JP5199042B2 - Aluminum alloy plate manufacturing equipment for lithographic printing plates - Google Patents

Description

  The present invention relates to an apparatus for producing an aluminum alloy plate for a lithographic printing plate. The present invention also relates to a method for producing an aluminum alloy plate for a lithographic printing plate using the apparatus for producing an aluminum alloy plate for a lithographic printing plate. The present invention also relates to an aluminum alloy plate for a lithographic printing plate obtained by the method for producing a lithographic printing plate support.

  A method for producing an aluminum alloy plate for a lithographic printing plate by a continuous casting method, that is, after melting an aluminum raw material and subjecting the resulting molten aluminum to a filtration treatment, the molten aluminum is supplied to a pair of cooling rollers via a molten metal supply nozzle A casting process, a cold rolling process, an intermediate annealing process, a finish cold rolling process, and a flatness correction for forming an aluminum alloy sheet by rolling while solidifying the molten aluminum with the pair of cooling rollers. The aluminum alloy plate for lithographic printing plates, which is made into an aluminum alloy plate having a thickness of 0.1 to 0.5 mm through the steps, has a simple process, so-called DC casting step, chamfering step, Less loss compared to the conventional method of manufacturing an aluminum alloy plate for lithographic printing plates consisting of a soaking process, a heating process, and a hot rolling process There are merits such as excellent process, less susceptible to process fluctuations, low initial equipment cost, low running cost, etc. It is said that it is difficult to apply to a material having a high surface quality requirement level such as a lithographic printing plate, and the applicants of the present application have made extensive studies so far to solve this problem.

When carrying out continuous casting, an aluminum alloy containing titanium and boron is added to the molten aluminum. TiB ₂ particles generated from an aluminum alloy containing titanium and boron added and melted in the molten aluminum act as a crystal structure refiner during casting. TiB ₂ particles are, by themselves, thin plate-like particles having a thickness of 1 to ₂ μm and a thickness of 0.1 to 0.5 μm. However, these particles easily form aggregates, and aggregates having a particle size of 100 μm or more (hereinafter, “ When TiB ₂ agglomerated particles ") are mixed into the cast plate, when the cast plate is rolled and / or tempered, and any one of them is finished into a thin plate, black strip-like failures are intermittently formed on the surface of the thin plate. This black stripe failure is sometimes referred to as black stripe failure.

  For example, as a method for preventing black stripe failure, the inventors of the present application have previously filtered a molten aluminum obtained by adding an aluminum alloy containing Ti and B to a patent document 1 using a filter tank. And the step of performing continuous casting and rolling, wherein the molten aluminum is a filter chamber in the filter tank, a single particle having a particle diameter of 10 μm or more formed of a compound of Ti and B present in an alloy containing Ti and B. A filter that prevents passage of agglomerates having a particle size of 10 μm or more formed by collecting one particle or a plurality of the compounds, and a filter rear chamber are sequentially passed, and the filter front chamber, the filter, and the filter rear chamber are heated by a heater. A method for producing a support for a lithographic printing plate characterized by being heated, wherein the filter is a collection of heat-resistant particles having a diameter of 5 mm or less. It is disclosed that the filter is a ceramic tube filter formed by sintering particles having heat resistance having a diameter of 0.5 to 2.0 mm.

  In addition, as a method for preventing black streak failure, the inventors of the present application previously supplied a molten metal from a molten metal supply nozzle to a casting and rolling means as a method for preventing a black streak failure, and the molten and cast metal is cast and rolled by the casting and rolling means. In the continuous casting and rolling apparatus for forming a cast plate, a recess is formed in a bottom surface of a flow path where the molten metal flows to the molten metal supply nozzle, and impurities contained in the molten metal are settled in the concave. The continuous casting and rolling apparatus, and the depth of the recess is 2 to 5 times the depth of the flow path, and the opening length in the flow direction of the recess is 1 to 10 times the depth of the flow path. The above-described continuous casting and rolling apparatus is disclosed.

Furthermore, the inventors of the present application, as a method of preventing the black streak failure by devising the recess, in Patent Document 3, a notch is formed on the bottom surface of the flow path of the molten aluminum at the front upper end with respect to the flow direction. Aluminum plate manufacturing method using continuous casting and rolling apparatus provided with concave portions, and aluminum plate manufacturing method using continuous casting and rolling apparatus provided with concave portions having notches also in the upper end portion behind the flow direction Is disclosed.
As a method for preventing the black streak failure by further devising the recess, the inventors of the present application supply a molten metal from the nozzle to the casting and rolling means and perform continuous casting and rolling by the casting and rolling means in Patent Document 4. Discloses a continuous casting and rolling apparatus in which a stirring means is provided in the recess, and the molten metal in the vicinity of the recess is stirred by the stirring means to prevent stagnation of the molten metal.

As described above, as a method for preventing the black streak failure, various proposals have been made for means for preventing the TiB ₂ aggregated particles that have settled and moved near the bottom of the molten metal from being mixed into the cast plate. ing.

Japanese Patent No. 3549080 JP 11-47892 A JP-A-11-254093 JP 2000-24762 A

However, even if such measures are taken to prevent the TiB ₂ agglomerated particles moving near the bottom of the molten metal from entering the cast plate, there is a problem that the continuous cast plate fails. The present invention has been made in view of such circumstances, and is intended for a lithographic printing plate capable of preventing the occurrence of a failure of a continuous cast plate due to causes other than mixing of TiB ₂ agglomerated particles moving near the bottom of the molten metal. It aims at providing the manufacturing apparatus of an aluminum alloy plate.

