JP2005187992A - Paper for pseudo-adhesion, pseudo-adhesive paper and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paper for former-paste pseudo-adhesive use having excellent masking power and recordability in electrophotographic recording apparatus. <P>SOLUTION: The paper for former-paste pseudo-adhesive use has an arithmetic surface roughness Ra (JIS B 0601) of 3-15μm on the pseudo-adhesive layer surface determined by a contact-type surface roughness tester in conformity to JIS B 0651. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pseudo-adhesive paper having a function of temporarily adhering but easily peeling when necessary, and a method for manufacturing the same. In particular, after providing a pseudo-adhesive layer on the base paper, to the pseudo-adhesive paper or pseudo-adhesive layer of the pre-glue method used by printing / printing characters / graphics etc. on the pseudo-adhesive layer On the other hand, the present invention relates to pseudo-adhesive paper on which characters / graphics are printed / printed.

  Pseudo-adhesive paper is, for example, folded with the pseudo-adhesive layer surface on which various information such as confidential information is printed / printed as the inner surface, and the superimposed surface is pseudo-adhered to conceal the information and sent by mail. It is often used in postcard systems and the like that peel off and read concealment information. In such applications, high concealment is required so that confidential information cannot be seen through and read by a third party. Therefore, improvement of opacity in order to improve concealment has been a challenge in the industry.

  On the other hand, the printing / printing of the pseudo-adhesive paper is, for example, the frame printing or pattern printing (also referred to as form printing) other than variable information that differs for each postcard represented by confidential information, personal information, etc., taking the postcard system as an example. ) Is often performed on an offset printing machine capable of high-speed, high-contrast printing and printing. For recording variable information such as confidential information and personal information, an electrophotographic system typified by a laser printer or NIP printer is used. This is often performed by a recording apparatus. Therefore, in the pseudo-adhesive paper, these form printability and electrophotographic recordability are also important.

By the way, an electrophotographic recording apparatus employs a configuration in which fine toner is thermally melted by a heat roll, a flash, or the like, and transferred to a sheet for printing and printing. Accordingly, the paper is discharged from the recording apparatus while being heated to some extent.
JP 2003-105287 A JP2003-072265 JP2002-023643

  With the recent increase in the speed of electrophotographic recording apparatuses, adverse effects of being discharged in a heated state in printing / printing of pseudo-adhesive paper are beginning to occur.

  That is, when printing variable information on pseudo-adhesive paper with an NIP printer, the pseudo-adhesive paper ejected after printing may be temporarily stored in a folded or rolled-up state. Increasing the speed of the apparatus has led to many situations in which the toner is not sufficiently fixed due to heat accumulation, for example, without being sufficiently lowered in temperature.

  In addition, in the pre-adhesive type pseudo-adhesive paper, the pseudo-adhesion may be sent continuously to the pseudo-adhesion process immediately after printing / printing so that the concealment information is not exposed as much as possible. In many cases, the toner is sent to the pseudo-adhesion process without being lowered, and the toner is pseudo-adhered without being completely fixed on the paper.

  As described above, when pseudo-adhesion or the like is performed with the toner fixing being incomplete, the printing / printing portion is blocked from the facing surface, and the information is transferred to the facing surface during re-peeling. Cannot be read.

  Therefore, the main problem of the present invention is to improve the opacity and prevent troubles associated with recording in the electrophotographic system in the pre-glue type pseudo-adhesive paper.

The present invention that has solved the above-described problems and the effects thereof are as follows.
<Invention of Claim 1>
At least one side of the base paper has a pseudo-adhesive layer that can be peeled off when given conditions are given without being bonded under normal conditions, and characters / graphics are printed / printed on the surface of the pseudo-adhesive layer Is a so-called pre-glue type pseudo-adhesive paper,
The pseudo-adhesive layer surface has an arithmetic surface roughness Ra defined by JIS B 0601 measured by a stylus type surface roughness measuring instrument defined by JIS B 0651 of 3-15 μm. Paper.

<Invention of Claim 2>
The pseudoadhesive paper according to claim 1, which has been subjected to an unevenness treatment.

<Invention of Claim 3>
3. A pseudo-adhesive paper, wherein information is recorded on a surface of the pseudo-adhesive layer of the pseudo-adhesive paper according to claim 1 by an electrophotographic recording apparatus.

