JP5885643B2 - Medium quality printing paper and its manufacturing method - Google Patents

Description

  The present invention relates to a medium-size printing paper having a high specific volume, high printing durability, and high printing density, and a method for producing the same.

  In recent years, bulkiness is one of the important qualities required for paper products. With the recent increase in environmental protection, it has become important to make the most effective use of paper pulp produced from forest resources. Therefore, users are demanding paper products that are lighter while maintaining the thickness of the paper.

  Conventionally, as one method for increasing the specific volume of paper, there is the use of bulky pulp. Wood pulp is generally used as a pulp for papermaking. However, compared with chemical pulp extracted from lignin, which is a reinforcing material in wood fibers, using chemicals, the wood is refined using ground pulp or refiner that grinds the wood with a grinder. It is known that mechanical fibers such as refiner mechanical pulp, thermomechanical pulp, and the like have more rigid fibers and are effective in reducing the density of paper. However, when hardwood is used as a raw material, the specific volume does not increase to a desired level, and when softwood is used as a raw material, the specific volume is improved, but the smoothness tends to decrease, and the ink inking property during printing is poor. It was.

  Among mechanical pulps, conifer thermomechanical pulp has a relatively long fiber length and high rigidity, so that paper made from this as a raw material for pulp has a poor texture, smoothness is reduced, or offset printing There was a problem that the ink deposition of the ink became poor. Paper made from coniferous thermomechanical pulp has high rigidity, so the folding ability, which is one of the workability during offset printing, is reduced, and the printed and bound books are not easily turned. Thus, there has been a problem of improving so-called flexibility, which reduces the bending stiffness of printing paper. In addition, when the mechanical pulp is blended in a high amount, the strength of the paper surface is lowered, and the paper peeling or the piled up paper dust on the blanket occurs during printing.

  There is a proposal of a bulky medium-sized printing paper obtained by applying starch to a base paper using hardwood mechanical pulp and a bulking agent (see Patent Document 1). As described above, the mechanical pulp made from hardwood does not increase the specific volume, and simply applying starch does not increase the printing durability, and may not be effective at all due to the difference in application method. In addition, the bulking agent not only increases the specific volume of its components, but also has significantly different side effects. Therefore, it is necessary to limit its use, particularly when a drug is applied to the base paper.

  It is also known to use a bulking agent as a technique for increasing the specific volume of paper. As a known bulking agent, for example, a bulking agent for paper containing a specific alcohol and / or a polyoxyalkylene adduct thereof (see Patent Document 2), a nonionic surfactant (see Patent Document 3), a polyhydric alcohol A paper bulking agent comprising a fatty acid ester compound (see Patent Document 4) is known, and a technique in which these paper bulking agents are applied to paperboard is also disclosed (see Patent Document 5). Among these, as a non-surfactant bulking agent, a paper bulking agent containing at least one compound selected from a cationic compound having a specific structure, an amine, an acid salt of an amine and an amphoteric compound is disclosed. (See Patent Document 6). There is also a bulking agent of the fatty acid polyamide polyamine type.

JP 2005-163253 A International Publication No. 98/03730 Japanese Patent Laid-Open No. 11-200263 JP 11-350380 A JP 2000-282398 A JP-A-11-269799

  There is a limit to the improvement of specific volume by using these known bulking agents, and further increase in specific volume is desired. Against this background, there has been a demand for the development of medium-size printing paper with high specific volume, high printing durability, and high printing density.

  An object of the present invention is to provide a medium-size printing paper having a high specific volume, high printing durability, and high printing density.

As a result of intensive studies on the above problems, the present inventors apply a predetermined amount of polyvinyl alcohol to the surface of a base paper obtained by making a paper stock containing a softwood mechanical pulp beaten in a specific range and a bulking agent. As a result, a medium-size printing paper having a high specific volume, a high printing durability, and excellent ink deposition properties has been completed. That is, at least one surface of a base paper obtained by making a paper stock containing 50 to 100% by mass of softwood mechanical pulp beaten to 100 to 400 cc of freeness with respect to the total pulp and having a bulking agent as an essential component. In a paper coated with 0.1 to 1.0 g / m ² per side of polyvinyl alcohol (hereinafter sometimes referred to as “PVA”), the air resistance is 10 seconds or more and the density is 0.40. It is characterized by being 0.50 g / cm ³ .