As a result of diligent study, the inventors of the present application have found that foreign substances existing on the surface layer of the molten metal, specifically, an oxide film existing on the surface layer of the molten metal and impurities existing in the oxide film (for example, mainly Al oxide). It has been found that mixing of impurities including Mg, Ti, etc.) into the cast plate causes failure of the continuous cast plate. Hereinafter, in the present specification, a failure of the continuous cast plate due to such a cause is referred to as a failure of the continuous cast plate (fault on the surface of the molten metal).
The present invention is based on the above knowledge, a molten metal supply nozzle having a molten metal flow path therein, a pair of cooling rollers to which the molten aluminum alloy is supplied from the molten supply nozzle, and an aluminum alloy in the molten metal supply nozzle An aluminum alloy plate continuous casting and rolling device provided with at least a container for supplying molten metal,
Means for trapping foreign matter existing on the surface layer of the molten aluminum alloy is provided upstream of the molten metal supply nozzle, and is a continuous casting and rolling apparatus for aluminum alloy sheets (hereinafter referred to as “continuous casting and rolling of the present invention”). Equipment ”).

In the first embodiment of the continuous casting and rolling apparatus of the present invention, so as to be located at the same height as the upper surface of the molten metal flow path near the upstream end of the molten metal supply nozzle, or above the upper surface, A baffle plate extending in a substantially horizontal direction from the upstream end face of the molten metal supply nozzle to the upstream side in the flow direction of the molten aluminum alloy and satisfying the following is provided, and the baffle plate is the trap means: To do.
Distance from the liquid surface of the molten aluminum alloy in the container to the lower surface of the baffle plate: 5 mm or more Length of the baffle plate in the flow direction of the molten aluminum alloy: 10 to 100 mm

  In 1st Embodiment of the continuous casting rolling apparatus of this invention, it is preferable that the thickness of the said baffle plate is 2-10 mm.

According to a second embodiment of the continuous casting and rolling apparatus of the present invention, the upstream end surface on the side including the upper surface of the molten metal flow path is more than the upstream end surface on the side including the lower surface of the molten metal flow path. Is also provided on the upstream side in the flow direction of the molten aluminum alloy, and provided with an extension that satisfies the following:
In the extension portion, a part of the upper surface of the molten metal channel protrudes downward so that the upper surface of the molten metal channel near the upstream end is lower than the upper surface of the remaining portion of the molten metal channel. And the convex part which satisfy | fills the following is provided, and this extension part is the said trap means, It is characterized by the above-mentioned.
Distance from the liquid surface of the molten aluminum alloy in the container to the upper surface of the molten metal flow path forming the convex portion: 10 to 200 mm
Length of the convex portion in the flow direction of the molten aluminum alloy: 5 to 100 mm
Difference in height between the upper surface of the molten metal flow path forming the convex portion and the upper surface of the remaining portion of the molten metal flow path: 5 to 100 mm
The distance between the downstream end portion of the convex portion in the flow direction of the molten aluminum alloy and the upstream end surface on the lower surface side of the molten metal flow path: 10 to 300 mm

In the second embodiment of the continuous casting and rolling apparatus of the present invention, the distance from the liquid surface of the molten aluminum alloy in the vessel to the upper surface of the molten metal flow path forming the convex portion is H ₁ , and the aluminum alloy in the vessel when the distance from the liquid surface of the molten metal to the bottom surface of the launder and H _2, it is preferable to satisfy the following.
0mm ≦ H ₁ − H ₂ ≦ 190mm

In the second embodiment of the continuous casting and rolling apparatus of the present invention, the flow direction of the molten aluminum alloy so as to be located at the same height as the upstream end surface of the molten metal supply nozzle or above the upstream end portion. It is preferable that a baffle plate extending upstream and satisfying the following is further provided, and the extension part and the baffle plate form the trap means.
Distance from the liquid surface of the molten aluminum alloy in the container to the lower surface of the baffle plate: 5 mm or more Length of the baffle plate in the flow direction of the molten aluminum alloy: 10 to 100 mm
Here, the thickness of the baffle plate is preferably 2 to 10 mm.

  In the continuous casting and rolling apparatus of the present invention, it is preferable that the distance from the liquid surface of the molten aluminum alloy in the vessel to the lower surface of the molten metal flow path is 15 to 250 mm.

  In the continuous casting and rolling apparatus of the present invention, it is preferable that the distance from the lower surface of the container to the lower surface of the molten metal flow path is 10 to 200 mm.

  The present invention also provides a method for producing an aluminum alloy plate for a lithographic printing plate support using the continuous casting and rolling apparatus of the present invention.

  The present invention also provides an aluminum alloy plate for a lithographic printing plate support produced using the continuous casting and rolling apparatus of the present invention.

  Moreover, this invention provides the aluminum alloy plate for lithographic printing plate supports manufactured using the method of this invention.

  In the continuous casting and rolling apparatus of the present invention, since a means for trapping foreign matters existing on the surface layer of the molten metal is provided, these foreign matters do not enter the molten metal supply nozzle, and these foreign matters are not produced on the continuous cast plate to be manufactured. Mixing is prevented. As a result, the produced continuous cast plate has no surface failure (melting surface foreign matter contamination failure) and the surface quality is improved.

The present invention will be described below with reference to the accompanying drawings.
[Continuous casting and rolling equipment]
FIG. 1 is an elevational view showing an embodiment of a continuous casting and rolling apparatus used in the method for producing an aluminum alloy plate for a lithographic printing plate according to the present invention. In FIG. 1, the wall surface on the near side of the drawing is omitted. This is also true for all elevations in the present application.

  In the continuous casting and rolling apparatus 1 shown in FIG. 1, an aluminum alloy molten metal (hereinafter referred to as “Al molten metal”) in which the Al ingot is melted and Fe, Si, etc. are added and adjusted to a desired composition in the melting and holding furnace 2. 100) is stored. Examples of the addition method of Fe, Si, and the like include a method of adding an Al—Fe (25 wt%) mother alloy, an Al—Si (25 wt%) mother alloy, or the like. A suitable composition of the molten Al will be described later.

The molten Al 100 in the melting and holding furnace 2 passes through the first flow path 3 and is sent to the filtering means 4.
A filter 41 for filtering the molten Al 100 is provided in the filtering means 4. The filter 41 provided in the filtering means 4 removes impurities mixed in the Al melt 100, melting furnace, contamination remaining in the melt flow path, and the like.