<Invention of Claim 4>
The pseudo adhesive paper according to claim 3, wherein the pseudo adhesive layers are pseudo bonded.

<Invention of Claim 5>
At least one side of the base paper has a pseudo-adhesive layer that can be peeled off when given conditions are given without being bonded under normal conditions, and characters / graphics are printed / printed on the surface of the pseudo-adhesive layer A so-called pre-glue type pseudo-adhesive paper manufacturing method,
It is specified in JIS B 0601 after applying a roughening treatment to the base paper, applying a pseudo-adhesive to the roughening treatment surface, and measuring with a stylus type surface roughness measuring instrument specified in JIS B 0651. A method for producing pseudo-adhesive paper, comprising forming a pseudo-adhesive layer surface having an arithmetic surface roughness Ra of 3 to 15 μm.

<Invention of Claim 6>
At least one side of the base paper has a pseudo-adhesive layer that can be peeled off when given conditions are given without being bonded under normal conditions, and characters / graphics are printed / printed on the surface of the pseudo-adhesive layer A so-called pre-glue type pseudo-adhesive paper manufacturing method,
After applying the pseudo-adhesive to the base paper, the coated surface is subjected to a roughening treatment, and the arithmetic surface defined by JIS B 0601 is measured with a stylus type surface roughness measuring instrument defined by JIS B 0651. A method for producing pseudo-adhesive paper, comprising forming a pseudo-adhesive layer surface having a roughness Ra of 3 to 15 µm.

<Invention of Claim 7>
The information is recorded on the pseudo-adhesive layer surface of the pseudo-adhesive paper according to claim 5 or 6 by an electrophotographic recording apparatus, and then folded so that the information recording surface is on the inner surface side, and a predetermined pressure is applied to simulate the information. A method for producing pseudo-adhesive paper, characterized in that adhesive layers are pseudo-adhered to each other.

  When the arithmetic surface roughness Ra specified in JIS B 0601 measured by a stylus type surface roughness measuring instrument specified in JIS B 0651 on the surface of the pseudo-adhesive layer is 3 to 15 μm, the toner fixing property is affected. Without giving, the heat dissipation on the surface of the pseudo-adhesive layer becomes good, the toner is fixed quickly, and the situation where the pseudo-adhesion occurs while the toner is not completely fixed does not occur. And if uneven | corrugated processing is given after base paper or pseudo-adhesive layer formation, it is easy to make arithmetic average roughness Ra 3-15 micrometers, and also a space is made between the pseudo-adhesive layer surfaces after pseudo-adhesion. The heat dissipation after adhesion is enhanced, and light scattering occurs on the uneven surface, so that the concealment information is difficult to visually recognize from the outside and has excellent concealability.

  In addition, arithmetic surface roughness Ra in this invention means the value measured by setting a cutoff value as the standard value prescribed | regulated to JISB0601, and evaluation length 5mm.

Next, embodiments of the present invention will be described in detail below.
The pseudo-adhesive paper of the present embodiment is a pre-adhesive pseudo-adhesive paper. In other words, at least one side of the base paper has a pseudo-adhesive layer that can be peeled off when a predetermined condition is applied without being bonded in a normal state, and characters / graphics are printed on the surface of the pseudo-adhesive layer.・ Printed and used.

  Characteristically, the pseudo adhesive layer surface of the pseudo adhesive sheet of the present invention has an arithmetic surface roughness Ra of 3 to 15 μm as defined in JIS B 0601 (measurement of surface roughness of industrial products). When the arithmetic surface roughness is less than 3 μm, heat dissipation is poor and toner fixing is likely to be incomplete, and internal heat does not escape when pseudo-adhering, and toner is easily transferred to the surface facing the printing surface. . On the other hand, when the thickness exceeds 15 μm, it becomes difficult to ensure the pseudo-adhesiveness (performance to adhere to a re-peelable state).

  In the present invention, the arithmetic surface roughness is measured at least three times in the longitudinal direction and the transverse direction of the paper, and the average value is obtained.

  In order to obtain a pseudo-adhesive paper with the above arithmetic surface roughness, it is easy to manufacture by providing a pseudo-adhesive on a base paper that has been subjected to a roughening process represented by embossing on the base paper in advance. Can do. Moreover, you may give an uneven | corrugated process after pseudo-adhesive layer formation.

