JP2007092170A - Aluminum alloy plate for lithographic printing plate and method for production thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aluminum alloy plate for use in a lithographic printing plate, which has a more even pit formed thereon by an electrochemical surface roughening treatment and ensures better adhesion to a photosensitive film and better water-retentivity. <P>SOLUTION: An aluminum alloy plate having the following composition: Mg: 0.1 to 1.5%; Zn: more than 0.05% and not more than 0.5%; Fe: 0.1 to 0.6%; Si: 0.03 to 0.15%; Cu: 0.0001 to 0.10%; Ti: 0.0001 to 0.05%; and remainder: aluminum and impurities, provided that the relationship between the Mg content and the Zn content is defined as follows: 4×Zn%-1.4%≤Mg%≤4×Zn%+0.6%, wherein the amount of aluminum powder on the surface of the plate is adjusted to 0.1 to 3.0 mg/m<SP>2</SP>. It is more effective that the precipitate having a diameter (equivalent circular diameter) of 0.1 to 1.0 μm is dispersed on the surface of the plate at a density of 10,000 to 100,000 particles/mm<SP>2</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aluminum alloy plate for a lithographic printing plate, in particular, an aluminum alloy plate for a lithographic printing plate that can be uniformly roughened by electrochemical etching treatment, and has excellent strength and heat-softening property, And a manufacturing method thereof.

  In general, an aluminum alloy plate is used as a support for lithographic printing plates (including offset printing plates), and the support is rough from the viewpoint of improving the adhesion of the photosensitive film and improving the water retention of the non-image area. Processing is performed. Conventionally, as the surface roughening method, mechanical surface roughening methods such as ball graining, brush graining, and wire graining have been carried out. Since a continuous treatment with a material is possible, a method for roughening the surface of an aluminum alloy plate for a support by an electrochemical etching process has been rapidly developed.

  The electrochemical etching treatment uses an electrolytic solution mainly composed of hydrochloric acid or hydrochloric acid (hereinafter referred to as a hydrochloric acid-based electrolytic solution) or an electrolytic solution mainly composed of nitric acid or nitric acid (hereinafter referred to as a nitric acid-based electrolytic solution). A material equivalent to A1050 (aluminum purity 99.5%), which can obtain a relatively uniform electrolytic surface roughening, is applied as a support, and 10 can be obtained by appropriately selecting a photosensitive layer coated on the support. It is possible to obtain tens of thousands of clear printed materials.

  In addition, in order to improve the printing durability of the printing plate, the printing plate having an aluminum alloy plate as a support is exposed and developed by a normal method, and then heat-treated at a high temperature (burning treatment). Strengthening has been done. Since the burning treatment is usually performed under the conditions of a heating temperature of 200 to 290 ° C. and a heating time of 3 to 9 minutes, heat resistance (burning resistance) is required so that the strength of the support does not decrease during the burning treatment. It has been.

  In addition, recently, with the advance of printing technology, the printing speed has increased and the strength against the support has increased in response to the increased stress applied to the printing plates that are mechanically fixed to both sides of the printing press cylinder. When the demand is increasing and the support strength is insufficient, the fixed portion is deformed or damaged, resulting in troubles such as printing misalignment. Therefore, it is indispensable to improve the strength of the support along with the above-mentioned burning resistance. .

In order to satisfy such requirements, an aluminum alloy support in which additive components are adjusted based on an A1050 equivalent material has been proposed (for example, see Patent Document 1). Attempts have also been made to achieve the object by adjusting the additive components based on the A1050 equivalent material and adjusting the oil pit depth on the plate surface (see Patent Document 2).
JP 2005-15912 A JP 2004-35936 A

  In order to further improve the above-mentioned proposals, the inventors used an aluminum alloy support based on a material equivalent to A1050, and finally the surface properties and electrolytic surface roughening treatment of the cold-rolled rolled sheet. The relationship with the etching pit obtained by this was repeatedly investigated. In the process, it was found that the aluminum powder remaining on the surface of the rolled plate affects the formation of etching pits, and a uniform pit pattern can be obtained by regulating the amount of aluminum powder.

  The present invention was made as a result of further examination and examination based on the above findings, and its purpose is to provide a more excellent photosensitive film in which more uniform pits are formed by electrochemical surface roughening treatment. It is intended to provide an aluminum alloy plate for a lithographic printing plate and a method for producing the same, which can obtain high adhesion and water retention and is excellent in heat softening resistance (burning resistance).

In order to achieve the above object, an aluminum alloy plate for a lithographic printing plate according to claim 1 has Mg: 0.1 to 1.5%, Zn: 0.5% or less, Fe: 0.1 to 0.6% Si: 0.03 to 0.15%, Cu: 0.0001 to 0.1%, Ti: 0.0001 to 0.1%, an aluminum alloy plate having a composition composed of the balance aluminum and impurities The amount of aluminum powder on the plate surface is adjusted to 0.1 to 3.0 mg / m ² .

The aluminum alloy plate for a lithographic printing plate according to claim 2 has Mg: 0.1 to 1.5%, Zn: more than 0.05% and 0.5% or less, Fe: 0.1 to 0.6%, Si : 0.03-0.15%, Cu: 0.0001-0.10%, Ti: 0.0001-0.05%, the relationship between the Mg content and the Zn content is 4 × Zn% -1.4% ≦ Mg% ≦ 4 × Zn% + 0.6%, an aluminum alloy plate having a composition comprising the balance aluminum and impurities, and the amount of aluminum powder on the plate surface is 0.1 to 3.0 mg / characterized in that it is adjusted to m ^2.

An aluminum alloy plate for a lithographic printing plate according to claim 3 is the aluminum alloy plate according to claim 2, wherein a precipitate having a diameter (equivalent circle diameter) of 0.1 to 1.0 μm is 10,000 to 100,000 on the surface of the aluminum alloy plate. It is characterized by being dispersed per piece / mm ² .

  An aluminum alloy plate for a lithographic printing plate according to claim 4 is characterized in that, in claim 2 or 3, the solid solution amount of Fe in the aluminum alloy plate is 20 to 100 ppm.

  The aluminum alloy plate for a lithographic printing plate according to claim 5 is the aluminum alloy plate according to any one of claims 2 to 4, wherein a part or all of the constituent elements of the aluminum alloy plate forms an intermetallic compound. The amount of Fe being formed is 50 to 99.8% of the total amount of Fe, and the amount of Si forming the intermetallic compound is 5 to 40% of the total amount of Si, forming an Al-Fe intermetallic compound. The ratio (B% / A%) of the Fe amount (B%) forming the Al—Fe—Si intermetallic compound to the Fe amount (A%) is 0.9 or less.

The aluminum alloy plate for a lithographic printing plate according to claim 6 is the surface of the aluminum alloy plate according to any one of claims 1 to 5, wherein the number of oil pits having a diameter (equivalent circle diameter) of 30 μm or more is 50 / mm. ^{It is 2} or less.

  An aluminum alloy plate for a lithographic printing plate according to claim 7 according to any one of claims 1 to 6, wherein the aluminum alloy plate further contains Mn: more than 0.05% and not more than 0.3%. To do.

  An aluminum alloy plate for a lithographic printing plate according to claim 8 is the plate according to any one of claims 1 to 7, wherein an average crystal grain length in a direction orthogonal to the rolling direction as viewed from the plate surface of the aluminum alloy plate is 100 μm or less. The average crystal grain length in the direction parallel to the rolling direction as viewed from the surface is 2 to 20 times the average crystal grain length in the direction orthogonal to the rolling direction.

  An aluminum alloy plate for a lithographic printing plate according to claim 9 is the aluminum alloy plate according to any one of claims 1 to 8, wherein the aluminum alloy plate further contains one or more elements selected from Pb, In, Sn, and Ga. It is contained within the range of 0.005 to 0.05%.

  The aluminum alloy plate for a lithographic printing plate according to claim 10 is characterized in that in any one of claims 3 to 9, the 0.2% proof stress after heat treatment at 270 ° C. for 7 minutes is 120 MPa or more.

  A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 11 is to ingot the aluminum alloy having the composition according to any one of claims 2, 7, and 9, and to obtain a rolled surface surface layer of the obtained ingot. After chamfering -15mm, heat to a temperature range of 450-580 ° C at a temperature increase rate of 20-60 ° C / hr and perform a homogenization treatment for 1 hour or more, then start temperature is 400-520 ° C, end temperature The temperature is set to 320 to 400 ° C., and the thickness at the end is 5 mm or less, and cold rolling is performed without performing intermediate annealing.