In the first flow path 3, it is preferable to add a master alloy containing TiB ₂ as the crystal grain refining material into the Al melt 100. This is because the addition of the crystal grain refining material tends to make the crystal grains fine during continuous casting, and in the surface treatment process when making a lithographic printing plate support, surface treatment unevenness caused by coarse crystal grains This is because generation can be suppressed.
Specifically, as the mother alloy containing TiB ₂ , for example, a wire-like mother alloy composed of Ti (5%), B (1%), and the balance of Al and inevitable impurities can be used.
In addition, when adding a crystal grain refining material, in order to suppress the outflow of TiB ₂ agglomerated particles, it is desirable to add it upstream from the filtering means 4.

  The Al molten metal 100 that has passed through the filtering means 4 passes through the second flow path 5 and flows into the container 6 for supplying the molten metal 100 to the molten metal supply nozzle 7. Although not shown, the container 6 is provided with a liquid level control mechanism for adjusting the inflow amount of the Al molten metal 100 and keeping the liquid level of the Al molten metal in the container 6 constant. As an example of the liquid level control mechanism, a valve (not shown) provided at the inlet of the container 6 is opened and closed according to a liquid level sensor (not shown) provided in the container 6. By adjusting the amount of the Al molten metal 100 flowing into the container 6 by changing the opening amount of the valve, the liquid level of the molten metal 100 in the container 6 is kept constant. Can be mentioned.

  The outlet side opening of the container 6 communicates with the molten metal flow channel 71 of the molten metal supply nozzle 7. The Al molten metal 100 that has passed through the molten metal flow path 71 supplies the Al molten metal 100 between the two cooling rollers 9 and 9 positioned at a constant distance (for example, about several mm to 10 mm). Thereby, casting rolling is performed. A continuous cast plate (aluminum alloy plate) 200 obtained by casting and rolling is wound up in a coil shape by a winding device 10. Moreover, it cut | disconnects suitably with a cutting machine (not shown).

In the continuous casting and rolling apparatus of the present invention, means for trapping foreign matter existing on the surface layer of the Al molten metal 100 (hereinafter simply referred to as “foreign matter trapping means”) is provided upstream of the molten metal supply nozzle 7.
As described above, as a method for preventing the black streak failure, various proposals have hitherto been made for means for preventing the TiB ₂ agglomerated particles that have settled and moved near the bottom of the molten metal from entering the cast plate. Has been made. FIG. 3 is a partially enlarged view showing the configuration of the container 6 and the molten metal supply nozzle 7 in the conventional continuous casting and rolling apparatus. The molten metal supply nozzle 7 shown in FIG. 3 is a general structure of the molten metal supply nozzle used for a continuous casting and rolling apparatus. The molten metal supply nozzle 7 shown in FIG. 3 includes an upper plate member 72 and a lower plate member 73, and a molten metal flow channel 71 exists between the upper plate member 72 and the lower plate member 73. As shown in FIG. 3, in the conventional continuous casting and rolling apparatus, the distance L ₂ from the bottom surface of the container 6 to the bottom surface of the molten metal flow path 71 is increased, that is, the molten metal flow path 71 is formed of the Al molten metal 100 of the container 6. By disposing the molten metal supply nozzle 7 so as to be close to the liquid level, TiB ₂ aggregated particles existing near the bottom of the container 6 were prevented from entering the molten metal flow channel 71 of the molten metal supply nozzle 7. . The range of L ₂ in the conventional continuous casting and rolling apparatus is typically 10 to 200 mm.

However, the oxide film 101 is usually present on the surface layer of the Al melt 100. In many cases, such an oxide film 101 contains impurities 102. Specific examples of such impurities include, for example, impurities including Mg and Ti with an Al oxide as the center.
In the conventional continuous casting and rolling apparatus, the molten metal flow path 71 of the molten metal supply nozzle 7 is disposed at a position close to the liquid level of the Al molten metal 100 in the container 6, so that the molten metal flow from the liquid level of the Al molten metal 100 in the container 6. The distance L ₃ to the upper surface of the channel 71 is small, and these foreign substances (the oxide film 101 and the impurities 102 present in the oxide film 101) existing on the surface layer of the Al melt 100 cannot be prevented from entering the melt channel 71. . When the Al molten metal 100 containing such foreign matter is supplied from the molten metal flow path 71 between the cooling rollers 9 and 9, it causes a failure of a continuously cast plate to be manufactured (melted surface foreign matter contamination failure).
The range of L ₃ in the conventional continuous casting and rolling apparatus is usually 2 to 10 mm.

FIG. 2 is a partially enlarged view showing a configuration example of the container 6 and the molten metal supply nozzle 7 in the continuous casting and rolling apparatus 1 of the present invention shown in FIG.
In FIG. 2, the upstream end surface of the molten metal supply nozzle 7, more specifically, the upstream surface of the upper plate member 72 of the molten metal supply nozzle 7 is hindered so as to extend in the substantially horizontal direction to the upstream side in the flow direction of the Al molten metal 100. A plate 8 is provided. As shown in FIG. 2, by providing the baffle plate 8, foreign matter (the oxide film 101 and the impurities 102 present in the oxide film 101) existing on the surface layer of the Al molten metal 100 enters the molten metal flow path 71. Is prevented. That is, in the configuration shown in FIG. 2, the baffle plate 8 is a foreign matter trapping means. However, in order for the baffle plate 8 to function as foreign matter trapping means, it is necessary to satisfy the following (1) to (3).

(1) The baffle plate 8 is located at the same height as the upper surface of the molten metal flow channel 71 near the upstream end of the molten metal supply nozzle 7 or above the upper surface.
As apparent from FIG. 2, if the baffle plate 8 is not located at the same height as the upstream end of the molten metal flow path 71 or above the upstream end, it exists on the surface layer of the Al molten metal 100. This is because it is impossible to prevent foreign substances (the oxide film 101 and the impurities 102 present in the oxide film 101) from entering the molten metal flow path 71. As shown in FIG. 2, when the baffle plate 8 has a thickness, the lower surface of the baffle plate 8 is the same height as the upper surface of the molten metal flow path 71 near the upstream end or from the upper surface. Must also be located above.

