti-static layers comprising an anti-static composition containing conductive carbon black, and the humidity indicator part comprising 100 parts by weight of the anti-static composition, the conductive carbon black containing 1-30 parts by weight of the conductive carbon black can provide an excellent antistatic effect.

Description

Technical Field

[0001] The present invention relates to a humidity indicator card comprising a conductive carbon body and a method for manufacturing the same. Background Art

[0002] Humidity indicator cards are products that can easily confirm changes in relative humidity because the humidity indicator changes color as the relative humidity changes. They can be packaged together with humidity-sensitive semiconductor chips, printed circuit boards (PCBs), and precision electronic devices. When the packaged product is opened, the color change of the humidity indicator card can be easily judged to determine whether the product is stable to moisture.

[0003] However, when the integrated circuit device and the humidity indicator card are sealed together, electrostatic discharge (ESD) may occur due to friction generated when the humidity indicator card contacts the device.

[0004] In particular, in the case of an integrated circuit device having a size of several hundred nanometers, electrostatic discharge is applied in a short time per unit area (1 μm 2 ) During the period of voltage of hundreds to thousands of V, serious damage to the device is caused, and serious problems such as fire and explosion may occur. Therefore, it is necessary to study a humidity indicator card that can prevent the electrostatic discharge phenomenon that causes serious defects in the device. Summary of the invention

[0005] The object of the present invention is to solve the problems of the conventional technology, and to provide a humidity indicator card with an antistatic function and a method for manufacturing the same.

[0006] The humidity indicator card with an antistatic function according to the present invention comprises blotting paper, antistatic layers located at the upper and lower parts of the blotting paper, and a humidity indicating part located on one side of the antistatic layer, wherein the antistatic layer comprises an antistatic composition containing conductive carbon black, and contains 1 to 30 parts by weight of the conductive carbon black based on 100 parts by weight of the antistatic composition.

[0007] In one embodiment, the antistatic composition may further include a binder and a solvent.

[0008] In one embodiment, the binder may include a rosin-based resin.

[0009] In one embodiment, the solvent may include vegetable oil.

[0010] In one embodiment, the specific surface area of ​​the conductive carbon black may be 50 to 100 m 2 / g.

[0011] In one embodiment, the oil absorption number (OAN) of the conductive carbon black may be 100 to 300 ml / 100 g.

[0012] In one embodiment, the conductive carbon black may contain less than 300 ppm of sulfur.

[0013] In one embodiment, the hygroscopicity of the blotting paper may be 40 to 200 seconds.

[0014] In one embodiment, the thickness of the blotting paper may be 400 to 500 μm.

[0015] In one embodiment, the surface resistance of the humidity indicator card may be 10 3 Up to 10 7 Ω / sq.

[0016] In one embodiment, the antistatic composition may further include a polypyrrole-based polymer.

[0017] In one embodiment, the humidity indicator may not include an antistatic composition.

[0018] The method for manufacturing a humidity indicator card with an antistatic function added according to the present invention comprises: (S10) applying an antistatic composition containing conductive carbon black to the upper and lower parts of blotting paper to form an antistatic layer; (S20) forming a humidity indicator portion on one side of the antistatic layer to manufacture a humidity indicator card; and (S30) drying the humidity indicator card, wherein the conductive carbon black is contained in an amount of 1 to 30 parts by weight based on 100 parts by weight of the antistatic composition.

[0019] In one embodiment, in the step (S30), the drying temperature may be 40 to 100°C.

[0020] In one embodiment, in the step (S10), the antistatic composition may be applied to a region other than the humidity indicator region.

[0021] In one embodiment, after the step (S10), the method may further include: (S15) cutting the blotting paper including the antistatic layer.

[0022] In one embodiment, after the step (S30), the method may further include: (S40) a step of sealing the dried humidity indicator card.

[0023] The humidity indicator card according to the present invention has an anti-static function, so that the products packaged together with the humidity indicator card can be protected from damage caused by static electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a diagram showing a humidity indicator card according to an embodiment.

[0025] Figure 2 is a sequence diagram showing a method for manufacturing a humidity indicator card according to an embodiment.

[0026] Figure 3 is a diagram showing an ink-blotting paper printed with an antistatic layer according to an embodiment.