  In the present invention, the bulking agent is preferably a polyoxyalkylene alkyl ether or a nonionic surfactant.

  Moreover, it is preferable that the addition rate of the bulking agent with respect to the absolute dry weight of all the pulp is 0.2-1.0 mass% in solid content.

  The medium-quality printing paper of the present invention is characterized by high specific volume, high printing durability, and high printing density.

  Examples of the softwood mechanical pulp used in the present invention include known ground pulp, refiner groundwood pulp, thermomechanical pulp, chemithermomechanical pulp, bleached chemithermomechanical pulp, and the like.

  The softwood mechanical pulp used in the present invention is blended with a freeness of 80 to 400 cc by beating. From the viewpoint of easily controlling the air resistance described later, it is preferably 100 cc to 400 cc, for example, 80 to 300 cc. More preferably, they are 100cc-200cc, 120cc-200cc. If it is less than 80 cc, the fiber itself becomes too fine and does not reach the desired specific volume. If it exceeds 400 cc, the formation becomes worse, and the air resistance decreases during printing, resulting in a decrease in printing density.

  In the present invention, 40 to 100% by mass of the softwood mechanical pulp in the above-described freeness range is blended to make a base paper. Preferably it is 50-100 mass%, Furthermore, 70-100 mass%. More preferably, it is 85-100 mass%. The higher the blending ratio of the softwood mechanical pulp, the easier it is to obtain a paper having a high specific volume while maintaining various strengths of the paper. If the blending ratio of the conifer mechanical pulp with respect to the total pulp is less than 50% by mass, the desired specific volume is not reached. Moreover, when printing aptitude is considered, you may mix | blend 40-95 mass% with respect to all the pulp. In addition to softwood mechanical pulp, chemical pulp such as hardwood bleached kraft pulp, softwood bleached kraft pulp, hardwood ground pulp, refiner groundwood pulp, thermomechanical pulp, chemithermomechanical pulp, bleached chemithermomechanical pulp, etc. Wood pulp such as ink pulp and non-wood pulp such as kenaf, bagasse, bamboo, and cotton can be mixed and used at less than 60 parts by mass. Synthetic fibers can also be used as long as the quality is not affected.

  The medium-size printing paper of the present invention may contain a filler. A conventionally well-known thing can be used as a filler. Examples of fillers include calcium carbonate, talc, kaolin, calcined kaolin, titanium, and synthetic silica, which can be used alone or in combination. Calcium carbonate is preferable for improving the specific volume, and light calcium carbonate is more preferable among the calcium carbonates. The filler ratio in the medium-size printing paper is preferably 3 to 15% by mass, and more preferably 5 to 12% by mass. If the amount is less than 3% by mass, the ink deposition deteriorates. If the amount exceeds 15% by mass, the desired specific volume cannot be achieved, and the printing durability is also inferior. Since it is easy to improve a specific volume, it is preferable to use 70 mass parts or more in all the fillers as light calcium carbonate.

  The medium quality printing paper of the present invention contains a bulking agent. As the bulking agent, polyoxyalkylene alkyl ether or nonionic surfactant is preferred. As the polyoxyalkylene alkyl ether, a higher alcohol is particularly preferable. Nonionic surfactants include non-ionic surfactants such as fat-based nonionic surfactants, sugar alcohol-based nonionic surfactants, sugar-based nonionic surfactants, polyhydric alcohol-type nonionic surfactants, etc. Surfactants and the like. Other polyhydric alcohol and fatty acid ester compounds, polyoxyalkylene compounds of higher fatty acids, polyoxyalkylene adducts of polyhydric alcohol and fatty acid ester compounds, fatty acid amides, hydroxyethyl derivatives of fatty acid amides, fatty acid polyamide amine epichlorohydrin It can be used as a known bulking agent such as a reaction product or fatty acid polyamidoamine. These bulking agents may be used alone or in combination of two or more. In particular, by using a polyoxyalkylene alkyl ether or a nonionic surfactant, the water absorbability of the base paper is increased, and as a result, the PVA applied to the base paper penetrates into the base paper appropriately, and the printing durability at the time of printing is increased. Can be improved.