  According to a twelfth aspect of the present invention, there is provided a method for producing an aluminum alloy plate for a lithographic printing plate comprising ingot-making an aluminum alloy having the composition according to any one of the second, seventh and ninth aspects, After 15 mm chamfering, the material is heated to a temperature range of 450 to 580 ° C. at a temperature increase rate of 20 to 60 ° C./hr and held for 1 hour or more, and then the temperature is once lowered to room temperature and then 350 to 350 ° C. Hot rolling is started by heating to a temperature of 500 ° C., the end temperature is set to 300 to 380 ° C., the thickness at the end is set to 5 mm or less, and cold rolling is performed without performing intermediate annealing. It is characterized by that.

  According to a thirteenth aspect of the present invention, there is provided a method for producing an aluminum alloy plate for a lithographic printing plate comprising ingoting an aluminum alloy having the composition according to any one of the second, seventh and ninth aspects, After chamfering ~ 15mm, heat to 450 ~ 580 ° C and hold for 3 hours or more, and lower the temperature from the holding temperature to the hot rolling start temperature at a temperature drop rate of 20 ~ 60 ° C / hr. Then, hot rolling is performed so that the start temperature is 400 to 500 ° C., the end temperature is 300 to 400 ° C., the thickness at the end is 5 mm or less, and cold rolling is performed without performing intermediate annealing. .

  A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 14 is a method for producing an aluminum alloy plate for a lithographic printing plate according to claim 1 or 2, wherein the rolling oil has a viscosity of 1 to 6 cSt in the final cold rolling. It is characterized by using.

  A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 15 is a method for producing an aluminum alloy plate for a lithographic printing plate according to claim 1 or 2, wherein the Mg content (Mg%) and the final cold rolling In the final cold rolling, a rolling oil satisfying −2 × Mg% + 2 ≦ ρ ≦ −2 × Mg% + 8 in relation to the viscosity ρ of the rolling oil used in is used.

  The method for producing an aluminum alloy plate for a lithographic printing plate according to claim 16 is a method for producing the aluminum alloy plate for a lithographic printing plate according to claim 6, wherein the roll surface roughness is an arithmetic average roughness in the final cold rolling. Ra: A rolling roll having a thickness of 0.2 to 0.5 μm is used, and cold rolling is performed using a rolling oil having a viscosity of 1 to 6 cSt.

  A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 17 is a method for producing an aluminum alloy plate for a lithographic printing plate according to claim 6, wherein the Mg content (Mg%) and the viscosity ρ of the rolling oil are The rolling oil satisfying ρ ≦ 2 × Mg + 4 is used in the final cold rolling.

  According to the present invention, more uniform pits are formed by the electrochemical surface roughening treatment, and it is possible to obtain better adhesion to the photosensitive film and water retention, and further improved image sharpness and printing durability. An aluminum alloy plate for a lithographic printing plate excellent in strength and heat softening resistance that makes it possible to achieve the above and a method for producing the same are provided.

  The significance and reasons for limitation of the components contained in the aluminum alloy plate for lithographic printing plates of the present invention will be described. Most of Mg functions as a solid solution in aluminum to improve strength and heat softening resistance. The strength is the tensile strength at normal temperature as a printing plate support, and 160 MPa or more is a practically preferable range. Heat softening resistance, also called burning resistance, is 0.2% proof stress after being heated at a temperature of about 280 ° C., and 90 MPa or more is a practically desirable range. The preferable content of Mg is in the range of 0.1 to 1.5%. If the content is less than 0.1%, the effect is not sufficient. If the content exceeds 1.5%, the uniformity of pits in the surface roughening treatment is insufficient. It becomes low and the stain | pollution | contamination of a non-image part tends to arise.

  Zn, like Mg, is mostly dissolved in aluminum, but does not contribute to the improvement of strength and heat-softening properties like Mg, and affects the oxide film formed on the aluminum surface. The oxide film formed on the aluminum surface includes an oxide film formed when left at room temperature (natural oxide film) and an oxide film formed during heat treatment in the manufacturing process, but Zn affects both. give.

  That is, in an aluminum alloy containing Mg, an oxide film mainly composed of Mg oxide (MgO-based oxide) is easily formed by heat treatment such as homogenization treatment, heating during hot rolling, and intermediate annealing. Since the oxide film is active and porous, the wettability with the treatment liquid is improved in the electrolytic surface-roughening treatment and the surface roughening is promoted, but the pits are likely to be non-uniform. The inclusion of Zn improves the unevenness of the roughened structure and functions to suppress activation by Mg oxide. The preferable content of Zn is in the range of 0.5% or less. If the content exceeds 0.5%, the effect of suppressing activation by the Mg oxide is increased, and the roughening becomes uneven. Intermetallic compounds are easily formed, and coarse pits are formed during the electrolytic treatment, which further hinders the uniformity of the roughening. A more preferable content range of Zn is more than 0.05% and 0.5% or less, and a more preferable content range of Zn is 0.06 to 0.5%.

  Fe produces an Al—Fe-based intermetallic compound, and coexists with Si to produce an Al—Fe—Si-based intermetallic compound. The dispersion of these compounds refines the recrystallized structure. The compound serves as a starting point of pit generation, uniformizing pit formation during the electrolytic treatment, and finely distributing the pits. The preferable content of Fe is in the range of 0.1 to 0.6%. If the content is less than 0.1%, the distribution of the compound becomes non-uniform, and unetched portions are generated during the electrolytic treatment, thus preventing the formation of pits. Make uniform. If it exceeds 0.6%, a coarse compound is produced, and the uniformity of the roughened structure is lowered.

  Si coexists with Fe to produce an Al—Fe—Si intermetallic compound, and the dispersion of the compound refines the recrystallized structure, and these compounds serve as starting points for pit generation during the electrolytic treatment. Uniform formation of pits and fine distribution of pits. The preferable content of Si is in the range of 0.03 to 0.15%. If it is less than 0.03%, the distribution of the compound becomes non-uniform, and unetched portions are generated during the electrolytic treatment, thus preventing the formation of pits. Make uniform. If it exceeds 0.15%, a coarse compound is produced, and precipitation of simple Si is likely to occur, and the uniformity of the roughened structure is lowered.

  Cu is easily dissolved in aluminum and has an effect of refining pits in a content range of 0.0001 to 0.10%. If the content exceeds 0.10%, pits during electrolytic treatment are likely to be coarse and non-uniform, and unetched portions are likely to occur. It becomes easy to do. In addition, in this invention, the amount of Cu mixed from the metal | base metal employ | adopted in order to obtain content of the said Fe and Si is about 5-100 ppm (0.0005-0.01%).

  Ti refines the ingot structure and refines the crystal grains. As a result, pit formation during the electrolytic treatment is made uniform, and streaks are prevented when processing as a printing plate is performed. The preferable content of Ti is in the range of 0.0001 to 0.05%. When the content is less than 0.0001%, the effect is small. When the content exceeds 0.05%, a coarse Al-Ti compound is formed. As a result, the roughened structure tends to be non-uniform. In addition, when adding B with Ti for refinement | miniaturization of an ingot structure | tissue, it is preferable to contain Ti in 0.01% or less of range.

  Mn functions to improve strength and heat softening resistance. The preferable content of Mn is in the range of more than 0.05% and 0.3%, and the effect is small at 0.05% or less, and when it exceeds 0.3%, a coarse Al—Fe—Mn system or Al -Fe-Mn-Si-based intermetallic compounds are likely to be formed, and the surface roughening during the electrolytic treatment becomes non-uniform. A more preferable content range of Mn is 0.06 to 0.3%.

  In the aluminum alloy plate for lithographic printing plates according to the present invention, the Mg content and the Zn content satisfy the relationship of 4% × Zn% −1.4% ≦ Mg% ≦ 4 × Zn% + 0.6%. Desirably, by including Mg and Zn that satisfy this relationship, pit formation during the electrolytic treatment can be made more uniform, and an excellent roughened structure can be obtained. When 4 × Zn% −1.4%> Mg%, the Zn amount is excessive with respect to the Mg amount, so the effect of suppressing activation by the Mg oxide is increased, and the pit formation during the electrolytic treatment becomes uneven. Rough surface formation tends to be uneven. In the case of Mg%> 4 × Zn% + 0.6%, the Zn content is too small relative to the Mg content, so the activation suppressing action by Mg oxide is small. Formation is uneven and rough surface formation tends to be uneven.

  The aluminum alloy plate for a lithographic printing plate according to the present invention further improves electrolytic graining properties by adding 0.005 to 0.05% of one or more of Pb, In, Sn and Ga in a total amount. The desired pit pattern can be obtained with a small amount of electricity. If the total amount of one or more elements selected from the group consisting of Pb, In, Sn, and Ga is less than 0.005%, the effect is not sufficient, and if it exceeds 0.05%, the shape of the pit tends to collapse. Become.