[0027] Figures 4 to 7 is a diagram showing a humidity indicator card according to an embodiment.

[0028] Description of Reference Numerals

[0029] 10: Ink blotting paper 20: Antistatic layer

[0030] 30: Humidity indicator unit 100: Humidity indicator card DETAILED DESCRIPTION

[0031] The humidity indicator card including the conductive carbon body and the manufacturing method thereof of the present invention are described in detail. The terms used in this specification are selected as general terms that are currently widely used as much as possible in consideration of the functions of the present invention, but they may be different according to the intentions or precedents of technicians in the relevant field, the emergence of new technologies, etc. Regarding the technical terms and scientific terms used, unless otherwise defined differently, they may have the meanings generally understood by ordinary technicians in the technical field to which the present invention belongs.

[0032] In this specification and the appended claims, terms such as “including” or “having” mean the presence of features or constituent elements recorded in the specification, and do not exclude the possibility of adding one or more other features or constituent elements in advance unless specifically defined.

[0033] As used in this specification and the appended claims, singular expressions include plural expressions unless the context clearly specifies the singular. Also, plural expressions include singular expressions unless the context clearly specifies the plural.

[0034] In addition, the numerical range used in this specification includes the lower limit value and the upper limit value and all values ​​in the range, the increments logically derived from the form and amplitude of the defined range, all values ​​defined therein, and all possible combinations of the upper and lower limits of the numerical range defined in different forms. Unless otherwise specifically defined in the specification of the present invention, values ​​outside the numerical range that may appear due to experimental errors or rounding of numerical values ​​are also included in the defined numerical range.

[0035] The terms "about" and the like of degree used in this specification and the appended claims are used in the sense of encompassing tolerances when there are tolerances.

[0036] Humidity indicator cards are mainly packaged together with humidity-sensitive semiconductor chips, printed circuit boards (PCBs), precision electronic devices, etc., so that the stability of the product to humidity can be easily determined when it is opened. However, conventional humidity indicator cards have a thickness of about 10 mm. 16 Up to 10 18 The surface resistance is very high at Ω / sq. Due to the high surface resistance, when the insulating humidity indicator card contacts the integrated circuit device packaged together, static electricity may be generated due to friction, thereby causing electrostatic discharge (ESD). Due to static electricity, dust or foreign matter in the atmosphere is adsorbed on the integrated circuit device and contaminates it, and electrostatic discharge may cause defects in the integrated circuit device or cause serious safety problems such as fire and explosion.

[0037] In this regard, the applicant has conducted in-depth research and developed a humidity indicator card that includes an antistatic composition containing conductive carbon black to prevent electrostatic discharge between the humidity indicator card and the integrated circuit device, thereby developing a humidity indicator card that can ensure the safety of the device.

[0038] Hereinafter, the present invention will be described with reference to the accompanying drawings.

[0039] The humidity indicator card with an antistatic function according to the present invention comprises blotting paper, antistatic layers located at the upper and lower parts of the blotting paper, and a humidity indicating part located on one side of the antistatic layer, wherein the antistatic layer comprises an antistatic composition containing conductive carbon black, and contains 1 to 30 parts by weight of the conductive carbon black based on 100 parts by weight of the antistatic composition.

[0040] Figure 1 is a diagram showing a humidity indicator card 100 according to an embodiment. Figure 1 As shown in FIG. 1 , the antistatic layer 20 is located at the upper and lower parts of the blotting paper 10 , and a plurality of humidity indicators 30 are located on one side of the antistatic layer, whereby the humidity indicators 30 change color with relative humidity, so that humidity changes can be confirmed with naked eyes.

[0041] The humidity indicator card 100 is provided with the antistatic layer 20 including the antistatic composition, thereby providing excellent antistatic performance as the surface resistance of the humidity indicator card 100 is reduced.

[0042] In one embodiment, based on 100 parts by weight of the antistatic composition, 1 to 30 parts by weight of conductive carbon black may be contained, preferably 3 to 25 parts by weight of conductive carbon black may be contained, more preferably 5 to 20 parts by weight of conductive carbon black may be contained, and most preferably 10 to 20 parts by weight of conductive carbon black may be contained. By containing the conductive carbon black with high conductivity in the above-mentioned parts by weight, the mechanical physical properties of the antistatic layer 20 may be improved. In addition, a humidity indicator card 100 having excellent antistatic performance and economical advantages may be provided.