  In the present invention, the addition ratio of the bulking agent contained in the paper is preferably 0.2 to 1.0 mass% in terms of solid content with respect to the absolute dry weight of the whole pulp. From the viewpoint of easily maintaining a balance between the specific volume of the paper and the printing durability, the content is more preferably 0.2 to 0.7% by mass. If it is less than 0.2% by mass, the desired specific volume may not be achieved. If the solid content exceeds 1.0% by mass, the strength of the paper including the printing durability tends to be lowered, and the papermaking process may become dirty and it may be difficult to produce the paper substantially.

  Moreover, since these bulking agents have relatively poor fixability to pulp fibers, it is preferable to add a cationic substance to the paper stock in order to improve the fixing rate. In particular, polyoxyalkylene alkyl ethers and nonionic surfactants are poor in fixability, so it is desirable to mix a cationic substance and add it to the paper. As the cationic substance, a cationic starch, a sulfuric acid band, a cationic retention agent, a cationic surfactant such as an alkyl quaternary ammonium salt, and the like are preferable. The bulking agent has different fixing properties to the pulp fiber depending on the type, and the fixing rate to the pulp fiber when the cationic substance is not mixed in the paper stock is, for example, about 60% in the case of a fatty acid amide based bulking agent. Sometimes. Further, in the case of a polyoxyalkylene alkyl ether and a nonionic surfactant, it may be about 30%. If a bulking agent with high fixability to pulp fibers is used, it is not easy to increase the specific volume of the paper, but by increasing the fixing rate of each bulking agent, the amount of bulking agent added to the pulp is relatively small. Even if it exists, it becomes easy to obtain a bulky effect.

  In the medium-size printing paper of the present invention, in addition to pulp, filler and bulking agent, paper strength enhancer, sizing agent, yield improver, drainage improver, sulfuric acid band, wet paper strength enhancer, colored dye, color pigment In addition, a known papermaking material such as a fluorescent brightener, a fluorescent decoloring agent, and a pitch control agent can be appropriately used as long as the effects of the present invention are not impaired. As the paper strength enhancer, a conventionally known paper strength enhancer can be used, such as starch based paper strength enhancer, polyacrylamide based paper strength enhancer, starch graft polymerization polyacrylamide based paper strength enhancer, etc. Can be illustrated.

In the present invention, a sizing liquid containing PVA is applied to at least one surface of the paper and dried. Applying PVA not only increases the printing durability of the paper surface, but also coats it like a film and increases the air resistance, so that the printing ink does not enter the paper excessively and the ink density increases and looks good. The print finishes. In addition, starch, a polyacrylamide paper strength enhancer, a surface sizing agent, a conductive agent, a coloring dye, a coloring pigment, a fluorescent brightening agent, and the like may be blended with PVA to the extent that the present invention is not hindered. PVA is applied to the paper surface at 0.08 to 1.5 g / m ^{2 in} terms of solid content per side. From the viewpoint of easily maintaining the balance of the specific volume of paper, air permeability resistance and printing durability, 0.1 to 1.0 g / m ² , further 0.2 to 0.8 g / m ² , and further 0.4 to It is preferable to apply 0.7 g / m ² . If it is less than 0.08 g / m ² , the desired printing durability will not be achieved, and the desired air resistance will not be achieved, resulting in a decrease in printing density. If it exceeds 1.5 g / m ² , not only does the specific volume not increase due to an increase in the paper weight, but it is also necessary to increase the concentration of PVA. It becomes difficult. The PVA used here preferably has a molecular weight of 800 to 4000, for example 1000 to 2000, in order to obtain the printing durability and the appropriate viscosity of the sizing liquid, and is preferably a fully saponified PVA rather than a partially saponified PVA.

  In the present invention, the sizing liquid is preferably applied by a transfer type coating machine represented by a gate roll coater, a rod metering type sizer or the like. Especially when polyoxyalkylene alkyl ethers or nonionic surfactants are used, the water absorption of the paper increases. Therefore, in the case of a pond type size press or a method of applying directly to paper and scraping it off, excessive absorption of the size liquid is excessive. As a result, the drying load of the dryer increases, and as a result, the efficiency is greatly reduced, and it may be difficult to produce substantially.