(2) The distance L ₅ from the liquid level of the Al molten metal 100 in the container 6 to the lower surface of the baffle plate 8 is 5 mm or more.
As shown in FIG. 2, the oxide film present on the surface layer of the Al melt 100 has a certain thickness. In order to prevent the oxide film 101 and the impurities 102 present in the oxide film 101 from entering the molten metal flow path 71, the baffle plate is provided below the oxide film 101 having such a certain thickness. 8 must be provided. Here, the oxide film 101 existing on the surface layer of the molten Al metal 100 usually has a thickness of about 3 mm or less. If L ₅ is 5 mm or more, the oxide film 101 existing on the surface layer of the Al molten metal 100 and This is sufficient to prevent the impurities 102 present in the oxide film 101 from entering the molten metal channel 71.
L ₅ is preferably 10 mm or more.
However, since the lower surface of the baffle plate 8 is located at the same height as the upper surface of the molten metal flow channel 71 near the upstream end portion or above the upper surface, if L ₅ is too large, the molten metal flow channel is accordingly increased. Since the position of 71 moves downward and the head pressure of the Al melt 100 when passing through the melt flow path 71 is different from the normal condition, it is not preferable. In this respect, L ₅ is preferably 50 mm or less, more preferably 30 mm or less, and further preferably 15 mm or less.
Further, since the lower surface of the baffle plate 8 is located at the same height as the upper surface of the molten metal flow path 71 near the upstream end or above the upper surface, the molten metal flow from the liquid surface of the Al molten metal 100 in the container 6 The distance L ₃ to the upper surface of the path 71 also needs to satisfy the conditions described for L ₅ . It should be noted that L ₃ and L ₅ are equal to each other as described below that the lower surface of the baffle plate 8 is located at the same height as the upper surface of the molten metal flow path 71 in the vicinity of the upstream end or above the upper surface. Although it is not necessary, the difference (L ₃ -L ₅ ) between the two is preferably 5 mm or less, more preferably 3 mm or less, and further preferably 1 mm or less.

(3) The length L ₆ of the baffle plate 8 in the flow direction of the molten aluminum alloy is 10 to 100 mm.
As apparent from FIG. 2, the oxide film 101 present on the surface layer of the Al melt 100 and the impurities 102 present in the oxide film 101 are the upstream end face of the melt supply nozzle 7, more specifically, the melt supply nozzle. 7, when the length of the baffle plate 8 is too short, the oxide film 101 existing on the surface layer of the Al melt 100 and the oxide film 101 exist. It is not possible to prevent the impurity 102 that enters from entering the molten metal flow path 71. When L ₆ is 10 mm or more, the oxide film 101 existing on the surface layer of the Al molten metal 100 existing on the surface layer of the Al molten metal 100 and the impurities 102 existing in the oxide film 101 are prevented from entering the molten metal flow path 71. Enough to do. L ₆ is preferably 10 mm or more, more preferably 20 mm or more, and further preferably 30 mm or more.
On the other hand, if L ₆ is too large, it will no longer contribute to preventing the oxide film 101 existing on the surface layer of the Al molten metal 100 and the impurities 102 present in the oxide film 101 from entering the molten metal flow path 71, and the baffle plate 8. This is not preferable because of an increase in the manufacturing cost, the possibility of damage to the baffle plate 8, and an increase in the flow resistance of the molten Al 100. From this point, the upper limit of L ₆ is set to 100 mm. L ₆ is preferably 80 mm or less, and more preferably 60 mm or less.

The thickness L ₇ of the baffle plate 8 is preferably 2 to 50 mm. If L ₇ is less than 2 mm, the mechanical strength of the baffle plate 8 may be insufficient. On the other hand, if L ₇ exceeds 50 mm, it has an excessive mechanical strength, and the manufacturing cost of the baffle plate 8 increases, which is not preferable.
L ₇ is more preferably 3 to 10 mm.

The preferred range of other dimensions in FIG.
The height L ₁ of the melting channel 71 is preferably 3 to 30 mm from the relationship between the cast finish plate thickness and the aluminum supply amount, more preferably 5 to 20 mm, and even more preferably 5 to 15 mm. .

The distance H ₂ from the liquid surface of the Al molten metal 100 in the container 6 to the lower surface of the molten metal flow path 7 is 15 to 250 mm, and the head pressure of the Al molten metal 100 when passing through the molten metal flow path 71 is normal. From the standpoint of preventing the difference, the thickness is preferably 15 to 250 mm, more preferably 20 to 100 mm.

The distance L ₂ from the lower surface of the container 6 to the lower surface of the molten metal flow path 7 is 10 to 200 mm in order to prevent the TiB ₂ aggregated particles moving on the bottom of the Al molten metal 100 from entering the molten metal flow path 71. It is preferable, it is more preferable that it is 30-150 mm, and it is further more preferable that it is 50-100 mm.

The thickness L ₄ of the upper plate member 72 is preferably 5 to 200 mm in order to achieve both mechanical strength and space securing, more preferably 10 to 150 mm, and more preferably 10 to 100 mm. More preferably.
On the other hand, the thickness of the lower plate member 73 is not particularly limited as long as the preferred range of L ₂ described above is satisfied.

FIG. 4 is a partially enlarged view showing another configuration example of the container 6 and the molten metal supply nozzle 7 in the continuous casting and rolling apparatus 1 of the present invention shown in FIG.
In FIG. 4, in the molten metal supply nozzle 7, the upstream end surface of the side including the upper surface of the molten metal channel 71 (that is, the upper plate member 72) is the side including the lower surface of the molten metal channel 71 (that is, the lower plate member 73. ) Is provided on the upstream side in the flow direction of the molten Al 100 with respect to the upstream end surface thereof. Here, a part of the upper surface of the molten metal flow path 71 is formed in the extension part 72 b so that the upper surface of the molten metal flow path 71 near the upstream end is lower than the upper surface of the remaining part of the molten metal flow path 71. A convex portion 72c protruding downward is provided.
As shown in FIG. 3, by providing the extended portion 72b having the convex portion 72c, foreign substances (the oxide film 101 and the impurities 102 existing in the oxide film 101) existing on the surface layer of the Al molten metal 100 are melted. Entering the flow path 71 is prevented. That is, in the configuration shown in FIG. 3, the extension part 72b having the convex part 72c is the foreign matter trapping means. However, in order for the extended portion 72b having the convex portion 72c to function as the foreign matter trapping means, it is necessary to satisfy the following (1) to (4).