[0043] The conductive carbon black has excellent electrical conductivity and may have physical properties very different from those of conventionally used general carbon black. As an example, the conductive carbon black may have a specific surface area of ​​50 to 100 m 2 / g, or 60 to 90m 2 / g, and preferably, may be 70 to 80 m 2 As the antistatic composition includes the conductive carbon black having a specific surface area within the above range, the antistatic performance of the conductive carbon black may not be reduced by moisture due to excellent mechanical physical properties, thereby improving durability, and the conductive carbon black is easily mixed with a solvent and a binder of the antistatic composition described later, thereby making the conductive carbon black uniformly dispersed across the entire antistatic layer 20.

[0044] In addition, the oil absorption number (OAN) of the conductive carbon black may be 100 to 300 ml / 100 g, preferably 150 to 250 ml / 100 g, and more preferably 180 to 220 ml / 100 g. As the conductive carbon black having excellent crystallinity and developed structure has the oil absorption number in the above range, high conductivity may be exhibited, and thus the antistatic composition including the conductive carbon black may significantly reduce the surface resistance of the humidity indicator card 100, which is advantageous.

[0045] The conductive carbon black may contain less than 300 ppm of sulfur, preferably less than 200 ppm, most preferably less than 100 ppm, and non-limitingly, more than 0.01 ppm of sulfur. The conductive carbon black contains low concentrations of impurities such as sulfur and metals, thereby improving the conductivity of the conductive carbon black, and significantly reducing the risk of reducing the humidity indication performance due to the impurities, so that the humidity indicator card can maintain high sensitivity.

[0046] In one embodiment, the surface resistance of the humidity indicator card 100 may be 10 3 Up to 10 7 Ω / sq, preferably, can be 10 4 Up to 10 7 Ω / sq, and more preferably, may be 105 Up to 10 7 Ω / sq. As described above, the humidity indicator card 100 of the present invention has the antistatic layer 20 including the conductive carbon black on the upper and lower parts of the blotting paper 10, and thus can prevent static electricity due to the extremely low surface resistance. When electronic devices such as semiconductors and printed circuit boards, electrostatically sensitive products such as automobile parts, communication equipment, optical equipment, sensors, etc. are packaged together with the humidity indicator card 100 of the present invention, problems such as product failure and explosion caused by static electricity can be prevented.

[0047] In one embodiment, the antistatic composition may further include a binder and a solvent. The binder may include a rosin-based resin, specifically, the rosin-based resin may include a rosin-modified phenolic resin, a rosin ester, a rosin-modified maleic acid resin or a combination thereof, and more specifically, the binder may include a rosin-modified phenolic resin.

[0048] Since the porous blotting paper 10 is composed of a porous structure to have concavities and convexities on the surface so as to easily absorb moisture, the close contact between the blotting paper 10 and the antistatic layer 20 may be reduced. Therefore, the antistatic composition further includes a binder, and thus the close contact between the blotting paper 10 including the concavities and convexities and the antistatic layer 20 may be improved, so that the durability of the humidity indicator card 100 may be improved. When the binder is added at a weight ratio exceeding the range, the viscosity of the antistatic composition increases, and thus it may be difficult to uniformly apply the antistatic composition on the blotting paper 10. Specifically, the surface roughness of the blotting paper may be 20 μm or less, 10 μm or less, or 5 μm or less, and may be 0.1 μm or more without limitation.

[0049] In one embodiment, the solvent may include vegetable oil, and illustratively, the vegetable oil may include one or more selected from the group consisting of linseed oil, soybean oil, sunflower oil, and castor oil, preferably, linseed oil and soybean oil may be included, but the present invention is not limited thereto, and other known vegetable oils may be used. As the antistatic composition further includes a solvent including vegetable oil and a binder including a rosin-based resin, the conductive carbon black is uniformly dispersed in the antistatic composition, thereby improving workability.

[0050] As a more specific example, based on 1 part by weight of conductive carbon black, the antistatic composition may include 0.1 to 10 parts by weight or 0.3 to 8 parts by weight of a binder, and preferably, may include 0.5 to 7 parts by weight. In addition, based on 1 part by weight of conductive carbon black, the antistatic composition may include 1 to 20 parts by weight or 1 to 17 parts by weight of a solvent, and preferably, may include 1 to 13 parts by weight. As the antistatic composition includes the solvent and the binder in the parts by weight, the workability is improved, thereby forming an antistatic layer 20 having a uniform thickness on the surface of the blotting paper 10.