  The paper making method in the present invention is not particularly limited, and a long net paper machine, a long net multi-layer paper machine, a circular net paper machine, a circular net multi-layer paper machine, a long net circular net combination multi-layer paper machine, a twin wire paper machine, etc. Manufactured by various devices. As the papermaking method, either acidic papermaking or neutral papermaking can be selected. When calcium carbonate is highly blended as a filler, it becomes neutral papermaking.

  The air resistance of the medium-size printing paper of the present invention is 10 seconds or more. The air resistance can be controlled by a combination of freeness control by beating the pulp, press of a paper machine and linear pressure control such as a calendar. In addition, the use of a bulking agent, the combination of filler type and blending amount, etc. can also affect the air resistance. The freeness of the softwood mechanical pulp is preferably 100 cc to 400 cc, more preferably 120 cc to 300 cc. If the freeness is less than 100 cc, the desired specific volume is not reached. If it exceeds 400 cc, the paper layer strength may decrease and problems may occur during printing, the desired air resistance cannot be reached, and as a result, the penetration of printing ink into the paper increases and the printing density decreases. . The air resistance is 10 seconds or more, preferably 15 seconds or more, and more preferably 20 seconds or more.

The density of the medium-size printing paper of the present invention is 0.40 to 0.50 g / cm ³ . If it is less than 0.40 g / cm ³ , the inter-fiber voids become excessive, resulting in a decrease in printing strength, and a desired air permeability cannot be maintained, resulting in a decrease in printing density. If it exceeds 0.50 g / cm ³ , the paper itself becomes hard and cannot meet the weight reduction demanded by the user.

  For the purpose of controlling the air permeability of the medium-size printing paper of the present invention, it is preferable to perform processing by a known calendar device such as a paper machine press, a machine calendar, a super calendar, or a soft calendar.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Further, “parts” and “%” shown in the examples indicate solid parts by mass and solids mass% unless otherwise specified. The obtained medium-size printing paper was tested based on the evaluation method as shown below.

<Air permeability resistance>
Measured according to JIS P 8117: 1998.

<Measurement of MA value>
The MA value was also measured and calculated as an index of ink fillability. The MA value of the medium-size printing paper of the present invention can be 1.0 or less, and is preferably 0.8 or less, and more preferably 0.6 or less, from the viewpoint of improving the ink deposition property. For the measurement, PST2600 (manufactured by FIBRO system ab) was used, and the ratio of the total area of non-contact portions of 0.16 mm ² or more to the measurement portion area was determined as MA value (%). The clamping pressure condition at this time was 3.4 MPa, and the clamping time was 0.02 seconds.

Specifically, the paper was clamped at a set clamping pressure and a set time, and light was applied obliquely from above with the surface of the paper pressed against the prism. The reflected light was read with an upper CCD camera. The contact / non-contact area between the prism surface and the paper surface was calculated from the measured image using a dedicated image analysis platform and a dedicated program attached to a commercially available personal computer. Since the non-contact area is classified according to the area, data correlating with the lack of the image line portion due to poor inking is obtained. If there are many non-contact parts with a large area, the printing ink is difficult to fix and tends to cause chipping of the printed part. Based on the above principle, it is possible to perform surface state measurement more directly than the so-called air leak method smoothness measurement method. In this invention, MA value was calculated | required with the following formula.
MA value (%) = 0.16mm ² or more of the total area of the non-contact portion (mm ²⁾ ÷ measuring portion area (mm ²⁾ × 100
Here, the measurement part area is an area of an actual measurement part to which light is applied in the pressing surface of the prism.

<Basis weight>
It measured based on JIS P8124: 1998.

<Thickness and density>
It measured based on JISP8118: 1998.

<Freeness>
Based on JIS P8121: 1995, it was measured by a Canadian standard freeness test method.

  Ryobi “Ryobi 3302M” is used as a printing machine, printing one color with black ink (Values G black: manufactured by DIC) at a printing speed of 8500 sheets / hour for printing durability and ink fillability. evaluated.

<Press life>
(Double-circle): There is almost no dirt of a blanket and it is good.
○: The blanket is slightly dirty, but there is almost no void in the image area, which is good.
Δ: Many blankets are smudged, white areas in the image area are missing, and practically lower limit level.
×: The blanket is severely soiled and there are many white spots in the image area.