(1) The distance H ₁ from the liquid surface of the Al molten metal 100 in the container 6 to the upper surface of the molten metal flow path 71 forming the convex portion 72c is ₁₀ to 200 mm.
The reason why the lower limit is provided for H ₁ is the same reason as that for providing the lower limit for L ₅ in the manner shown in FIG. However, the distance L ₃ from the liquid level of the Al molten metal 100 in the container 6 to the upper surface of the molten metal flow path 71, and the upper surface of the molten metal flow path 71 forming the convex portion 72 c and the upper surface of the remaining part of the molten metal flow path 71 ( In other words, the lower limit value of H ₁ is set to 10 mm in order to set the height difference L ₈ from the upper surface of the molten metal flow path 71 excluding the convex portion 72c to a range described later.
Note that the L _3, for the same considered L ₃ in the embodiment shown in FIG. 2, and more preferably preferably at 5mm or more, and 10mm or more.
On the other hand, the upper limit of H ₁ is set to 200 mm because the distance H ₂ from the liquid level of the Al molten metal 100 in the container 6 to the lower surface of the molten metal flow path 7 and from the lower surface of the container 6 to the lower surface of the molten metal flow path 7. in order to satisfy the preferred ranges for the distance L _2. Incidentally, H _2, and preferably a range of L ₂ is, H ₂ in the embodiment shown in FIG. 2, and is similar to the preferable range of L _2. The height preferable range of L ₁ launder is the same as the preferable range of L ₁ in the embodiment shown in FIG.
H ₁ is preferably 30 to 150 mm, and more preferably 30 to 100 mm.

(2) The height difference L ₈ between the upper surface of the molten metal flow channel 71 forming the convex portion 72c and the upper surface of the remaining portion of the molten metal flow channel 71 (that is, the upper surface of the molten metal flow channel 71 excluding the convex portion 72c) is 5-100 mm.
The reason why the lower limit value of L ₈ is set to 5 mm is the same reason as the lower limit value of L ₅ is set to 5 mm in the embodiment shown in FIG.
On the other hand, the reason why the upper limit value of L ₈ is set to 100 mm is that L ₃ and H ₁ are in the above-described range.
L ₈ is preferably 30 to 100 mm.

(3) the length L ₉ of the projections 72c in the flow direction of the molten Al 100 is 5 to 100 mm.
The reason why the lower limit value of L ₉ is set to 5 mm is to ensure the mechanical strength.
On the other hand, the upper limit value of L ₉ is set to 100 mm because the downstream end portion of the convex portion 72 c in the flow direction of the Al molten metal 100 and the upstream end surface (that is, the lower plate member 73 of the lower surface side of the molten metal flow channel 71). the upstream side end face), while satisfying the ranges specified below for the distance L ₁₁ of the the L ₉ and 100mm greater, because the extension portion 72b is too long.
L ₉ is preferably 5 to 50 mm, and more preferably 5 to 30 mm.

(4) The distance L ₁₁ between the downstream end portion of the convex portion 72 c in the flow direction of the Al molten metal 100 and the upstream end surface on the lower surface side of the molten metal flow channel 71 (that is, the upstream end surface of the lower plate member 73) 10-300 mm.
The lower limit value of L ₁₁ is set to 10 mm. When L ₁₁ is less than 10 mm, the flow path of the portion corresponding to L ₁₁ becomes too narrow compared to the height L ₁ of the molten metal flow path 71, and Al This is because the flow rate of the molten metal 100 increases and the TiB ₂ aggregated particles that move through the bottom of the Al molten metal 100 are rolled up.
On the other hand, the reason why the upper limit value of L ₁₁ is set to 300 mm is that when L ₁₁ exceeds 300 mm, the extension 72 b becomes too long.
L ₁₂ is preferably 10 to 100 mm, and more preferably 10 to 50 mm.

In FIG. 4, although the upper surface of the molten metal flow path 71 which forms the convex part 72c, and the lower surface of the molten metal flow path 71 are substantially the same height, the liquid of the Al molten metal 100 in the container 6 in the aspect shown in FIG. The distance H ₁ from the surface to the upper surface of the molten metal flow path 71 that forms the convex portion 72 c and the distance H ₂ from the liquid surface 100 of the Al molten metal in the container 6 to the lower surface of the molten metal flow path 71 satisfy the following expression: Is preferable for preventing foreign matters (the oxide film 101 and the impurities 102 present in the oxide film 101) existing on the surface layer of the Al molten metal 100 from entering the molten metal flow path 71.
0mm ≦ H ₁ − H ₂ ≦ 190mm
That is, the upper surface of the molten metal flow path 71 forming the convex portion 72 c and the lower surface of the molten metal flow channel 71 are at the same height, or the upper surface of the molten metal flow channel 71 forming the convex portion 72 c is lower than the lower surface of the molten metal flow channel 71. Is also preferably low. Here, the reason why the upper limit of H ₁ −H ₂ is set to 190 mm is to satisfy the above-described range for H ₁ and H ₂ .
However, if the distance H ₃ between the convex portion 72 c and the bottom surface of the container 6 is smaller than the height L ₁ of the molten metal flow path 71, the flow path in the portion corresponding to H ₃ becomes too narrow, and the Al molten metal 100 in this portion becomes too narrow. Will increase the TiB ₂ agglomerated particles that move through the bottom of the Al melt 100. Therefore, a H _3, and L _1, it is preferable to satisfy the relation as indicated in the following formula.
H ₃ ≧ L ₁

The preferred range of other dimensions in FIG. 4 is as follows.
The preferred range of the thickness L ₄ of the upper plate member 72 is the same as the preferred range of L ₄ in the embodiment shown in FIG.
It is preferred length L ₁₀ of the extension portion 72b is 15～400Mm. The reason why the lower limit value of L ₁₀ is set to 15 mm is to satisfy a preferable range for L ₉ and L ₁₁ . On the other hand, the reason why the upper limit value of L ₁₀ is set to 200 mm is that the extension portion 72b becomes too long when L ₁₀ exceeds 200 mm.
L ₁₀ is more preferably 15 to 200 mm.