[0051] In one embodiment, the antistatic composition may further include a polypyrrole-based polymer having electrical conductivity. Although it is not necessarily limited to this explanation, in the case where a polypyrrole-based polymer that is very stable in an oxidized state and has excellent stability and high electrical conductivity is also included, excellent electrical conductivity can be maintained even when exposed to a humid environment, thereby enhancing the antistatic effect of the humidity indicator card, which is advantageous.

[0052] In one embodiment, the blotting paper 10 is a kind of paper specially made to absorb moisture well, and its basis weight can be 300 to 400 g / m 2 305 to 380 g / m 2 , 310 to 360 g / m 2 and 315 to 340 g / m 2 , and substantially, may be 315 to 320 g / m 2 In addition, the thickness of the blotting paper may be 400 to 500 μm, 410 to 490 μm, 420 to 480 μm, and 430 to 470 μm, and substantially, 440 to 460 μm. The blotting paper 10 after the quantitative comparison of the thickness of the paper per unit area may include a plurality of voids, and thus may have excellent hygroscopicity.

[0053] More specifically, the hygroscopicity of the blotting paper 10 may be 40 to 200 seconds, 60 to 180 seconds, 80 to 160 seconds, and substantially, 100 to 150 seconds. The hygroscopicity is used to measure the time required for the blotting paper 10 to be completely wetted with water. With the hygroscopicity in the above range, the relative humidity can be accurately sensed with high durability and for a long time.

[0054] In one embodiment, the humidity indicating portion 30 may not include an antistatic composition. In the case where an antistatic composition containing conductive carbon black is coated on the humidity indicating portion 30, since the humidity indicating portion 30 is colored, it may be difficult to discern a color change according to a humidity change with the naked eye. Therefore, the antistatic composition is coated in an area other than the humidity indicating portion 30, whereby a color change according to a humidity change can be clearly observed while the humidity indicator card 100 provides an antistatic effect.

[0055] Furthermore, with the use of the blotting paper 10 having the aforementioned basis weight and hygroscopic properties, the antistatic composition is prevented from contaminating the humidity indicating portion 30 due to moisture, thereby improving the durability and life of the humidity indicator card 100.

[0056] In one embodiment, the humidity indicator card 100 may include a plurality of humidity indicator portions 30. Different critical humidity values ​​are set for the individual humidity indicator portions 30a, so that as the relative humidity increases, the colors of the individual humidity indicator portions 30a may change sequentially. In a non-limiting and specific example, when the relative humidity is above 10%, the color of the first humidity indicator portion 30a may change, when the relative humidity is above 30%, the color of the second humidity indicator portion 30b may change, and when the relative humidity rises to above 50%, the color of the third humidity indicator portion 30c may change, so that the humidity change may be judged more sensitively.

[0057] In one embodiment, the humidity indicator 30 includes an indicator liquid whose color changes with pH, ​​so that the color of the humidity indicator 30 can change with relative humidity. Specifically, the color of the humidity indicator 30 below the critical humidity value is different from the color of the humidity indicator 30 above the critical humidity value, so that the humidity change can be easily observed with the naked eye.

[0058] As a non-limiting example, the number of the humidity indicating parts 30 may be 1 to 20, specifically, 2 to 15, and more specifically, 3 to 10, but the present invention is not limited thereto.

[0059] The present invention includes a method for manufacturing a humidity indicator card 100 with an added anti-static function.

[0060] When describing the method for manufacturing the humidity indicator card 100 of the present invention, the materials, structures, shapes or sizes of the blotting paper 10, the antistatic composition, the antistatic layer 20, the humidity indicating portion 30 and the humidity indicator are the same as or similar to those of the aforementioned humidity indicator card 100. Therefore, the method for manufacturing the humidity indicator card of the present invention includes all the contents described in the aforementioned humidity indicator card 100.