<Print density>
A: The printing density is high, and there is no ink unevenness.
○: The printing density is high, but there is a slight unevenness in ink deposition. No problem level.
(Triangle | delta): A printing density is a little high and there is also ink unevenness unevenness a little. Practical lower limit level.
X: The printing density is low and the ink inking unevenness is large and practically impossible.

Example 1
The pulp slurry was made up of 80 parts by weight of softwood mechanical pulp beaten to 200 cc freeness and 20 parts by weight hardwood bleached chemical pulp (LBKP) beaten to 400 cc freeness. 0.7 parts by weight of food processing company), 7 parts by weight of calcium carbonate (trade name: TP121 / Okutama Kogyo Co., Ltd.) as a filler, bulking agent (trade name: KB85 (polyoxyalkylene alkyl ether of higher alcohol) / Kaosha 0.5 parts by mass) and 0.01 parts by mass of a yield improver (trade name: HHC503 / Kurita Kogyo Co., Ltd.) were added to prepare a paper stock. This stock is made with an on-top type twin-wire paper machine, and with a rod metalling sizer, PVA (trade name: PVA117 / manufactured by Kuraray) 5%, oxidized starch (trade name: MS3800 / Nippon Shokuhin Kako) (Manufactured) A 10% surface size liquid was applied and dried so that the solid mass per side was 1.5 g / m ^2, and the flattening treatment was adjusted at a linear pressure of 40 kN / m using a machine calendar, and the basis weight was 70 g / m ^2. m ² medium-quality printing paper was obtained. The coating amount per side of PVA was 0.5 g / m ² in terms of solid mass.

(Example 2)
A medium-sized printing paper was obtained in the same manner as in Example 1 except that the freeness of the softwood mechanical pulp was changed from 200 cc to 100 cc.

(Example 3)
A medium quality printing paper was obtained in the same manner as in Example 1 except that the freeness of the softwood mechanical pulp freeness was changed from 200 cc to 400 cc.

Example 4
Medium quality printing paper as in Example 1 except that the blending amount of the conifer mechanical pulp was changed from 80 parts by weight to 50 parts by weight and the blending amount of the hardwood bleached chemical pulp was changed from 20 parts by weight to 50 parts by weight. Got.

(Example 5)
Medium-sized printing paper in the same manner as in Example 1 except that the blending amount of the conifer mechanical pulp was changed from 80 parts by mass to 100 parts by mass and the blending amount of the hardwood bleached chemical pulp was changed from 20 parts by mass to 0 parts by mass. Got.

(Example 6)
The surface size liquid applied to the paper surface was changed to a surface size liquid of PVA (trade name: PVA117 / manufactured by Kuraray Co.) 1% and oxidized starch (trade name: MS3800 / manufactured by Nippon Shokuhin Kako Co., Ltd.) 10%. A medium-size printing paper was obtained in the same manner as in Example 1. The coating amount per side of PVA was 0.1 g / m ² in terms of solid mass.

(Example 7)
The surface sizing liquid applied to the paper surface was changed to a surface sizing liquid of PVA (trade name: PVA117 / Kuraray) 10%, oxidized starch (trade name: MS3800 / manufactured by Nippon Shokuhin Kako), 1%, A medium-size printing paper was obtained in the same manner as in Example 1. The coating amount per side of PVA was 1.0 g / m ² in terms of solid mass.

(Example 8)
The surface size liquid applied to the paper surface was changed to a surface size liquid of 5% PVA (trade name: PVA117 / Kuraray Co., Ltd.) and 0% oxidized starch (trade name: MS3800 / manufactured by Nippon Shokuhin Kako Co., Ltd.) A medium-size printing paper was obtained in the same manner as in Example 1. The coating amount per side of PVA was 0.5 g / m ² in terms of solid mass.

Example 9
A medium-sized printing paper was obtained in the same manner as in Example 1 except that the sizing liquid coating method was changed from the rod metalling type sizer to the gate roll coater.

(Example 10)
Except having changed the addition rate of the bulking agent (trade name: KB85 (polyoxyalkylene alkyl ether of higher alcohol) / manufactured by Kao Corporation) from 0.5 parts by mass to 0.2 parts by mass, the same as in Example 1 A medium quality printing paper was obtained.

(Example 11)
Except for changing the addition rate of the bulking agent (trade name: KB85 (polyoxyalkylene alkyl ether of higher alcohol) / manufactured by Kao Corporation) from 0.5 parts by mass to 1.0 part by mass, the same procedure as in Example 1 was performed. A medium quality printing paper was obtained.