An aluminum alloy plate for a lithographic printing plate according to the present invention is produced by ingot-making the aluminum alloy ingot by continuous casting or the like, and homogenizing the obtained ingot, followed by hot rolling and cold rolling. However, it is important to adjust the amount of aluminum powder on the surface of the rolled sheet after the final cold rolling to 0.1 to 3.0 mg / m ² . The aluminum powder is a powder of an aluminum alloy remaining on the surface of the rolled sheet generated from the aluminum alloy rolled material during the final cold rolling, and in the case of the aluminum alloy of the present invention containing Mg, the amount of aluminum powder If it is less than 0.1 mg / m ² , when wound as a coil after the final cold rolling, the effect of preventing scratches in the coil is insufficient, and if it exceeds 3.0 mg / m ² , aluminum powder is used in the degreasing process. Is not sufficiently removed and remains on the plate surface, and during the electrolytic surface roughening treatment, the pit formation is insufficient or uneven in the portion where the aluminum powder remains, and the appearance due to unetched parts and uneven patterns after electrolytic graining It causes a defect. Excessive aluminum powder can also cause line contamination.

  In order to adjust the amount of aluminum powder on the surface of the plate after the final cold rolling to the above range, in addition to adjustment to the above components, the final cold rolling degree of processing, the properties of the rolling oil, the supply of the rolling oil according to the composition It is necessary to adjust the amount. In particular, the viscosity of the rolling oil in the final cold rolling is important, and it is preferable to use a rolling oil having a viscosity of 1 to 6 cSt. If the viscosity is less than 1 cSt, the amount of rolling oil introduced between the rolling roll and the rolled material is reduced, resulting in poor lubrication, and excessive aluminum powder is likely to occur. When the viscosity exceeds 6 cSt, the amount of rolling oil introduced between the rolling roll and the rolled material becomes excessive, and the generation of aluminum powder tends to be reduced.

  As the rolling oil in the final cold rolling, the relationship between the Mg content (Mg%) in the aluminum alloy and the viscosity ρ of the rolling oil used in the final cold rolling is (−2 × Mg% + 2)> At ρ, since the deformation resistance is small and the amount of rolling oil introduced between the rolling roll and the rolled material is small, aluminum powder tends to be excessively generated. When ρ> (− 2 × Mg% + 8), the deformation resistance increases, the amount of rolling oil introduced between the rolling roll and the rolling material becomes excessive, and the generation of aluminum powder tends to be reduced.

In the present invention, on the surface of the plate, precipitates having a diameter (equivalent circle diameter) of 0.1 to 1.0 μm are dispersed by 10,000 to 100,000 / mm ² , so that more uniform etch pits can be obtained in the electrolytic treatment. Can be formed. If the number of precipitates is less than 10,000 pieces / mm ² , the number of precipitates is small, so that an unetched portion is likely to occur, and a large number of coarse pits are formed. If the number of precipitates exceeds 100,000 pieces / mm ² , the number of precipitates As a result, it becomes difficult to form uniform pits, and it becomes difficult to obtain an aluminum alloy plate suitable as a support for lithographic printing.

  In the present invention, by setting the amount of Fe solid solution to 20 to 100 ppm, the burning strength can be maintained and uniform etch pits can be formed by electrolytic treatment. If the Fe solid solution amount is less than 20 ppm, the burning strength is likely to decrease. If the Fe solid solution amount exceeds 100 ppm, the electrolytic surface roughening property decreases, and the pit pattern becomes uneven, making it suitable as a support for lithographic printing plates. It becomes difficult to obtain an aluminum alloy plate.

  Further, a part or all of the constituent elements of the aluminum alloy plate constituting the present invention form an intermetallic compound, and the amount of Fe forming the intermetallic compound is 50 to 99.8% of the total amount of Fe, The amount of Si forming the intermetallic compound is 5 to 40% of the total amount of Si, and the Al—Fe—Si based intermetallic compound with respect to the amount of Fe (A%) forming the Al—Fe based intermetallic compound is By setting the ratio (B% / A%) of the amount of Fe (B%) formed to 0.9 or less, more uniform pits can be formed in the electrolytic treatment.

  If the amount of Fe forming the intermetallic compound is less than 50% of the total amount of Fe, the intermetallic compound as the starting point of the pit cannot be sufficiently obtained, so that coarse pits are likely to be formed, and the intermetallic compound is formed. If the amount of Fe exceeds 99.8% of the total amount of Fe, it is difficult to obtain a uniform pit pattern because an intermetallic compound is excessively formed. If the amount of Si forming the intermetallic compound is less than 5% of the total amount of Si, the amount of solid solution of Si increases, the potential difference between the matrix and the intermetallic compound decreases, and the electrochemical solubility decreases. Also, a large amount of simple substance Si is deposited, and ink stains are likely to occur. When the amount of Si forming the intermetallic compound exceeds 40% of the total amount of Si, it becomes difficult to obtain a uniform pit pattern because the intermetallic compound is excessively formed.

  The Al—Fe-based intermetallic compound has higher electrochemical solubility than the Al—Fe—Si-based intermetallic compound, and has a strong effect as a starting point of pits. The ratio (B% / A%) of the Fe amount (B%) forming the Al-Fe-Si intermetallic compound to the Fe amount (A%) forming the Al-Fe based intermetallic compound is 0. If it is larger than .9, the generation efficiency of pits is reduced and coarse pits are likely to be generated.

Furthermore, in the present invention, by adjusting the number of oil pits having a diameter (equivalent circle diameter) of 30 μm or more to 50 pieces / mm ² or less on the surface of the aluminum alloy plate after the final cold rolling, the electrolytic rough surface Etching pits formed in the crystallization process can be made more uniform. Since the aluminum alloy of the present invention contains Mg, large oil pits having a diameter of 30 μm or more tend to remain as coarse pits even after electrolytic graining. When such coarse pits exceed 50 pieces / mm ² , Etching pits formed by the electrolytic surface roughening treatment tend to be non-uniform.

In order to adjust the number of oil pits having a diameter (equivalent circle diameter) of 30 μm or more to 50 / mm ² or less, the final cold rolling degree, the form of the rolling roll surface, the properties of the rolling oil, the supply of the rolling oil It is necessary to adjust the amount. In the case of an aluminum alloy containing Mg and having a relatively large deformation resistance as in the present invention, a roll having a roll surface roughness of arithmetic average roughness Ra: 0.2 to 0.5 μm in the final cold rolling. It is desirable to perform cold rolling using a rolling oil having a viscosity of 1 to 6 cSt.

  When the roll surface roughness exceeds the arithmetic average roughness Ra of 0.5 μm, the local surface pressure within the contact arc length increases, the oil film is cut and the metal contact area is increased, and lubrication failure is likely to occur. . If Ra is less than 0.2 μm, the amount of rolling oil introduced between the rolling roll and the rolled material becomes excessive, and the number of large oil pits increases. If the viscosity of the rolling oil is less than 1 cSt, the amount of rolling oil introduced between the rolling roll and the rolled material is reduced, and lubrication is likely to occur. If the viscosity exceeds 6 cSt, the rolling oil is introduced between the rolling roll and the rolled material. The amount of rolling oil becomes excessive and the number of large oil pits increases.

  As the rolling oil in the final cold rolling, it is preferable to use a rolling oil in which the relationship between the Mg content (Mg%) in the aluminum alloy sheet and the viscosity ρ of the rolling oil satisfies ρ ≦ 2 × Mg + 4. . When ρ> (2 × Mg + 4), the deformation resistance is small, and the amount of rolling oil introduced between the rolling roll and the rolled material increases, so that coarse pits are easily formed excessively.

  In the present invention, by further specifying the crystal grain size as viewed from the plate surface, it is possible to suppress the appearance defects after electrolytic graining such as uneven surface quality and streak. That is, the average crystal grain length in the direction orthogonal to the rolling direction viewed from the plate surface is 100 μm or less, and the average crystal grain length in the direction parallel to the rolling direction viewed from the plate surface is the average crystal grain in the direction orthogonal to the rolling direction. 2 to 20 times the length. When the average crystal grain length in the direction perpendicular to the rolling direction as viewed from the plate surface exceeds 100 μm, surface quality unevenness occurs. If the average crystal grain length in the direction parallel to the rolling direction is less than twice the average crystal grain length in the direction perpendicular to the rolling direction, the strength becomes insufficient as a support for a printing plate, and if it exceeds 20 times, streak occurs.

  The production of an aluminum alloy plate for a lithographic printing plate according to the present invention is performed by ingot-making the aluminum alloy ingot by continuous casting or the like, and homogenizing the obtained ingot, followed by hot rolling and cold rolling. Done.

  The rolled surface of the ingot is preferably chamfered by 3 to 15 mm on one side. If it is less than 3 mm / single side, coarse crystal grains (coarse crystals) in the vicinity of the ingot surface layer are difficult to remove, and the chamfered surface has a non-uniform structure, which causes streak. If the amount of chamfering exceeds 15 mm / single side, the yield decreases, which is uneconomical.