[0061] The manufacturing method of the humidity indicator card 100 with an antistatic function according to the present invention is as follows: Figure 2As shown in the sequence diagram, the method comprises: (S10) coating an antistatic composition containing conductive carbon black on the upper and lower parts of a blotting paper 10 to form an antistatic layer 20; (S20) forming a humidity indicator portion 30 on one side of the antistatic layer 20 to manufacture a humidity indicator card 100; and (S30) drying the humidity indicator card 100, wherein the conductive carbon black is contained in an amount of 1 to 30 parts by weight based on 100 parts by weight of the antistatic composition.

[0062] In one embodiment, in step (S10), the antistatic composition may be applied to the upper and lower portions of the blotting paper 10 by any one of screen printing, gravure printing, offset printing, planographic printing, or flexographic printing to form the antistatic layer 20. When forming the antistatic layer 20, the area to be coated with the antistatic composition is set in advance by a program, so that the antistatic composition may be coated in areas other than the humidity indicating portion 30.

[0063] Figure 3 2 is a diagram showing an blotting paper 10 in which an antistatic composition is applied to the upper and lower portions of the blotting paper 10 to form an antistatic layer 20. Figure 3 As shown in , a blotting paper 10 formed with a plurality of humidity indicator cards 100 can be manufactured by printing an antistatic composition on the upper and lower portions of the blotting paper 10. A single humidity indicator card 100 can be manufactured by cutting the blotting paper 10 printed with the antistatic composition.

[0064] Figures 4 to 6 is a diagram showing the blotting paper 10 cut by the (S15) step. Specifically, Figure 4 is a diagram showing the upper portion of the blotting paper 10, and Figure 5 and Figure 6 1 is a diagram showing the lower part of the blotting paper 10. When the antistatic composition is applied, it is applied to the area other than the humidity indicator 30, so that the color change of the humidity indicator 30 according to the change of relative humidity can be clearly recognized as the humidity indicator 30 does not include conductive carbon black. Figure 5 As shown, the lower portion of the blotting paper 10 may print the antistatic composition on an area other than the humidity indicating portion 30, and as shown in FIG. Figure 6 As shown, it is also possible to print the antistatic composition in the area of ​​the humidity indicating portion 30 at the lower portion of the blotting paper 10 to form the antistatic layer 30 .

[0065] In step ( S20 ), a humidity indicator may be impregnated into the upper region of the blotting paper 10 not coated with the antistatic composition to form the humidity indicator part 30 .

[0066] In a preferred example, the humidity indicator may include a main indicator liquid whose color changes according to pH, an auxiliary indicator liquid whose pH is adjusted so that the color changes according to relative humidity, and an indicator liquid containing an additive that changes the pH of the humidity indicator liquid according to relative humidity. The indicator liquid does not contain cobalt and heavy metals, which are potential carcinogens, thereby manufacturing an environmentally friendly humidity indicator card 100, which is advantageous.

[0067] The main indicator liquid may be a known acid-base indicator liquid, and representative examples thereof include thymol blue, resazurin, and the like. The auxiliary indicator liquid may include one selected from the group consisting of sulfuric acid, hydrochloric acid, citric acid, oxalic acid, acetic acid, sodium hydroxide, and potassium hydroxide, and the additive may include a deliquescent substance. More specifically, the humidity indicator 30 may be manufactured with reference to Korean registered patent No. 10-1605193 or No. 10-1344949 of the present applicant.

[0068] Among the plurality of humidity indicating parts 30 included in the humidity indicator card 100, by adjusting the content of the additive included in the humidity indicator, a critical humidity value different for each humidity indicating part 30a can be set. As described above, as the relative humidity increases, the colors of the individual humidity indicating parts 30 are sequentially changed, respectively, thereby making it possible to measure the relative humidity with high accuracy.

[0069] In another example, the humidity indicator may also include one selected from the group consisting of cobalt chloride (CoCl 2 ), cobalt bromide (CoBr 2 ), and copper (Cu), but the present invention is not limited to the specific substance of the humidity indicator.

[0070] In step (S30), the humidity indicator card 100 in which the humidity indicator is impregnated into the humidity indicating part 30 may be dried to manufacture the humidity indicator card 100 including the antistatic composition. The drying temperature may be 40 to 100° C., 45 to 90° C., 50 to 80° C., and 55 to 75° C., and may be substantially 55 to 70° C.