FIG. 5 is a partially enlarged view showing another configuration example of the container 6 and the molten metal supply nozzle 7 in the continuous casting and rolling apparatus 1 of the present invention shown in FIG.
The embodiment shown in FIG. 5 corresponds to a combination of the embodiments shown in FIGS. 3 and 4, the baffle plate 8 and the extension 72 b having the convex portion 72 c are foreign matter trapping means, and foreign matter existing on the surface layer of the Al molten metal 100. In order to prevent (the oxide film 101 and the impurity 102) from entering the molten metal channel 71, it is most preferable. In addition, about the dimension of each part, it is the same as that of the aspect shown in FIG.

  A configuration that the continuous casting and rolling apparatus of the present invention preferably has will be described below. However, these are not essential components.

Although not shown, it is preferable to provide a degassing device in the middle of the first molten metal flow path 3 and perform a degassing process (dehydrogenation gas process) in the Al molten metal 100 before performing the filtration process. As the degassing device, a commercially available rotary degassing device such as SNIFF type or GBF can be used.
As the degassing treatment, techniques described in JP-A-5-51659, JP-A-5-49148, JP-A-7-40017, and the like may be used.

  As the filter 41 used for the filtering means 4, a ceramic tube filter, a ceramic foam filter, or the like is usually used. Specific examples of the filtering means include JP-A-6-57432, JP-A-3-162530, JP-A-5-140659, JP-A-4-231425, JP-A-4-276031, JP-A-5-312661, Examples thereof include those described in JP-A-6-136466 and Japanese Patent No. 3549080. Among these, those described in Japanese Patent No. 3549080 are preferable.

The Al molten metal 100 discharged from the molten metal supply nozzle 7 comes into contact with the surfaces of the cooling rolls 9 and 9 and starts to solidify. Here, when the molten Al moves from the tip of the molten metal supply nozzle 7 to the surfaces of the cooling rolls 9 and 9, a molten meniscus is formed. When this molten metal meniscus vibrates, the landing point on the cooling rolls 9 and 9 vibrates, and as a result, portions having different solidification histories are generated on the surface, resulting in uneven crystal structure and segregation of trace elements. . Such a failure is also called a ripple mark, and when subjected to surface treatment as a lithographic printing plate support after undergoing cold rolling, intermediate annealing, and finish cold rolling, it tends to cause surface treatment unevenness.
Therefore, from the viewpoint of reducing the ripple mark, in order to stabilize the detachment point of the Al molten metal in one place, the angle of the outer surface at least on the lower side of the molten metal supply nozzle 7 is at least relative to the discharge direction of the Al molten metal. It is preferable to incline so as to have an acute angle. For example, the method described in JP-A-10-58094 can be preferably used.

FIG. 6 is a schematic diagram illustrating a preferred example of the shape of the molten metal supply nozzle and the positional relationship with the cooling roller. In FIG. 6, only the upper plate member and the cooling roller of the molten metal supply nozzle are shown, but the lower plate member and the cooling roller 9 of the molten metal supply nozzle have the same positional relationship.
In FIG. 6, the outer edge of the mouth portion of the upper plate member 72 of the molten metal supply nozzle contacts the cooling roller 9, and an escape portion (chamfer portion) 72 d that avoids contact with the cooling roller 9 is provided on the outer periphery of the mouth portion of the upper plate member 72. It is recessed. That is, the upper plate member 72 is in contact with the cooling roller 9 only at the tip portion T. The escape portion (chamfered portion) is preferably provided over the entire width of the upper plate member 72.
By adopting such a structure, there is no gap as a space where the molten metal meniscus portion fluctuates, so that an aluminum alloy plate that does not cause an appearance failure can be obtained, and for lithographic printing plates in which the appearance failure is further suppressed. A support can be obtained.

Further, in order to reduce the amplitude when the meniscus vibrates, the distance between the tip of the molten metal supply nozzle (more specifically, the upper plate member and the lower plate member of the molten metal supply nozzle) and the surface of the cooling roller is reduced. preferable. Therefore, ideally, the melt supply nozzle (more specifically, the melt supply nozzle) in which the angle of the lower (preferably lower and upper) outer surfaces described above is an acute angle with respect to the discharge direction of the Al melt. It is preferable that the tip of the upper plate member and the lower plate member are always in contact with the surface of the cooling roller.
Specifically, for example, the upper plate member and the lower plate member constituting the molten metal supply nozzle are respectively movable in the vertical direction, and the upper plate member and the lower plate member are respectively applied by the pressure of the Al molten metal. A mode in which the pressure is pressed and pressed against the surface of the adjacent cooling roller is preferable. For example, the mode described in JP 2000-117402 A can be suitably used.
Thereby, the tip of the molten metal supply nozzle (more specifically, the upper plate member and the lower plate member of the molten metal supply nozzle) and the cooling roller are always in contact with each other, and as a result, the shape of the molten meniscus portion is maintained in a constant state. Therefore, it is possible to obtain a lithographic printing plate support in which appearance failure is further suppressed.