Ingot homogenization treatment for producing the aluminum alloy plate in which precipitates having a diameter (equivalent circle diameter) of 0.1 to 1.0 μm are dispersed on the surface of the plate at 10,000 to 100,000 pieces / mm ^2. A preferred embodiment from the end of hot rolling to the end of hot rolling is as follows.

  The temperature rising rate of the ingot during the homogenization treatment is preferably 20 to 60 ° C./hr, and effectively acts to obtain the predetermined precipitate distribution. If it is less than 20 ° C./hr, the precipitation proceeds, the precipitate is likely to grow to a size exceeding 1 μm in diameter, and the number of precipitates is reduced. At a temperature increase rate exceeding 60 ° C./hr, heating is too fast and precipitation does not proceed, making it difficult to obtain a predetermined precipitate.

  The homogenization treatment is preferably carried out under the condition that the temperature is maintained at 450 to 580 ° C. for 1 hour or longer. By this homogenization treatment, Fe and Si dissolved in supersaturation are uniformly deposited and formed during the electrolytic treatment. Etching pits become fine circles and printing durability is improved. When the homogenization treatment temperature is less than 450 ° C., the precipitation of Fe and Si that is the starting point of pit generation is not sufficient, and unetched portions are formed during the electrolytic treatment, and the pit pattern tends to be non-uniform. When the homogenization treatment is performed at a temperature exceeding 580 ° C., the amount of Fe dissolved increases, and as a result, fine precipitates that are the starting point of pit generation decrease. If the holding time of the homogenization treatment is less than 1 hr, the precipitation of Fe and Si becomes insufficient and the pit pattern becomes non-uniform.

  Hot rolling is preferably started at a temperature of 400 ° C to 520 ° C. When the temperature is lower than 400 ° C., the precipitation of Fe and Si that is the starting point of pit generation is not sufficient, and an unetched portion is formed during the electrolytic treatment, and the pit pattern tends to be nonuniform. In addition, since the deformation resistance is large, it is not possible to increase the degree of processing per process, and the number of rolling passes increases, which is not economical. When hot rolling is started at a temperature exceeding 520 ° C., coarse recrystallized grains are generated during hot rolling, and streaks due to streak-like non-uniform structures tend to occur.

  The end temperature of hot rolling is preferably 320 to 400 ° C. Below 320 ° C., recrystallization occurs only partially, and the non-recrystallized portion causes streaks. In addition, since the amount of strain accumulation after the final cold rolling increases, the recrystallization temperature decreases and the burning strength decreases. If the temperature exceeds 400 ° C., recrystallization occurs on the entire surface, but becomes coarse and causes streak. The plate thickness at the end of hot rolling is preferably 5 mm or less. If it is 5 mm or more, the reduction ratio during hot rolling is insufficient and the amount of strain introduced is reduced, so that the recrystallized grains are likely to be coarsened.

  Preferred embodiments from the ingot homogenization treatment to the end of hot rolling for producing the above aluminum alloy sheet in which the solid solution amount of Fe is 20 to 100 ppm are as follows.

  The temperature rising rate of the ingot during the homogenization treatment is preferably 20 to 60 ° C./hr, and acts effectively to obtain the predetermined solid solution state. If it is less than 20 ° C./hr, the amount of precipitation increases, the amount of solid solution decreases greatly, and it takes time for heating, which is not economical. At a rate of temperature increase exceeding 60 ° C./hr, heating is too fast and precipitation does not proceed, making it difficult to obtain a predetermined solid solution state.

  The homogenization treatment is preferably carried out under the condition that the temperature is maintained at 450 to 580 ° C. for 1 hour or longer. By this homogenization treatment, the amount of Fe and Si dissolved in supersaturation is adjusted, and electrolysis is performed. Etching pits formed at the time of processing become a fine circle, and printing durability is improved. If the homogenization temperature is less than 450 ° C., the precipitation of Fe and Si, that is, the decrease in the amount of solid solution is not sufficient, and therefore the pit pattern tends to be non-uniform. When the homogenization process is performed at a temperature exceeding 580 ° C., the amount of solid solution of Fe increases excessively, so that the pit pattern becomes non-uniform. If the holding time of the homogenization treatment is less than 1 hr, the solid solution state of Fe and Si in the longitudinal direction and the width direction becomes non-uniform and the pit pattern becomes non-uniform.

  After the homogenization treatment, the temperature is once lowered to room temperature, whereby the precipitation of Fe and Si can be controlled to obtain a target solid solution state.

Hot rolling is preferably started at a temperature of 350 to 500 ° C. If it is less than 350 ° C., since the deformation resistance is large, the degree of work per one time cannot be increased, and the number of rolling passes increases, which is not economical. When hot rolling is started at a temperature exceeding 500 ° C., coarse recrystallized grains are generated during hot rolling, and streaks due to streak-like non-uniform structures tend to occur.

  The end temperature of hot rolling is preferably 300 to 380 ° C. Below 300 ° C., recrystallization occurs only partially, and the non-recrystallized portion causes streak. In addition, since the amount of strain accumulation after the final cold rolling increases, the recrystallization temperature decreases and the burning strength decreases. When the temperature exceeds 380 ° C., recrystallization occurs on the entire surface, but becomes coarse and causes streak. The plate thickness at the end of hot rolling is preferably 5 mm or less. If it is 5 mm or more, the reduction ratio during hot rolling is insufficient and the amount of strain introduced is reduced, so that the recrystallized grains are likely to be coarsened.

  Part or all of the component elements form an intermetallic compound, the amount of Fe forming the intermetallic compound is 50 to 99.8% of the total amount of Fe, and the amount of Si forming the intermetallic compound is The amount of Fe (B%) forming the Al—Fe—Si intermetallic compound with respect to the amount of Fe (A%) forming the Al—Fe intermetallic compound in 5 to 40% of the total Si amount. Preferred embodiments from the ingot homogenization process to the end of hot rolling for producing the aluminum alloy sheet having a ratio (B% / A%) of 0.9 or less are as follows.

  The homogenization treatment is preferably performed under the condition that the temperature is maintained at 450 to 580 ° C. for 3 hours or more. By this homogenization treatment, Fe and Si that are dissolved in supersaturation are uniformly deposited, so that during the electrolytic treatment. The formed etching pit becomes a fine circle, and the printing durability is improved. If the homogenization temperature is less than 450 ° C., the precipitation of Al—Fe—Si intermetallic compound, which has a weak action as the starting point of pits, proceeds, so that the generation efficiency of pits decreases and coarse pits are generated, resulting in a pit pattern Tends to be non-uniform. When the homogenization treatment is performed at a temperature exceeding 580 ° C., the amount of Fe dissolved increases, and as a result, precipitation of Al—Fe-based intermetallic compounds having a strong effect as a starting point of pits decreases. If the holding time of the homogenization treatment is less than 3 hr, the precipitation of Fe and Si becomes insufficient and the pit pattern becomes non-uniform.

  It is preferable that the hot rolling is started at a temperature of 400 to 500 ° C. after the homogenization treatment, the temperature is lowered at a temperature lowering rate of 20 to 60 ° C./hr to the hot rolling start temperature. Precipitation proceeds during the temperature drop after homogenization. In particular, when the temperature is lowered to 400 to 450 ° C., precipitation of Si as well as Fe proceeds. When the temperature lowering rate is less than 20 ° C./hr, precipitation of the Al—Fe—Si intermetallic compound proceeds, so that the amount of precipitation increases, and the precipitation further progresses so that the precipitate grows to a size exceeding 1 μm in diameter. The number of precipitates decreases. Furthermore, since it takes time to heat, it is not economical. When the rate of temperature drop exceeds 60 ° C./hr, the time for the progress of precipitation is not sufficient, and the temperature of the ingot becomes non-uniform depending on the location, resulting in non-uniform precipitation of Fe and Si. Thus, recrystallization during the subsequent hot rolling is uneven depending on the location, and streaks are likely to occur.

  Hot rolling is preferably started at a temperature of 400 to 500 ° C. If it is less than 400 ° C., the deformation resistance is large, so the degree of processing per one time cannot be increased, and the number of rolling passes increases, which is not economical. When hot rolling is started at a temperature exceeding 500 ° C., coarse recrystallized grains are generated during hot rolling, and streaks due to streak-like non-uniform structures tend to occur.

  The end temperature of hot rolling is preferably 300 to 400 ° C. Below 300 ° C., recrystallization occurs only partially, and the non-recrystallized portion causes streak. In addition, since the amount of strain accumulation after the final cold rolling increases, the recrystallization temperature decreases and the burning strength decreases. If the temperature exceeds 400 ° C., recrystallization occurs on the entire surface, but becomes coarse and causes uneven patterns and streaks. The plate thickness at the end of hot rolling is preferably 5 mm or less. If it is 5 mm or more, the reduction ratio during hot rolling is insufficient and the amount of strain introduced is reduced, so that the recrystallized grains are likely to be coarsened.