[0071] As the antistatic composition includes the conductive carbon black in the above-mentioned parts by weight, even if heat treatment is performed at a high temperature, antistatic performance may be maintained without being reduced.

[0072] In step (S40), the humidity indicator card 100 that has been dried can be sealed and packaged. When sealed, it can be sealed and packaged in a moisture-proof bag or a tin can together with a desiccant according to the International Semiconductor Association standard (IPC / JEDEC J-STD-033).

[0073] The completed humidity indicator card 100 can be packaged and distributed together with moisture-sensitive products, such as semiconductors, printed circuit boards, surface mount devices (SMDs), displays, communication equipment, optical equipment, precision analysis sensors, automotive parts, electronic parts, missile ammunition, gunpowder, and propellant charges.

[0074] The moisture-sensitive product is sealed together with the humidity indicator card 100 of the present invention, thereby significantly reducing the risk of device misoperation, damage, fire and explosion caused by electrostatic discharge to improve safety.

[0075] Hereinafter, the present invention will be described in more detail by way of examples.

[0076] (Example 1)

[0077] The antistatic composition was applied to a volume of 320 g / m by screen printing. 2 , the thickness is 450 μm and the hygroscopicity is 105 seconds of the upper and lower parts of the blotting paper to form an antistatic layer. The antistatic composition includes conductive carbon black (DC3501-P2, OCI), rosin-modified phenolic resin as a binder, and linseed oil and soybean oil as a solvent, and 5% by weight of conductive carbon black, 30% by weight of the binder and 65% by weight of the solvent are added to make the antistatic composition. When forming the antistatic layer, the antistatic composition is printed in the area outside the humidity indicating portion of the upper and lower parts of the blotting paper.

[0078] A blotting paper printed with an antistatic layer was cut, and a humidity indicator was impregnated on one side of the antistatic layer to form a humidity indicator. Specifically, the humidity indicator was manufactured by impregnating a main indicator containing methyl blue, a pH regulator containing acetic acid, a moisture absorption regulator, a stabilizer containing polysorbate, an ultraviolet blocker containing Tinogard N of BASF, and a defoamer containing Defom W-0506 of Elementis in an ethanol solvent. Subsequently, the humidity indicator card formed with the humidity indicator was dried in an oven at 60° C. for 1 hour to manufacture the humidity indicator card.

[0079] (Example 2)

[0080] A humidity indicator card was manufactured by the same method as Example 1, except that an antistatic composition including 10 wt % of conductive carbon black, 30 wt % of a binder, and 55 wt % of a solvent was used.

[0081] (Example 3)

[0082] A humidity indicator card was manufactured by the same method as Example 1, except that an antistatic composition including 15 wt % of conductive carbon black, 30 wt % of a binder, and 55 wt % of a solvent was used.

[0083] (Example 4)

[0084] A humidity indicator card was manufactured by the same method as Example 1, except that an antistatic composition including 20 wt % of conductive carbon black, 30 wt % of a binder, and 50 wt % of a solvent was used.

[0085] (Example 5)

[0086] A humidity indicator card was manufactured by the same method as Example 1, except that an antistatic composition including 25 wt % of conductive carbon black, 30 wt % of a binder, and 45 wt % of a solvent was used.

[0087] (Example 6)

[0088] A humidity indicator card was manufactured by the same method as Example 1, except that an antistatic composition including 30 wt % of conductive carbon black, 30 wt % of a binder, and 40 wt % of a solvent was used.

[0089] (Comparative Example 1)

[0090] A humidity indicator card was manufactured by the same method as Example 1, except that the antistatic composition included general carbon black (EG880, OCI).

[0091] (Comparative Example 2)

[0092] A humidity indicator card was manufactured by the same method as Example 3, except that the antistatic composition included general carbon black (EG880, OCI).

[0093] (Comparative Example 3)

[0094] A humidity indicator card was manufactured by the same method as Example 1, except that the antistatic composition included 40 wt % of conductive carbon black, 20 wt % of a binder, and 40 wt % of a solvent.

[0095] (Comparative Example 4)

[0096] A humidity indicator card was manufactured by the same method as in Example 1, except that general paper having a moisture absorption of 250 seconds was used instead of the blotting paper.

[0097] The contents of the components included in the antistatic compositions of Examples 1 to 6 and Comparative Examples 1 to 4 are summarized in Table 1 below.