Even if the molten metal meniscus is stabilized in this way, if the flow of the molten metal in the molten metal nozzle is non-uniform, the continuously cast aluminum alloy plate tends to be non-uniform. Therefore, it is necessary to make the flow of the molten metal in the molten metal supply nozzle uniform, but the gap between the pair of cooling rollers is as small as several mm to 10 mm, so the molten metal supply nozzle also has a very thin structure, The molten metal flow path in the nozzle is also narrowed. Therefore, the stagnation of the Al molten metal in the molten metal flow path immediately leads to non-uniform Al molten metal flow.
In order to prevent stagnation of the Al molten metal in the molten metal flow path, it is preferable that the inner surface of the molten metal supply nozzle has low wettability with the Al molten metal. For this purpose, it is preferable that the inner surface of the molten metal supply nozzle is made of a material having low wettability with respect to the molten Al and has appropriate irregularities. Japanese Patent Application Laid-Open No. 10-225750 describes a method for defining the roughness of the inner surface of the molten metal supply nozzle.
Specifically, a mold release agent containing aggregate particles having a particle size distribution with a median diameter of 5 to 20 μm and a mode diameter of 4 to 12 μm is applied in advance to the inner surface of the molten metal supply nozzle in contact with the Al molten metal. Is preferred. Examples of the release agent that does not easily cause stagnation of the molten Al include a release agent that uses zinc oxide, boron nitride (BN), or the like as an aggregate. Among these, a release agent using boron nitride as an aggregate is preferable. For example, the method described in JP-A-11-192537 can be preferably used. For example, the method described in JP-A-11-192537 can be preferably used.

FIG. 7 is a schematic diagram illustrating another example of the molten metal supply nozzle having a movable tip. FIG. 7A is a plan view, and FIG. 7B is a side view.
In the molten metal supply nozzle shown in FIG. 7, the upper plate member 72 and the lower plate member 73 are fixed by the bar member 74, so that the tips of the upper plate member 72 and the lower plate member 73 are It can move slightly according to the pressure of the molten metal. Therefore, the tips of the upper plate member 72 and the lower plate member 73 can be brought into contact with the cooling roller by the pressure of the molten Al, respectively.

A cooling roller is not specifically limited, For example, conventionally well-known things, such as a cooling roller of iron core-shell structure, can be used. When using a cooling roller having a core / shell structure, the cooling ability of the surface of the cooling roller can be enhanced by passing cooling water through a channel provided between the core and shell. Further, by further reducing the solidified aluminum, the thickness of the aluminum alloy plate can be accurately adjusted to a desired thickness.
If the aluminum solidified on the surface of the cooling roller is left as it is, it tends to adhere to the cooling roller, and it may not be easy to cast it stably and continuously. Therefore, in the present invention, it is preferable that a release agent is applied to the surface of the cooling roller. As a mold release agent, what is excellent in heat resistance is preferable, For example, what contains carbon graphite is mentioned suitably. The method of application is not particularly limited, and for example, a method of spray-coating a suspension of carbon graphite particles (preferably an aqueous suspension) is preferable. Spray coating is preferable in that the release agent can be supplied in a non-contact manner to the cooling roller.

Here, if the thickness of the applied release agent is different in the width direction and / or the circumferential direction of the cooling roller, it affects the speed of heat transfer to the cooling roller, causing unevenness of crystal grains, Fe and In the present invention, it is preferable to make the thickness of the applied release agent uniform because it leads to non-uniform presence of Si.
Specifically, for example, a method in which a wiper made of a refractory material or a heat-resistant cloth is brought into contact with the surface of the cooling roller at a constant pressure is preferably exemplified. Further, when there is no risk of direct contact with the molten metal, a cloth such as cotton can be used to make it uniform.

  The release agent is preferably supplied to the surface of the cooling roller periodically in order to be captured by a homogenizing means such as a wiper or to move to the surface of a continuously cast aluminum alloy plate.

In addition, if the molten metal supply nozzle contacts the cooling roller in the width direction unevenly, the release agent on the surface of the cooling roller is partially scraped off, resulting in an inadequate thickness of the release agent on the roll surface. It tends to be uniform, and in turn tends to make crystal grains non-uniform.
Therefore, in the present invention, it is preferable that the outer edge of the mouth of the molten metal supply nozzle does not contact the cooling roller, and more preferably only contacts at the tip thereof from the viewpoint of reducing the ripple mark described above.

[Method for producing aluminum alloy plate for lithographic printing plate support]
In the method for producing an aluminum alloy plate for a lithographic printing plate support, a continuous cast plate (aluminum alloy plate) is prepared using the continuous casting and rolling apparatus of the present invention, and then cold rolling, intermediate annealing, and finish cooling are performed in a normal procedure. Perform hot rolling and flatness correction. These procedures and the preferred composition of the molten Al used for the production of continuous cast plates (aluminum alloy plates) will be described below.

[Preferred composition of molten aluminum]
The preferred composition of the molten Al will be described below.

Si is an element contained as an inevitable impurity in an Al ingot, which is a raw material, in an amount of about 0.03 to 0.1 wt%, and is often intentionally added in a small amount to prevent variation due to a difference in raw materials. Si is present in a solid solution in aluminum, or as an intermetallic compound or a single precipitate.
In the present invention, the amount of Si in the molten Al is preferably 0.04 to 0.15 wt%. In addition, the value of 0.10 wt% or more is implemented by adding a mother alloy separately in addition to Si in the Al metal.

Fe has a small amount of solid solution in aluminum, and most remains as an intermetallic compound. Moreover, Fe has the effect | action which raises the mechanical strength of an aluminum alloy, and has a big influence on the intensity | strength of a support body.
If the Fe content is too small, the mechanical strength is too low, and it becomes easy to cause plate breakage when the lithographic printing plate is attached to the plate cylinder of a printing press. Further, when printing a large number of copies at high speed, the plate is likely to be cut out similarly.
On the other hand, when the Fe content is too large, the strength becomes higher than necessary, and when the lithographic printing plate is attached to the plate cylinder of a printing press, the fitness is inferior, and the plate is likely to be cut during printing. Further, if the Fe content is greater than 1.0 wt%, for example, cracks are likely to occur during rolling.
In the present invention, the amount of Fe in the molten Al is preferably 0.10 to 0.50 wt%.

Cu is an important element in controlling the electrolytic surface roughening treatment. Further, Cu is an element that is very easy to dissolve, and a small part exists as an intermetallic compound.
In the present invention, the amount of Cu in the molten Al is preferably 0.001 wt% or more from the viewpoint of the uniformity of the electrolytic surface roughening, and the pits generated by the electrolytic surface roughening treatment in nitric acid solution. From the viewpoint of the uniformity of the diameter and the pit diameter, and hence the stain resistance, it is preferably 0.050 wt% or less.