  The roughening process can be performed by a conventionally known technique. For example, if the base paper is roughened, it can be pressed by pressing with a felt or embossing roll having a rough surface in a wet paper state in a press part of a paper machine. After drying, it can be pressed with an embossing roll to make it uneven. If the roughening treatment is performed after the pseudo adhesive layer is formed, the roughening treatment can be performed by pressing the pseudo adhesive layer surface with an embossing roll or the like after the pseudo adhesive layer is formed.

  The concave / convex pattern is not particularly limited. For example, as shown in FIG. 1, the concave / convex pattern has a square shape (a: 0.2 to 0.5 mm) in a plan view, and the top is flat (b: 0.1 to 0) in a cross sectional view. .3 mm) embossed patterns (d: 0.2 to 0.8 mm) are preferably arranged in a grid pattern at equal intervals (c: 0.1 to 0.5 mm).

  In the present invention, the type of the base paper, the raw material, etc. are not particularly limited. For example, high-quality paper mainly composed of virgin pulp, various mechanical pulps such as PGW, GP, and TMP, and paper blended with waste paper pulp such as newspapers, leaflets, and magazines may be used. Preferably, it is a high quality paper made from a chemical pulp such as LBKP or NBKP. In particular, when it is desired to differentiate from other products, it may be used after being dyed to the same degree as colored fine paper. From the viewpoint of environmental protection, it is preferable to use TCF pulp or ECF pulp that does not use chlorine.

  In order to improve the concealability, the base paper preferably contains 5 to 40% by weight of filler as necessary. Specific examples of fillers include clay, calcite-based precipitated calcium carbonate forming primary or secondary aggregates, aragonite-based precipitated calcium carbonate forming secondary aggregates, calcium carbonate, silica, synthesis For fine particle silica, amino surface modified silica, wax surface treated silica, spherical silica, normal calcium, metal oxide such as zinc, magnesium, aluminum or titanium, hydroxide, carbonate, silicate, coated paper, etc. Examples thereof include plastic pigments such as polyethylene resin, urea resin particles, polystyrene resin particles, styrene / acrylic copolymer particles, urea formalin resin particles, or a mixture thereof. The filler may take the form of fine hollow particles, porous particles and the like.

  The base paper can also contain a paper strength enhancer and the like. When a paper strength enhancer is included, paper delamination is unlikely to occur during re-peeling. As the paper strength enhancer, water-soluble resins, aqueous emulsion resins, and the like can be used, for example, polyacrylamide, acrylic copolymer resins, PVA , Vinyl acetate resin, styrene / butadiene latex, acrylic / styrene copolymer, olefin resin and the like.

  In order to include a filler and a paper strength enhancer in the base paper, they may be added to the pulp slurry before paper making.

  The pseudo-adhesive layer is filled with a non-peelable adhesive (hereinafter referred to as “adhesive base”) on both sides or one side of the base paper, and an organic pigment, an inorganic pigment, or the like that has no affinity for the non-peelable adhesive. It can be formed by coating a general pseudo-adhesive with a pseudo-adhesive property by coating with a coating machine or the like. The blending ratio of the non-peeling adhesive and the pigment may be a general blending ratio of a kind of pseudo-adhesive formed by adding a pigment or the like to the non-peeling adhesive. The amount of the pigment is about 5 to 500 parts by weight with respect to 100 parts by weight of the agent. In the present invention, a particularly preferable range is 10 to 300 parts by weight of the filler with respect to 100 parts by weight of the non-peelable adhesive.

  As the adhesive base, it can be arbitrarily selected from those conventionally used for usual adhesive bases such as latex, specifically natural rubber, synthetic rubber, etc. Sulfur-free vulcanized natural rubber latex mixed with methyl methacrylate, natural rubber latex obtained by graft copolymerization of methyl methacrylate with natural rubber, acrylic modified rubber latex, rubber latex and protective colloidal acrylic copolymer A mixture with a polymerized emulsion is preferred in terms of blocking resistance, resistance to deterioration over time, and the like.