[0098] [Table 1]

[0099]

[0100]

[0101] (Experimental Example 1) Evaluation of Physical Properties of Carbon Black

[0102] The physical properties of the conductive carbon black of Example 1 and the general carbon black of Comparative Example 1 are compared and shown in the following Table 2. Specifically, the BET specific surface area was measured according to the specification according to ASTM D4820, the oil absorption number (OAN) was measured according to the specification according to ASTM D2414-00, and the d-spacing was measured using an X-ray diffraction method.

[0103] [Table 2]

[0104]

[0105] As shown in Table 2, it can be confirmed that the conductive carbon black used in Example 1 has physical properties that are very different from those of general carbon black.

[0106] Specifically, it was measured that the specific surface area of ​​the conductive carbon black was small and the oil absorption was significantly high compared to the general carbon black. The conductive carbon black having the specific surface area can be uniformly dispersed in the antistatic composition, and at the same time, the high oil absorption indicates that the conductive carbon black has a developed structure, so it can be known that the conductive performance is excellent. On the contrary, compared to the conductive carbon black, the specific surface area of ​​the general carbon black is large, so there is a disadvantage of high difficulty in dispersion, and it is known that the oil absorption is significantly low and the conductivity is low.

[0107] In the case of d-spacing, which means the distance between (002) planes of carbon black, the d-spacing of the conductive carbon black is smaller than that of the general carbon black, and thus it can be known that the crystallinity of the conductive carbon black is improved. In addition, when the concentrations of sulfur and metal included in the carbon black as impurities are compared, it is measured that the concentration of impurities included in the conductive carbon black is significantly reduced compared to the general carbon black.

[0108] Therefore, as the conductive carbon black having physical properties significantly different from those of general carbon black is excellent in crystallinity and has a developed structure, the conductivity is significantly improved, thereby contributing to reducing the surface resistance of the humidity indicator card. At the same time, as the dispersibility of the conductive carbon black having a specific surface area in an appropriate range is improved to be uniformly dispersed on the antistatic composition, a uniform antistatic effect can be achieved across the entire antistatic layer. In addition, by using conductive carbon black having a significantly reduced content of impurities such as sulfur and metals, the conductivity is improved, and by significantly reducing the risk of reduced humidity indication performance of the humidity indicating portion due to impurities, the humidity indicator card including the antistatic composition can measure relative humidity with high sensitivity.

[0109] (Experimental Example 2) Evaluation of antistatic performance

[0110] The surface resistance of the humidity indicator cards manufactured by the methods of Examples 1 to 6 and Comparative Examples 1 to 4 was measured using SIMCO ST-4. The surface resistance measurement results are shown in Table 3 below.

[0111] [Table 3]

[0112] Surface resistance (Ω / sq) Example 1 <![CDATA[10 6.8 ]]> Example 2 <![CDATA[10 6.1 ]]> Example 3 <![CDATA[10 5.6 ]]> Example 4 <![CDATA[10 5.9 ]]> Example 5 <![CDATA[10 7.3 ]]> Example 6 <![CDATA[10 7.5 ]]> Comparative Example 1 <![CDATA[10 14.5 ]]> Comparative Example 2 <![CDATA[10 14.1 ]]> Comparative Example 3 <![CDATA[10 14.8 ]]> Comparative Example 4 <![CDATA[10 15.3 ]]>

[0113] Compared with Comparative Examples 1 to 3, the surface resistance of the humidity indicator cards of Examples 1 to 6 was significantly reduced, and thus it was confirmed that the antistatic effect was excellent. In particular, the humidity indicator cards of Examples 1 to 4 including 5 to 20 parts by weight of conductive carbon black showed 10 7 The surface resistance is less than Ω / sq, so it is known that it has excellent antistatic effect.

[0114] In contrast, the surface resistance of the humidity indicator cards of Comparative Examples 1 to 3 is / sq or more, it showed a significantly higher surface resistance than Examples 1 to 6, and therefore it was confirmed that no antistatic effect was provided.

[0115] Specifically, the humidity indicator cards of Comparative Examples 1 and 2 use an antistatic composition including general carbon black instead of conductive carbon black. General carbon black has lower conductivity than conductive carbon black, includes impurities, and as conductivity decreases when mixed with a binder and a solvent, a high surface resistance is measured.