  Any of the aluminum alloy sheets that have been hot-rolled as described above are cold-rolled without intermediate annealing. Cold rolling after hot rolling gives strength to prevent gripping when the support is wound around a plate cylinder when the aluminum alloy plate is applied as a support for lithographic printing, and during hot rolling or This is performed in order to adjust the length of the crystal grains generated immediately after hot rolling in the direction parallel to the rolling direction. The preferable degree of rolling work is in the range of 50 to 98%, and if it is less than 50%, it is difficult to give sufficient strength to prevent the gripping when it is wound around the plate cylinder, and if it exceeds 98%, hot rolling is performed. The crystal grains generated later extend too long in the direction parallel to the rolling direction, and streaks are likely to occur. In addition, after cold rolling, finish cold rolling is performed using a rolling roll having a special pattern engraved on the surface. For example, arithmetic average roughness Ra: 0.15 to 0.30 μm, unevenness in the direction perpendicular to the rolling direction An aluminum alloy plate having an average length RSm of 50 μm or less, a maximum valley depth Rv of 1 μm or less, and a maximum height Rz of 1.5 to 2.5 μm can also be used.

  Depending on the combination of the above composition and manufacturing process, the amount of aluminum powder on the plate surface, the distribution of precipitates, the amount of Fe solid solution, the amount of intermetallic compound and Fe, the amount of Si, the oil pit distribution, and the specified crystal A grain length is obtained and a strength characteristic is achieved in which the 0.2% proof stress after heat treatment at 270 ° C. for 7 minutes is 120 MPa or more. This strength characteristic is important as a printing plate support, and if it is less than 120 MPa, the fixed portion of the plate is likely to be deformed or damaged during printing, which causes printing misalignment.

  Examples of the present invention will be described below in comparison with comparative examples to demonstrate the effects of the present invention. These examples show one preferred embodiment of the present invention, and the present invention is not limited thereto.

Example 1 and Comparative Example 1
As an aluminum alloy for a test material, an aluminum alloy having the composition shown in Table 1 was melted and cast. The rolled surface of the resulting ingot is chamfered by 5 mm / single side to a thickness of 500 mm, the ingot is heated to a temperature of 530 ° C. at a temperature increase rate of 35 ° C./hr, and this temperature is maintained for 3.5 hours. The homogenization process was performed.

  Next, the temperature was lowered from the homogenization temperature of 530 ° C. to a hot rolling start temperature of 515 ° C. at a temperature lowering rate of 35 ° C./hr, hot rolled to a plate thickness of 3 mm, and hot rolling was completed at a temperature of 346 ° C. . After hot rolling, cold rolling was performed without intermediate annealing, and the plate thickness was set to 0.3 mm. In addition, the surface roughness of the roll used in cold rolling was arithmetic average roughness Ra: 0.3 μm, and the viscosity of the rolling oil was 3 cSt. In Table 1, those outside the conditions of the present invention are underlined. The relational expression between the Mg content and the Zn content, (4 × Zn% −1.4%) ≦ Mg% ≦ (4 × Zn% + 0.6%) is satisfied. did.

  About the obtained aluminum alloy plate (test material), the amount of aluminum powder on the plate surface after cold rolling, the number of precipitates having a diameter of 0.1 to 1.0 μm, and the plate surface diameter of 30 μm or more are obtained by the following method. The number of oil pits and the crystal grain length were measured. The results are shown in Table 2. Moreover, the burning resistance was evaluated, and the presence or absence of rubbing flaws generated in the coil wound up after the cold rolling was observed. The results are shown in Table 3. In Table 2, the crystal length is the crystal grain length (GL) in the direction parallel to the rolling direction as viewed from the plate surface, the crystal width is the crystal grain length (GT) in the direction orthogonal to the rolling direction, and the ratio is The ratio (GL / GT) is shown. Moreover, the thing under the conditions of this invention was underlined.

  Measurement of the amount of aluminum powder: As a quantitative analysis of residual abrasion powder on the plate surface, a certain area of the plate surface was wiped off with absorbent cotton soaked in a solvent, and the aluminum content in the absorbent cotton was measured. The wiping method is shown in FIG.

  Measurement of the number of precipitates having a diameter (equivalent circle diameter) of 0.1 to 1.0 μm: After degreasing and cleaning the surface of the aluminum alloy plate, etching is performed for 10 seconds with an aqueous solution (Keller solution) mixed with nitric acid, hydrofluoric acid and hydrochloric acid. The photograph magnified 1000 times with an optical microscope was taken, and the particle size distribution of the precipitates was measured using an image analyzer (Lusex 500 manufactured by Nireco Corporation). In this case, the diameter of the precipitate was converted as the equivalent circle diameter, that is, the diameter of a circle having the same area as the area of the precipitate in the photograph, and the distribution density of the intermetallic compound was determined from this result.

  Measurement of the number of oil pits: After degreasing and cleaning the surface of the aluminum alloy plate, the surface was observed at a magnification of 500 times using a scanning electron microscope (SEM), and the number and distribution of oil pits were measured by a cutting method.

  Measurement of crystal grain length: After degreasing and cleaning the surface of the aluminum alloy plate, mirror polishing, anodizing with Parker's solution, observing crystal grains in the polarization mode of an optical microscope, direction perpendicular or parallel to the rolling direction The crystal grain length was determined by a cutting method.

  Burning resistance evaluation: As an index of heat resistance softening resistance, for convenience, the aluminum plate was heated for 7 minutes in an atmospheric furnace maintained at 270 ° C. and then subjected to a tensile test to measure 0.2% proof stress. The burning resistance of was evaluated. The proof stress was measured in the direction parallel to the rolling direction of the aluminum alloy sheet (L direction), and the 0.2% proof stress after heating at 270 ° C. for 7 minutes passed 120 MPa or more (O), and less than 120 MPa was not acceptable. Passed.

  Observation of presence / absence of rubbing flaws in the coil: Evaluation was made on the case where rubbing wrinkles were visually observed on a plate surface of a certain area as bad (x) and those where no flaws were observed as good (◯).

Further, the obtained aluminum alloy plate was degreased (solution: 5% sodium hydroxide, temperature: 60 ° C., time: 10 seconds) -neutralization treatment (solution: 10% nitric acid, temperature: 20 ° C., time: 30 seconds). ) -AC electrolytic surface roughening treatment (solution: 2.0% hydrochloric acid, temperature: 25 ° C., frequency: 50 Hz, current density: 60 A / dm ² , time: 20 seconds) —desmut treatment (solution: 5% sodium hydroxide) , Temperature: 60 ° C., time: 5 seconds) -anodic oxidation treatment (solution: 30% sulfuric acid-temperature: 20 ° C., time: 60 seconds), washed with water, dried, cut into a certain size and used as a test material .

Each test material was observed for the presence of uneven patterns and streaks. In addition, using a scanning electron microscope (SEM), the surface was observed at a magnification of 500 times, and a photograph was taken so that the area of the visual field was 0.04 mm ^2. The uniformity of pits was evaluated. The results are shown in Table 3.

Observation of the presence or absence of uneven patterns: If a strong uneven pattern is visually observed on the surface of the test material, it is defective (X), if only a weak uneven pattern is observed is good (○), and if no uneven pattern is observed, it is excellent (◎ ).
Observation of the presence or absence of streak: Evaluation was made on the surface of the test material where streak was visually observed as defective (x) and when no streak was observed as good (◯).

Evaluation of generation of unetched portion: Unetched portion exceeding 20% was judged as bad (x), 15-20% was good (◯), and less than 15% was judged excellent (◎).
Evaluation of uniformity of etch pits: Large pits with an equivalent circle diameter exceeding 10 μm are defective (×) when the area ratio exceeds 10% of all pits (×), 5-10% are good (◯), 5 Less than% is excellent (◎) and less than 20% is good (良好).

  As can be seen in Table 3, the test material No. 1-No. No. 5 shows no burning flaws, excellent burning resistance, no uneven pattern or streak, excellent etching after electrolytic treatment, and uniform etching pits formed on the entire surface. It had been.