(Example 12)
0.5 parts by mass of a bulking agent (trade name: KB85 (polyoxyalkylene alkyl ether of higher alcohol) / manufactured by Kao Corporation) is added to a bulking agent (trade name: PT8107 (fatty acid amide resin) / manufactured by Seiko PMC). A medium-size printing paper was obtained in the same manner as in Example 1 except that the content was changed to 5 parts by mass.

(Comparative Example 1)
A medium quality printing paper was obtained in the same manner as in Example 1 except that the softwood mechanical pulp was not used and the blending amount of the hardwood bleached chemical pulp was changed from 20 parts by mass to 100 parts by mass.

(Comparative Example 2)
A medium quality printing paper was obtained in the same manner as in Example 1 except that the softwood mechanical pulp and the hardwood bleached chemical pulp were not used, and instead 100 parts by weight of the hardwood mechanical pulp was blended.

(Comparative Example 3)
A medium-sized printing paper was obtained in the same manner as in Example 1 except that the freeness of the softwood mechanical pulp was changed from 200 cc to 50 cc.

(Comparative Example 4)
A medium-sized printing paper was obtained in the same manner as in Example 1 except that the softwood mechanical pulp was used without beating. The freeness of the softwood mechanical pulp at this time was 550 cc.

(Comparative Example 5)
The surface sizing liquid applied to the paper surface was changed to a surface sizing liquid of PVA (trade name: PVA117 / Kuraray Co., Ltd.) 0% and oxidized starch (trade name: MS3800 / Nihon Shokuhin Kako Co., Ltd.) 10%, A medium-size printing paper was obtained in the same manner as in Example 1.

(Comparative Example 6)
A medium-size printing paper was obtained in the same manner as in Example 1 except that the machine calendar was bypassed and the flattening adjustment was not performed.

  From the results of Examples 1 to 12, a desired density and air resistance are obtained by applying a predetermined amount of softwood mechanical pulp and a predetermined amount of PVA, and applying a predetermined amount of PVA. A high-density medium-size printing paper could be obtained.

  Comparative Examples 1, 2 and 3 did not reach the desired density. In Comparative Example 4, although the desired density was achieved, the printing durability and the printing density during printing were low, and thus could not be used. In Comparative Example 5, since PVA was not used for the surface sizing liquid, the printing durability was greatly reduced and could not be used. In Comparative Example 6, since the flattening treatment was not performed, the smoothness of the surface was lowered, the printing density was low, and the uneven unevenness was large, so that it could not be used.

  As is clear from Table 1, by applying a predetermined amount of softwood mechanical pulp and a predetermined amount of PVA and applying a predetermined amount of PVA, the desired density and air resistance are obtained, the printing durability during printing is high, and the printing density Was able to obtain high-quality medium-size printing paper. Further, it was found that the medium-quality printing paper of the present invention has a desired MA value and excellent ink deposition properties.

Claims (6)

A medium-size printing paper mainly composed of pulp, wherein 40 to 100% by mass of the pulp is a softwood mechanical pulp having a freeness of 100 to 400 cc, contains a bulking agent, and polyvinyl alcohol is at least one of the paper The surface is coated with 0.08 to 1.5 g / m ^{2 in} terms of solid content per side, the polyvinyl alcohol is completely saponified polyvinyl alcohol, the air resistance is 10 seconds or more, and the density is 0. A medium-size printing paper characterized by being 40 to 0.50 g / cm ³ .   2. The medium quality printing paper according to claim 1, wherein the bulking agent is a polyoxyalkylene alkyl ether or a nonionic surfactant.   The medium-size printing paper according to claim 1 or 2, wherein the addition ratio of the bulking agent to the absolute dry weight of the whole pulp is 0.2 to 1.0 mass% in terms of solid content. The medium weight printing paper according to any one of claims 1 to 3, wherein the molecular weight of the polyvinyl alcohol is 800 to 4000. The medium-quality printing paper according to any one of claims 1 to 4, comprising 3 to 15% by mass of calcium carbonate as a filler. Wood containing printing method for producing a sheet according to any one of claims 1-5, characterized in that coated using the transfer type coating machine the polyvinyl alcohol.