  Examples of the organic pigment include plastic pigments used for raw starch, coated paper, urea resin particles, polystyrene resin particles, styrene / acrylic copolymer particles, urea formalin resin particles, and the like. These may be used alone or in combination. Particularly preferred are plastic pigments made of polyethylene resin and styrene / acrylic copolymer particles. Further, the organic pigment may be in the form of fine hollow particles, porous particles or the like.

  Examples of the inorganic pigment include calcite-based precipitated calcium carbonate (Shiraishi Kogyo Co., Ltd .: PC, Callite KT) that forms primary or secondary aggregates, and aragonite-based settleable that forms secondary aggregates. Calcium carbonate (Shiraishi Kogyo Co., Ltd .: Callite SA), heavy calcium carbonate, kaolin, silica, synthetic fine particle silica, amino surface modified silica, wax surface treated silica, spherical silica, normal calcium, zinc, magnesium, aluminum Alternatively, oxides of metal such as titanium, hydroxides, carbonates, silicates, and the like can be given. These may be used alone or in combination.

  In the pseudo-adhesive, other additives such as lubricants, printability improvers, antioxidants, UV absorbers, conductive agents, fluorescent dyes, colored dyes, preservatives, moisturizers, fixing agents for inkjet inks, etc. Can be blended.

Application of the pseudo adhesive to the base paper can be performed by a coating method using a conventionally known coating machine. However, when providing a pseudo-adhesive layer on the base paper that has been subjected to the roughening process, care must be taken not to fill the emboss. Therefore, in this case, the coating amount of the pseudo adhesive layer is appropriately changed depending on the base paper used. Generally, the coating amount is 3 to 15 g / m ² . If the coating amount is less than 3 g / m ^2, it is difficult to obtain a desired adhesive force. If it exceeds 15 g / m ² , the adhesive force becomes too strong to be easily peeled off. Glue sticks to the rolls, which can easily cause operational and quality problems. A coating machine is not specifically limited, For example, it can coat using an air knife coater, a blade coater, a rod metering coater, a curtain coater, and a roll coater.

  You may perform a calendar process after coating. However, it should be noted that the calendar process after the uneven process changes the surface roughness. In addition, when the uneven | corrugated process is performed on the coated surface after applying the pseudo adhesive on the base paper, the calender roll may be provided with unevenness and used as an embossing device. The calendar processing device or the embossing device may be a so-called on-machine type that forms a series with the coating machine, or may be a completely separate off-machine type that is not a series with the coating machine. Moreover, the calendar | calender apparatus which combined the metal roll, the elastic roll, or metal rolls, and an embossing provision apparatus can be used.

  Examples (Examples 1 to 13) of the present invention and comparative examples (Comparative Examples 1 to 8) were tested and evaluated for hiding, heat dissipation, and toner blocking.

<Base paper>
In Examples 1 to 5, raw material pulp blended at the ratio shown in Table 1 below, 3 kg / pulpton of internal sizing agent (AKD), and 2 kg of polyacrylamide water-soluble resin / pulpton as an internal paper strength enhancer Furthermore, the raw material before papermaking containing talc so that the ratio after drying is 5% by weight is made into wet paper, pressed with uneven felt and then processed to make unevenness, and dried on raw paper. A base paper produced by applying a size press solution containing 10% by weight of starch on the front and back surfaces and drying the same was used.

  In Examples 6 to 13, the raw material pulp in which the pulp was blended at the ratio shown in Table 1 below, 3 kg / pulpton of internal sizing agent (AKD), 2 kg of polyacrylamide water-soluble resin / pulpton blended as an internal paper strength enhancer Further, a dry press paper made from a pre-paper-making raw material blended with talc so that the ratio after drying is 5% by weight is coated with a size press solution containing 10% by weight of raw starch on the front and back surfaces, and then dried. A base paper produced by pressing with an embossing roll and making it uneven was used.

  In Comparative Examples 1 to 4, the raw material pulp in which the pulp is blended at the ratio shown in Table 1 below, 3 kg / pulpton of internal sizing agent (AKD), and 2 kg of polyacrylamide water-soluble resin / pulpton as an internal paper strength enhancer Further, a dry base paper made from a raw material before paper making containing talc so that the proportion after drying is 5% by weight, and a size press solution containing 10% by weight raw starch is applied to the front and back surfaces and dried. A base paper was used. The roughening treatment was not performed.