  In contrast, test material No. No. 6 was inferior in burning resistance because of its low Mg content, increased in the amount of aluminum powder, resulting in non-uniform pit formation, and poor appearance due to unetched portions and uneven patterns after electrolytic graining. On the other hand, the test material No. In No. 7, since the Mg content was large, the uniformity of the pits was inferior, the amount of aluminum powder was reduced, and scratches were generated in the coil. Test material No. No. 8 had a large Zn content, and the surface roughness was uneven. Test material No. 9 has a small content of Fe and Si, so the number of precipitates is small, the distribution of Al-Fe-based intermetallic compounds and Al-Fe-Si-based intermetallic compounds is uneven, and pit formation is uneven. . Moreover, since there was little content of Fe, the amount of precipitation and the amount of solid solution also decreased, and the burning proof stress became inadequate. On the other hand, the test material No. Since No. 10 had a large content of Fe and Si, the number of precipitates was large, a coarse compound was generated, and the uniformity of the roughened structure was lowered. Test material No. No. 11 had a high Cu content, and the pits during the electrolytic treatment were coarse, resulting in an unetched portion and non-uniformity. Test material No. No. 12 had a large Ti content, and an Al—Ti coarse compound was produced, resulting in a non-uniform roughened structure. Test material No. No. 13 had a high Mn content, and a coarse Al—Fe—Mn or Al—Fe—Mn—Si intermetallic compound was produced, resulting in uneven surface roughness during the electrolytic treatment. Test material No. In No. 14, the total amount of Pb, In, Sn, and Ga exceeded 0.05%, so the shape of the pits collapsed and became non-uniform.

Example 2 and Comparative Example 2
The surface milling, homogenization, and hot rolling of the ingot of the aluminum alloy A cast in Example 1 were performed under the conditions shown in Table 4, and after hot rolling, the intermediate annealing was not performed in Table 4. Cold rolling was performed to the plate thickness shown. Table 5 shows the surface roughness of the roll used in the cold rolling and the viscosity of the rolling oil. In Tables 4 and 5, those outside the conditions of the present invention are underlined.

  About the obtained aluminum alloy plate (test material), the amount of aluminum powder on the plate surface after cold rolling, the number of precipitates having a diameter of 0.1 to 1.0 μm, and the diameter of the plate surface of 30 μm or more are obtained by the above-described method. The number of oil pits and the crystal grain length were measured. The results are shown in Table 5. Also, the burning resistance was evaluated by the above-described method, and the etching property was evaluated by observing the presence or absence of rubbing flaws generated in the coil wound after cold rolling, the presence of uneven patterns, and streak. The results are shown in Table 6.

  As shown in Table 6, the test material No. In both Nos. 15 and 16, generation of rubbing flaws was observed, burning resistance was excellent, uneven patterns and streaks were not generated, etching property after electrolytic treatment was excellent, and uniform etching pits were formed on the entire surface. Was formed. In contrast, test material No. In No. 17, streaks occurred because the amount of chamfering was small. Test material No. No. 18 has a slow heating rate of the ingot at the time of homogenization, so that the precipitates grow to a size exceeding 1 μm in diameter, the number of precipitates decreases, unetched portions are formed, and pits are not uniform. Moreover, since the precipitation amount became excessive, the Fe solid solution amount was insufficient, and the burning strength was lowered. On the other hand, test material No. No. 19 has a high temperature rise rate of the ingot at the time of the homogenization treatment, so that the precipitation does not proceed sufficiently and the starting point of the pit is insufficient, so that an unetched part is formed during the electrolytic treatment and the uniformity of the pit is impaired. It is. Test material No. In No. 20, since the homogenization temperature was low, the precipitation of Fe and Si as starting points of pit generation was not sufficient, and an unetched part was formed during the electrolytic treatment and the pit pattern became non-uniform. Test material No. In No. 21, since the homogenization temperature is high, the solid solution amount of Fe is increased, resulting in a decrease in fine precipitates that are the starting point of pit generation, and formation of unetched portions and non-uniform pit patterns. Became. Test material No. No. 22 has a short holding time of the homogenization treatment, so that Fe and Si are not sufficiently precipitated, an unetched portion is formed, and the pit pattern becomes non-uniform. Test material No. No. 23 had a low hot rolling start temperature, resulting in a low hot rolling end temperature, recrystallization occurring only partially, and streak. In addition, since the strain accumulation after the final cold rolling increased, the recrystallization temperature decreased and the burning strength also decreased. Test material No. In No. 24, since the hot rolling start temperature was high and the hot rolling end temperature was also high, recrystallization occurred on the entire surface but became coarse, resulting in surface quality unevenness and streak. Test material No. In No. 25, since the plate thickness at the end of hot rolling was thick, the reduction rate during hot rolling was insufficient, and the amount of strain introduced was reduced, so that the recrystallized grains became coarse and surface quality unevenness occurred. Test material No. 26, the arithmetic mean roughness of the roll surface is small, the amount of rolling oil introduced between the rolling roll and the rolled material becomes excessive, the number of large oil pits increases, and etching formed by electrolytic surface roughening treatment The pits became uneven. Also, the amount of powder was reduced, and rubbing wrinkles occurred. Test material No. No. 27 has a rough arithmetic average roughness of the roll surface, and the amount of rolling oil introduced between the rolling roll and the rolled material is reduced, resulting in poor lubrication, resulting in an increase in the amount of powder and uneven pit formation. As a result, appearance defects due to unetched portions and uneven patterns occurred after electrolytic graining. Test material No. No. 28, because the rolling oil has a low viscosity, the amount of rolling oil introduced between the rolling roll and the rolled material is reduced, resulting in poor lubrication, resulting in an increase in the amount of aluminum powder and uneven pit formation. After electrolytic graining, appearance defects due to unetched parts and uneven patterns occurred. Test material No. No. 29, because the viscosity of the rolling oil is high, the amount of rolling oil introduced between the rolling roll and the rolled material becomes excessive, increasing the number of large oil pits, and there are etching pits formed by the electrolytic surface roughening treatment. It became uneven. In addition, the amount of aluminum powder was reduced, and scratches were generated in the coil.

Example 3 and Comparative Example 3
The rolled surface of the ingot of the aluminum alloy cast in Example 1 (Table 1) is chamfered by 5 mm / one side to a thickness of 500 mm, and the ingot is heated to a temperature of 530 ° C. at a temperature increase rate of 35 ° C./hr. Then, the mixture was homogenized by maintaining at this temperature for 3.5 hours, and then cooled to room temperature.

  Subsequently, it heated to hot-rolling start temperature 469 degreeC, hot-rolled to plate | board thickness 3mm, and finished hot rolling at the temperature of 353 degreeC. After hot rolling, cold rolling was performed without intermediate annealing, and the plate thickness was set to 0.3 mm. In addition, the surface roughness of the roll used in cold rolling was arithmetic average roughness Ra: 0.3 μm, and the viscosity of the rolling oil was 3 cSt.

  With respect to the obtained aluminum alloy plate (test material), the amount of aluminum powder on the surface of the plate after cold rolling, the number of precipitates having a diameter of 0.1 to 1.0 μm, and an oil having a diameter of 30 μm or more on the surface of the plate was obtained by the above-described method. The number of pits and the crystal grain length were measured. Further, the amount of Fe solid solution was measured by the following method. The results are shown in Table 7. Also, the burning resistance was evaluated by the above-described method, and the etching property was evaluated by observing the presence or absence of rubbing flaws generated in the coil wound after cold rolling, the presence of uneven patterns, and streak. The results are shown in Table 8. In Table 7, those outside the conditions of the present invention are underlined.

  Measurement of Fe solid solution amount: An aluminum alloy plate was dissolved in hot phenol, and the amount of Fe in the filtrate was quantified. The details were in accordance with “Measurement of solid solution amount by wet chemical analysis” described in “Light Metals Vol. 50 (2000) pp. 518-526”.

  As shown in Table 8, the test material No. 30-No. In each of the samples 34, no generation of rubbing flaws was observed, burning resistance was excellent, uneven patterns and streaks were not generated, etching property after electrolytic treatment was excellent, and uniform etching pits were formed on the entire surface. It had been. In contrast, test material No. No. 35 had poor burning proof strength due to low Mg content, and increased the amount of aluminum powder, resulting in non-uniform pit formation, resulting in poor appearance due to unetched portions and uneven patterns after electrolytic graining. On the other hand, the test material No. No. 36 was inferior in pit uniformity due to its high Mg content, and the amount of aluminum powder was reduced, resulting in scratches in the coil. Test material No. No. 37 had a large Zn content, and the surface roughness was uneven. Test material No. 38 has a low Fe and Si content, so the number of precipitates is small, the distribution of Al-Fe-based intermetallic compounds and Al-Fe-Si-based intermetallic compounds becomes uneven, unetched portions are formed, and pits are formed. Formation was uneven. Moreover, since the amount of solid solution of Fe is also small, the burning strength is inferior. On the other hand, the test material No. Since No. 39 has a large content of Fe and Si, the number of precipitates was large, a coarse compound was generated, and the uniformity of the roughened structure was lowered. Further, since the amount of Fe solid solution was large, the pit pattern was not uniform. Test material No. No. 40 had a large Cu content, and an unetched portion was formed during the electrolytic treatment, resulting in coarse and non-uniform pits. Test material No. No. 41 had a large Ti content, and an Al—Ti coarse compound was produced, resulting in a non-uniform roughened structure. Test material No. No. 42 had a high Mn content, and a coarse Al—Fe—Mn or Al—Fe—Mn—Si based intermetallic compound was produced, resulting in uneven surface roughness during electrolytic treatment. Test material No. In No. 43, since the total amount of Pb, In, Sn and Ga exceeded 0.05%, the shape of the pits collapsed and became non-uniform.