[0116] In the case of Comparative Example 3, an excessive amount of conductive carbon black is included in the antistatic composition, so as the content of the solvent and the binder decreases, the viscosity of the antistatic composition increases. Therefore, the antistatic composition is not uniformly dispersed on the surface of the blotting paper, so it can be seen that the antistatic effect cannot be achieved.

[0117] Comparative Example 4 is a humidity indicator card manufactured by using general paper with a humidity absorption of 250 seconds instead of blotting paper with a humidity absorption of 105 seconds. Compared with the humidity indicator card of Example 1 using blotting paper, it shows a very high surface resistance, and thus it is confirmed that there is no antistatic effect. In addition, even if the humidity rises, the color of the humidity indicator portion does not change clearly, so it is difficult to distinguish the humidity change with the naked eye. In contrast, when the humidity indicator card is manufactured using general paper instead of blotting paper, the antistatic effect cannot be provided due to the high surface resistance, and there is a problem that the humidity change cannot be accurately displayed because it cannot quickly absorb moisture in the atmosphere.

[0118] In summary, although the present invention is described through embodiments and drawings defined together with specific matters, they are only provided to help a more comprehensive understanding of the present invention. The present invention is not limited to the embodiments, and ordinary technicians in the technical field to which the present invention belongs can make various modifications and variations from such descriptions.

[0119] Therefore, the concept of the present invention should not be limited to the illustrated embodiments, and the appended claims and modifications equivalent to or equivalent to the claims should all fall within the scope of the concept of the present invention.

Claims

1. A humidity indicator card with an anti-static function, the humidity indicator card comprising: blotting paper; Antistatic layers, the antistatic layers are located on the upper and lower parts of the blotting paper; as well as A humidity indicator, wherein the humidity indicator is located on one side of the antistatic layer, The antistatic layer comprises an antistatic composition containing conductive carbon black, Based on 100 parts by weight of the antistatic composition, 1 to 30 parts by weight of the conductive carbon black is contained.

2. The humidity indicator card according to claim 1, wherein the antistatic composition further comprises a binder and a solvent.

3. The humidity indicator card of claim 2, wherein the adhesive comprises a rosin-based resin.

4. The humidity indicator card of claim 2, wherein the solvent comprises vegetable oil.

5. The humidity indicator card according to claim 1, wherein the conductive carbon black has a specific surface area of ​​50 to 100 m 2 / g.

6. The humidity indicator card according to claim 1, wherein the oil absorption of the conductive carbon black is 100 to 300 ml / 100 g.

7. The humidity indicator card of claim 1, wherein the conductive carbon black contains less than 300 ppm of sulfur.

8. The humidity indicator card according to claim 1, wherein the hygroscopicity of the blotting paper is 40 to 200 seconds.

9. The humidity indicator card according to claim 1, wherein the thickness of the blotting paper is 400 to 500 μm.

10. The humidity indicator card according to claim 1, wherein the surface resistance of the humidity indicator card is 10 3 Up to 10 7 Ω / sq.

11. The humidity indicator card of claim 1, wherein the antistatic composition further comprises a polypyrrole-based polymer.

12. The humidity indicator card of claim 1, wherein the humidity indicating portion does not include an antistatic composition.

13. A method for manufacturing a humidity indicator card with an anti-static function, comprising the following steps: (S10) applying an antistatic composition containing conductive carbon black to the upper and lower parts of the blotting paper to form an antistatic layer; (S20) forming a humidity indicator portion on one side of the antistatic layer to manufacture a humidity indicator card; and (S30) drying the humidity indicator card, Based on 100 parts by weight of the antistatic composition, 1 to 30 parts by weight of the conductive carbon black is contained.

14. The method for manufacturing a humidity indicator card according to claim 13, wherein in the step (S30), the drying temperature is 40 to 100°C.

15. The method for manufacturing a humidity indicator card according to claim 13, wherein in the step (S10), the antistatic composition is applied to a region other than a humidity indicator region.

16. The method for manufacturing a humidity indicator card according to claim 13, further comprising the following steps after step (S10): (S15) Cutting the blotting paper including the antistatic layer.

17. The method for manufacturing a humidity indicator card according to claim 13, further comprising the following steps after step (S30): (S40) Sealing the dried humidity indicator card.

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