  Comparative Examples 5 to 8 were prepared by mixing 3 kg / pulpton of internal sizing agent (AKD) and 2 kg of polyacrylamide water-soluble resin / pulpton as an internal paper strength enhancer in the raw pulp blended with pulp at the ratio shown in Table 1 below. Further, a dry press paper made from a pre-paper-making raw material blended with talc so that the ratio after drying is 5% by weight is coated with a size press solution containing 10% by weight of raw starch on the front and back surfaces, and then dried. A base paper produced by pressing with an embossing roll and making it uneven was used.

The basis weights of the base papers in each example and each comparative example were all 104.7 g / m ² . In each of the examples and comparative examples, the concavo-convex treatment was carried out using both felt concavo-convex treatment and embossing roll concavo-convex treatment in FIG. 1 with a: 0.75 mm, b: 0.25, d: 0. The uneven pattern was 25 mm. The height c was made different for each example in order to make the surface roughness different. The height c in each example and each comparative example is as shown in Table 1.

<Pseudo adhesive layer>
The pseudo adhesive layers in each of the examples and the comparative examples are all composed of 10 parts of a synthetic rubber latex / water-soluble binder in a dispersion composed of 25 parts by weight of silica and 25 parts by weight of raw starch with respect to 30 parts by weight of natural rubber latex. The pseudo-adhesive containing part by weight was formed by coating on both sides with a flow coater so as to be 8 g / m ² per side after drying.

<Measurement method and evaluation>
The physical property measurement methods, test methods, and evaluation criteria of each Example and each Comparative Example were as follows.

[Surface roughness]
The arithmetic surface roughness defined in JIS B 0601 was measured with a stylus type surface roughness measuring instrument (AY-41: manufactured by Kosaka Laboratory Ltd.) defined in JIS B 0651 on the pseudo adhesive layer surface. .

[Whiteness]
The whiteness of the pseudo adhesive layer surface was measured according to JIS P 8123 (Paper and Pulp Hunter Whiteness Test Method).

[Opacity]
A basic sample (α) in which a black solid image portion is formed on the pseudo adhesive layer surface of the pseudo adhesive paper according to Comparative Example 1 by a laser printer (IPSiO NX6505: manufactured by RICOH), and the pseudo adhesive paper according to Comparative Example 1 A basic sample (β) on which nothing is printed on the surface of the pseudo adhesive layer is prepared, and Examples 1 to 13 and Comparative Examples 1 to 8 are applied to the surface of the pseudo adhesive layer of the basic sample (α). The pseudo-adhesive layer surface of each of the pseudo-adhesive papers is pseudo-adhered as a measurement sample (γ), and Examples 1 to 13 and Comparative Examples 1 to 8 are applied to the pseudo-adhesive layer surface of the basic sample (β). A sample for measurement (λ) was obtained by pseudo-adhering the pseudo-adhesive layer surface of each pseudo-adhesive paper.
Then, the opacity was calculated by the following formula: opacity (%) = (whiteness of measurement sample (γ) / whiteness of measurement sample (λ)) × 100. The whiteness was measured according to JIS P 8123 (Paper and Pulp Hunter Whiteness Test Method).

[Concealment]
The test was performed by pseudo-bonding a sample printed with 5 characters of black ink with an ink-jet printer (Pixus 850i: manufactured by Canon Inc.) and an unprinted sample from the side opposite to the printed surface. It was determined whether the printed characters could be read visually. In the evaluation, “◯” indicates that the characters could not be visually read, “Δ” indicates that the characters were partially read, and “x” indicates that all the characters could be read.

[Toner transfer]
In the test, each example and each comparative example were cut into A4 size, a dedicated black toner was set in a laser printer (IPSiO NX6505: manufactured by RICOH), and the characters “Daio Paper” were printed at 10 points. It was visually confirmed whether or not the printed characters were faint. Evaluation is good (○) if the blur could not be confirmed, some blur can be confirmed in part of the character, but enough can be distinguished (△) It can be confirmed by fading to the character and character discrimination is insufficient A thing was evaluated as impossible (×).