Example 4 and Comparative Example 4
The surface of the aluminum alloy B ingot cast in Example 1 was chamfered, homogenized, and hot-rolled under the conditions shown in Table 9, and after hot rolling, the intermediate annealing was not performed. Cold rolling was performed to the plate thickness shown. The ingot was homogenized, cooled to room temperature, and heated to the hot rolling start temperature. Table 10 shows the surface roughness of the roll used in the cold rolling and the viscosity of the rolling oil. In Tables 9 and 10, those outside the conditions of the present invention are underlined.

  About the obtained aluminum alloy plate (test material), the amount of aluminum powder on the plate surface after cold rolling, the number of precipitates having a diameter of 0.1 to 1.0 μm, the amount of Fe solid solution, The number of oil pits having a diameter of 30 μm or more and the crystal grain length were measured. The results are shown in Table 10. Also, the burning resistance was evaluated by the above-described method, and the etching property was evaluated by observing the presence or absence of rubbing flaws generated in the coil wound after cold rolling, the presence of uneven patterns, and streak. The results are shown in Table 11.

  As shown in Table 11, the test material No. Neither 44 nor 45 shows the occurrence of rubbing flaws, has excellent burning resistance, does not cause uneven patterns and streaks, has excellent etching properties after electrolytic treatment, and has uniform etching pits on the entire surface. Was formed. In contrast, test material No. No. 46, because the temperature rise rate of the ingot during the homogenization treatment is slow, the precipitates grow to a size exceeding 1 μm in diameter, the number of precipitates decreases, and unetched portions are formed, resulting in poor pit uniformity. . Moreover, since the precipitation amount became excessive, the Fe solid solution amount was insufficient, and the burning strength was lowered. Test material No. In No. 47, since the temperature of the ingot during the homogenization treatment was high, the precipitation was insufficient, and an unetched portion was formed during the electrolytic treatment and the pit pattern became non-uniform. Test material No. In No. 48, since the homogenization treatment temperature was low, the precipitation of Fe and Si, that is, the decrease in the amount of solid solution was not sufficient, so that an unetched portion was formed during the electrolytic treatment and the pit pattern became non-uniform. Test material No. 49, since the homogenization temperature is high, the amount of solid solution of Fe becomes excessive, resulting in a decrease in fine precipitates that are the starting point of pit generation, the formation of unetched portions and the formation of pit patterns. It became uneven. Test material No. In No. 50, since the homogenization time was short, the solid solution state of Fe and Si in the longitudinal direction and the width direction became non-uniform, and the pit pattern became non-uniform.

Example 5, Comparative Example 5
The rolled surface of the ingot of the aluminum alloy cast in Example 1 (Table 1) is chamfered by 5 mm / one side to a thickness of 500 mm, and the ingot is heated to a temperature of 530 ° C. at a temperature increase rate of 35 ° C./hr. Then, a homogenization treatment was performed by maintaining this temperature for 3.5 hours.

  Next, the temperature was lowered to a hot rolling start temperature of 490 ° C. at a rate of 35 ° C./hr, hot rolled to a plate thickness of 3 mm, and hot rolling was terminated at a temperature of 346 ° C. After hot rolling, cold rolling was performed without intermediate annealing, and the plate thickness was set to 0.3 mm. In addition, the surface roughness of the roll used in cold rolling was arithmetic average roughness Ra: 0.3 μm, and the viscosity of the rolling oil was 3 cSt.

  About the obtained aluminum alloy plate (test material), the amount of aluminum powder on the plate surface after cold rolling, the number of precipitates having a diameter of 0.1 to 1.0 μm, the amount of Fe solid solution, The number of oil pits having a diameter of 30 μm or more and the crystal grain length were measured. In addition, by the following method, the ratio of the amount of Fe forming the intermetallic compound to the total amount of Fe (Fe as a compound) (%), the ratio of the amount of Si forming the intermetallic compound to the total amount of Si ( Ratio of Fe (B%) forming Al—Fe—Si intermetallic compound to Si (%) as compound, and Fe amount (A%) forming Al—Fe intermetallic compound (B% / A%) was determined. The results are shown in Table 12. Also, the burning resistance was evaluated by the above-described method, and the etching property was evaluated by observing the presence or absence of rubbing flaws generated in the coil wound after cold rolling, the presence of uneven patterns, and streak. The results are shown in Table 13. In Table 12, those outside the conditions of the present invention are underlined.

  Measurement of Fe amount and Si amount forming intermetallic compound: The amount of Fe and Si in the total intermetallic compound was examined by a phenol residue analysis method as shown in FIG. The ratio of Fe amount in Fe-Si intermetallic compound (wt%)) / (Fe amount in Al-Fe intermetallic compound (wt%)) was determined.

  As shown in Table 13, the test material No. 51-No. In all cases, no generation of rubbing flaws was observed, burning resistance was excellent, uneven pattern and streak were not generated, etching property after electrolytic treatment was excellent, and uniform etching pits were formed on the entire surface. It had been. In contrast, test material No. No. 56 was inferior in burning resistance because of its low Mg content, increased in the amount of aluminum powder, resulting in non-uniform pit formation, and poor appearance due to unetched portions and uneven patterns after electrolytic graining. On the other hand, the test material No. No. 57 was inferior in pit uniformity due to its high Mg content, and the amount of aluminum powder was reduced, resulting in scratches in the coil. Test material No. No. 58 had a large Zn content, and the surface roughness was uneven. Test material No. 59 has a low content of Fe and Si, so the number of precipitates is small, the distribution of Al-Fe-based intermetallic compounds and Al-Fe-Si-based intermetallic compounds becomes uneven, unetched portions are formed, and pits are formed. Formation was uneven. Moreover, since the amount of solid solution of Fe is also small, the burning strength is inferior. Furthermore, since the amount of Si forming the intermetallic compound exceeds 40% of the total amount of Si, the ratio of the Al—Fe—Si intermetallic compound having a weak action as the starting point of the pit is large. The generation efficiency decreased and coarse pits were generated, resulting in non-uniform pit patterns. (The ratio (B% / A%) of the Fe amount (B%) forming the Al—Fe—Si intermetallic compound to the Fe amount (A%) forming the Al—Fe based intermetallic compound is If the ratio is larger than 0.9, the generation efficiency of pits is reduced and coarse pits are likely to be formed, whereas test material No. 60 has a large content of Fe and Si, and thus has a large number of precipitates and is a coarse compound. In addition, the uniformity of the roughened structure was reduced, and the pit pattern was non-uniform because of the large amount of Fe solid solution. An unetched part was formed, and the pits were coarse and non-uniform.Test material No. 62 had a large Ti content, and an Al-Ti coarse compound was produced, resulting in a non-uniform surface structure. Test material No. 63 has a large Mn content and is coarse Al- An e-Mn-based or Al-Fe-Mn-Si-based intermetallic compound was formed, resulting in uneven surface roughness during the electrolytic treatment.Test material No. 64 is the total amount of Pb, In, Sn and Ga Was over 0.05%, the shape of the pits collapsed and became non-uniform.

Example 6 and Comparative Example 6
The chamfering, homogenization treatment, and hot rolling of the rolled surface of the ingot of the aluminum alloy C cast in Example 1 were performed under the conditions shown in Table 14, and after hot rolling, the intermediate annealing was not performed in Table 14. Cold rolling was performed to the plate thickness shown. The ingot was homogenized, cooled to room temperature, and heated to the hot rolling start temperature. Table 15 shows the surface roughness of the rolls used in the cold rolling and the viscosity of the rolling oil. In Tables 14 and 15, those that deviate from the conditions of the present invention are underlined.

  About the obtained aluminum alloy plate (test material), the amount of aluminum powder on the surface of the plate after cold rolling, the number of precipitates having a diameter of 0.1 to 1.0 μm, the amount of Fe solid solution, the total amount of Fe by the above method. Of the amount of Fe forming the intermetallic compound with respect to the ratio of the amount of Si forming the intermetallic compound with respect to the total amount of Si and the amount of Fe (A%) forming the Al—Fe intermetallic compound The ratio (B% / A%) of the Fe amount (B%) forming the Al—Fe—Si intermetallic compound (B% / A%), the number of oil pits with a diameter of 30 μm or more, the crystal grain length, and the intermetallic compound are formed. The ratio of the amount of Fe forming, the ratio of the amount of Si forming the intermetallic compound, and the amount of Fe forming the Al—Fe based intermetallic compound are forming the Al—Fe—Si based intermetallic compound. The ratio of Fe amount was measured. The results are shown in Table 15. Also, the burning resistance was evaluated by the above-described method, and the etching property was evaluated by observing the presence or absence of rubbing flaws generated in the coil wound after cold rolling, the presence of uneven patterns, and streak. The results are shown in Table 18.