[Heat dissipation]
With a high-speed NIP printer (infoprint 4000: manufactured by IBM), 2,000 pages of form paper having a 13-inch width and a folding line formed every 12 inches in the paper flow direction are continuously printed, and according to the above folding line. The paper was discharged so that it was folded up every 12 inches. A thermometer was inserted between the 1000th and 1001th pages of the folded and laminated paper, and the temperature was measured 1 minute and 10 minutes after the end of printing. The recorded prints were 600 10-point numbers per page.

[Blocking etc.]
After the heat dissipation was measured, the page of the sample was turned, and it was visually confirmed whether or not the printing part was transferred to the white paper surface of the opposing surface, and whether or not blocking between the opposing printing parts occurred. . The evaluation is good (○) when there is no transfer or blocking of the toner to the opposing surface, and the blocking of the printing parts facing each other is confirmed slightly, but the toner transfer to the facing white paper surface is not confirmed, and the printing information Allowed to be judged that there is no problem in reading (△), blocking of the opposing printing parts and toner transfer to the opposing white paper surface were confirmed, and judging that there was a problem in reading the printing information was impossible (X).

  As can be seen from Table 1, Examples 1 to 13 of the present invention tend to have high opacity, excellent concealment properties, good heat dissipation of the paper, no toner blocking, etc., and no problem. . On the other hand, for Comparative Examples 1 to 8, information was not obtained using an electrophotographic printer, such as insufficient concealment, blocking or occurrence of toner transfer problems even when concealment was sufficient. It does not have sufficient performance as a pseudo-adhesive paper for recording.

  The present invention can be used for a label having confidentiality, an information hiding paper, a confidential postcard, a confidential envelope, and the like.

It is a figure for demonstrating an example of an uneven | corrugated pattern.

Explanation of symbols

  A ... A disconnection, B ... B disconnection.

Claims (7)

At least one side of the base paper has a pseudo-adhesive layer that can be peeled off when given conditions are given without being bonded under normal conditions, and characters / graphics are printed / printed on the surface of the pseudo-adhesive layer Is a so-called pre-glue type pseudo-adhesive paper,
Pseudo-adhesive paper characterized by having an arithmetic surface roughness Ra defined by JIS B 0601 measured by a stylus-type surface roughness measuring instrument defined by JIS B 0651 on the surface of the pseudo-adhesive layer of 3 to 15 μm .   The pseudo-adhesive paper according to claim 1, wherein the surface of the pseudo-adhesive layer is subjected to a roughening process.   3. A pseudo-adhesive paper, wherein information is recorded on a surface of the pseudo-adhesive layer of the pseudo-adhesive paper according to claim 1 by an electrophotographic recording apparatus.   The pseudo adhesive paper according to claim 3, wherein the pseudo adhesive layers are pseudo bonded. At least one side of the base paper has a pseudo-adhesive layer that can be peeled off when given conditions are given without being bonded under normal conditions, and characters / graphics are printed / printed on the surface of the pseudo-adhesive layer A so-called pre-glue type pseudo-adhesive paper manufacturing method,
It is specified in JIS B 0601 after applying a roughening treatment to the base paper, applying a pseudo-adhesive to the roughening treatment surface, and measuring with a stylus type surface roughness measuring instrument specified in JIS B 0651. A method for producing pseudo-adhesive paper, comprising forming a pseudo-adhesive layer surface having an arithmetic surface roughness Ra of 3 to 15 μm. At least one side of the base paper has a pseudo-adhesive layer that can be peeled off when given conditions are given without being bonded under normal conditions, and characters / graphics are printed / printed on the surface of the pseudo-adhesive layer A so-called pre-glue type pseudo-adhesive paper manufacturing method,
After applying the pseudo-adhesive to the base paper, the coated surface is subjected to a roughening treatment, and the arithmetic surface defined by JIS B 0601 is measured with a stylus type surface roughness measuring instrument defined by JIS B 0651. A method for producing pseudo-adhesive paper, comprising forming a pseudo-adhesive layer surface having a roughness Ra of 3 to 15 µm.   The information is recorded on the pseudo-adhesive layer surface of the pseudo-adhesive paper according to claim 5 or 6 by an electrophotographic recording apparatus, and then folded so that the information recording surface is on the inner surface side, and a predetermined pressure is applied to simulate the information. A method for producing pseudo-adhesive paper, characterized in that adhesive layers are pseudo-adhered to each other.

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