  As shown in Table 16, test material No. In both Nos. 65 and 66, generation of rubbing flaws was not observed, burning resistance was excellent, uneven patterns and streaks were not generated, etching property after electrolytic treatment was excellent, and uniform etching pits were formed on the entire surface. Was formed. In contrast, test material No. In No. 67, since the homogenization temperature was low, the precipitation of Fe and Si as starting points of pit generation was not sufficient, and an unetched portion was formed during the electrolytic treatment and the pit pattern became non-uniform. Test material No. In No. 68, since the homogenization temperature is high, the amount of solid solution of Fe becomes excessive, and as a result, fine precipitates that are the starting point of pit generation are reduced, unetched portions are formed, and the pit pattern is not good. It became uniform. Test material No. In No. 69, since the homogenization time is short, the precipitation of Fe and Si becomes insufficient and the pit pattern becomes non-uniform. Test material No. 70, since the temperature drop rate of the ingot to the hot rolling start temperature after the homogenization treatment is slow, precipitation of the Al—Fe—Si intermetallic compound proceeds, and grows to a size exceeding 1 μm in diameter. The number of precipitates decreased, and the amount of Fe dissolved decreased. As a result, the burning resistance was insufficient and the pits were not uniform. Test material No. No. 71, since the temperature of the ingot to the hot rolling start temperature after the homogenization treatment is fast, the time for precipitation is not sufficient, and the temperature of the ingot is not uniform depending on the location. As a result, the precipitation of Si became non-uniform, and as a result, recrystallization during the subsequent hot rolling became non-uniform depending on the location, streaks occurred, and the pit pattern became non-uniform.

It is a flowchart of the wiping off method for measuring the amount of aluminum powder. It is a flowchart of the phenol residue analysis method for measuring the amount of Fe and Si in an intermetallic compound.

Claims (17)

Mg: 0.1 to 1.5% (mass%, the same applies hereinafter), Zn: 0.5% or lower (not including 0%, the same applies hereinafter), Fe: 0.1 to 0.6%, Si: 0 0.03 to 0.15%, Cu: 0.0001 to 0.1%, Ti: 0.0001 to 0.1%, an aluminum alloy plate having a composition composed of the balance aluminum and impurities. An aluminum alloy plate for a lithographic printing plate, wherein the amount of aluminum powder is adjusted to 0.1 to 3.0 mg / m ² . Mg: 0.1 to 1.5%, Zn: more than 0.05% and 0.5% or less, Fe: 0.1 to 0.6%, Si: 0.03 to 0.15%, Cu: 0 .0001-0.10%, Ti: 0.0001-0.05%, and the relationship between Mg content and Zn content is 4 × Zn% −1.4% ≦ Mg% ≦ 4 × Zn% A lithographic plate characterized in that the amount of aluminum powder on the surface of the plate is adjusted to 0.1 to 3.0 mg / m ² with an aluminum alloy plate having a composition consisting of the balance aluminum and impurities. Aluminum alloy plate for printing plates. The deposit of 10,000-100,000 pieces / mm < ² > disperse | distributes the diameter (equivalent circle diameter) 0.1-1.0 micrometer on the plate | board surface of the said aluminum alloy plate, The ^2nd aspect is characterized by the above-mentioned. Aluminum alloy plate for lithographic printing plates.   The aluminum alloy plate for a lithographic printing plate according to claim 2 or 3, wherein the solid solution amount of Fe in the aluminum alloy plate is 20 to 100 ppm.   Part or all of the constituent elements of the aluminum alloy plate form an intermetallic compound, and the amount of Fe forming the intermetallic compound is 50 to 99.8% of the total amount of Fe, forming an intermetallic compound. The amount of Fe forming the Al—Fe—Si intermetallic compound with respect to the amount of Fe (A%) forming the Al—Fe intermetallic compound when the Si amount is 5 to 40% of the total Si amount The aluminum alloy plate for lithographic printing plates according to any one of claims 2 to 4, wherein the ratio (B% / A%) of (B%) is 0.9 or less. The lithographic printing plate according to any one of claims 1 to 5, wherein the number of oil pits having a diameter (equivalent circle diameter) of 30 µm or more on the surface of the aluminum alloy plate is 50 pieces / mm ² or less. Aluminum alloy plate for use.   The aluminum alloy plate for lithographic printing plates according to any one of claims 1 to 6, wherein the aluminum alloy plate further contains Mn: more than 0.05% and not more than 0.3%.   The average crystal grain length in the direction perpendicular to the rolling direction as viewed from the plate surface of the aluminum alloy plate is 100 μm or less, and the average crystal grain length in the direction parallel to the rolling direction as seen from the plate surface is perpendicular to the rolling direction. The aluminum alloy plate for a lithographic printing plate according to any one of claims 1 to 7, wherein the average crystal grain length is 2 to 20 times.   The aluminum alloy plate further contains one or more elements selected from Pb, In, Sn and Ga in a total amount of 0.005 to 0.05%. The aluminum alloy plate for a lithographic printing plate as described in any one of 8 above.   The aluminum alloy plate for a lithographic printing plate according to any one of claims 3 to 9, wherein a 0.2% proof stress after heat treatment at 270 ° C for 7 minutes is 120 MPa or more.   An aluminum alloy having the composition according to any one of claims 2, 7, and 9 is ingoted, and the surface of the rolled surface of the obtained ingot is chamfered by 3 to 15 mm, and then the temperature is increased by 20 to 60 ° C / hr. A homogenization treatment is performed by heating to a temperature range of 450 to 580 ° C. at a speed and holding for 1 hour or more, then the start temperature is 400 to 520 ° C., the end temperature is 320 to 400 ° C., and the thickness at the end is 5 mm or less. A method for producing an aluminum alloy plate for a lithographic printing plate, comprising performing hot rolling and performing cold rolling without performing intermediate annealing.   An aluminum alloy having the composition according to any one of claims 2, 7, and 9 is ingoted, and the surface of the rolled surface of the obtained ingot is chamfered by 3 to 15 mm, and then the temperature is increased by 20 to 60 ° C / hr. Perform homogenization treatment by heating to a temperature range of 450 to 580 ° C at a speed and holding for 1 hour or more, then lower the temperature to room temperature, then heat to 350 to 500 ° C and start hot rolling and finish A method for producing an aluminum alloy plate for a lithographic printing plate, characterized by performing hot rolling at a temperature of 300 to 380 ° C., a thickness at the end of 5 mm or less, and cold rolling without performing intermediate annealing.   An aluminum alloy having the composition according to any one of claims 2, 7, and 9 is ingoted, and the surface of the rolled surface of the resulting ingot is chamfered by 3 to 15 mm, and then heated to a temperature range of 450 to 580 ° C. Then, a homogenization treatment is performed for 3 hours or more, the temperature is lowered from the holding temperature to the hot rolling start temperature at a temperature lowering rate of 20 to 60 ° C./hr, then the start temperature is 400 to 500 ° C., and the end temperature is 300 to 400. A method for producing an aluminum alloy plate for a lithographic printing plate, characterized in that hot rolling is performed at a temperature of 5 ° C. and the thickness at the end is 5 mm or less, and cold rolling is performed without performing intermediate annealing.   A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 1 or 2, wherein a rolling oil having a viscosity of 1 to 6 cSt is used in the final cold rolling. Production method.   A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 1 or 2, wherein the relationship between the Mg content (Mg%) and the viscosity ρ of the rolling oil used in the final cold rolling is -2x. A method for producing an aluminum alloy plate for a lithographic printing plate, wherein a rolling oil satisfying Mg% + 2 ≦ ρ ≦ −2 × Mg% + 8 is used in the final cold rolling.   A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 6, wherein the roll surface roughness is a roll having an arithmetic average roughness Ra of 0.2 to 0.5 µm in the final cold rolling, and the viscosity. A method for producing an aluminum alloy plate for a lithographic printing plate, comprising performing zero rolling using 1 to 6 cSt of rolling oil.   7. A method for producing an aluminum alloy plate for a lithographic printing plate according to claim 6, wherein the rolling oil satisfying ρ ≦ 2 × Mg + 4 is the final relationship between the Mg content (Mg%) and the viscosity ρ of the rolling oil. A method for producing an aluminum alloy plate for a lithographic printing plate, which is used in cold rolling.

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