The molten aluminum can contain elements (for example, Ti, B) that refine crystal grains in order to prevent cracking during casting. It is preferable to sufficiently refine the crystal at the time of casting because the width of the crystal grains becomes small even after finish cold rolling.
For example, Ti can be contained in the range of 0.003 to 0.05 wt%. Moreover, B can be contained in 0.001-0.02 wt% of range.

Moreover, the remainder of Al molten metal consists of Al and an unavoidable impurity. Examples of inevitable impurities include Mg, Mn, Zn, Cr, Zr, V, Zn, and Be. These can each be contained in a range of 0.05 wt% or less.
Most of the inevitable impurities are contained in the Al ingot. If the inevitable impurities are contained in, for example, a metal having an Al purity of 99.7 wt%, the effects of the present invention are not impaired. For inevitable impurities, see, for example, L.A. F. The amount of impurities described in Mondolfo's “Aluminum Alloys: Structure properties” (1976) and the like may be contained.

  Next, procedures of cold rolling, intermediate annealing, finish cold rolling, and flatness correction will be described in this order.

<Cold rolling>
In the continuous casting and rolling device 1 shown in FIG. 1, cold rolling is performed on a continuous cast plate (aluminum alloy plate) 200 that is appropriately cut by a cutting machine (not shown) and wound in a coil shape by the winding device 10. I do. Cold rolling is a procedure for reducing the thickness of a continuous cast plate (aluminum alloy plate) 200 manufactured by the continuous cast rolling apparatus 1 shown in FIG. As a result, the continuous cast plate (aluminum alloy plate) 200 has a desired thickness. The cold rolling can be performed by a conventionally known method. FIG. 8 is a schematic diagram showing an example of a cold rolling mill used for cold rolling. The cold rolling mill 11 shown in FIG. 8 includes a pair of rolling rollers 14 each rotated by a support roller 15 on a continuous cast plate (aluminum alloy plate) 200 conveyed between the feeding coil 12 and the winding coil 13. Apply cold pressure and cold rolling.

<Intermediate annealing>
After cold rolling, intermediate annealing is performed. Intermediate annealing is a procedure for performing a heat treatment on a continuous cast plate (aluminum alloy plate) after cold rolling.
Originally, the continuous casting method can cool and solidify the molten metal very rapidly, unlike the conventional method using a fixed mold. As a result, the crystal grains in the continuous cast plate (aluminum alloy plate) obtained through continuous casting can be remarkably refined as compared with the conventional method using a fixed mold. However, as it is, the size of the crystal grains is still large. After finishing cold rolling, when the surface of the lithographic printing plate is further subjected to a roughening treatment, an appearance failure due to the size of the crystal grains (surface Uneven processing) is likely to occur.
Therefore, after accumulating the processing strain in the cold rolling process described above, the intermediate annealing process is performed, so that the dislocations accumulated in the cold rolling process are released, recrystallization occurs, and the crystal grains are further refined. Will be able to. Specifically, the crystal grains can be controlled by the processing rate in the cold rolling process and the heat treatment conditions in the intermediate annealing process (in particular, the temperature, time, and heating rate). For example, when continuous annealing is performed, heating is usually performed at 300 to 600 ° C. for 10 minutes or less, preferably heating at 400 to 600 ° C. for 6 minutes or less, and heating at 450 to 550 ° C. for 2 minutes or less. Is more preferable. Usually, the rate of temperature rise is about 0.5 to 500 ° C./minute, but the rate of temperature rise is 10 to 200 ° C./second or more, and the holding time after the temperature rise is short (within 10 minutes) (Preferably within 2 minutes), the refinement of crystal grains can be promoted.
When batch-type annealing is used, it is usually heated at 300 to 550 ° C. for 5 hours or longer, but preferably heated at 300 to 500 ° C. for 10 hours or longer, and heated at 350 to 490 ° C. for 10 hours or longer. More preferred. The upper limit of the annealing time for each temperature is preferably 40 hours or less.
The intermediate annealing can be performed by a conventionally known method. Specifically, JP-A-6-220593, JP-A-6-210308, JP-A-7-54111, JP-A-8-92709, etc. Can be used.

<Finish cold rolling>
After the intermediate annealing, finish cold rolling is performed. Finish cold rolling is a procedure for reducing the thickness of a continuous cast plate (aluminum alloy plate) after intermediate annealing. The thickness after the finish cold rolling is preferably 0.1 to 0.5 mm.
Cold rolling can be performed by a conventionally known method. For example, it can be performed by a method similar to the cold rolling performed before the intermediate annealing described above.

<Flatness correction>
Flatness correction is a process of correcting the flatness of a continuous cast plate (aluminum alloy plate).
Flatness correction can be performed by a conventionally known method. For example, it can be performed using a correction device such as a roller leveler or a tension leveler.
The flatness correction may be performed after the aluminum alloy plate is cut into a sheet shape, but is preferably performed in a continuous coil state from the viewpoint of improving productivity.
FIG. 9 is a schematic diagram illustrating an example of a correction device. The straightening device 20 shown in FIG. 9 applies tension to the continuous cast plate (aluminum alloy plate) 200 conveyed between the feed coil 22 and the take-up coil 23 at the leveler unit 21 including the work roll 24. Improve flatness. Thereafter, the slitter 25 adjusts the plate width to a predetermined width.

  Moreover, in order to process the plate width into a predetermined width, a slitting process through a slitter line can be performed. A slit process can be performed by a conventionally well-known method.

  Moreover, in order to prevent the generation | occurrence | production of the damage | wound by friction between aluminum alloy plates, the oil film formation process which provides a thin oil film on the surface of an aluminum alloy plate can also be performed. As the oil film, a volatile or non-volatile film is appropriately used as necessary.

  The surface of the aluminum alloy plate obtained by the above procedure is mechanically, electrically, chemically, electrochemically, or roughened by a combination of two or more thereof and finished to a lithographic printing plate support. This lithographic printing plate support is provided with a photosensitive coating film, exposed to an image, developed and subjected to plate making, thereby completing a photosensitive lithographic printing plate. This photosensitive lithographic printing plate can be manufactured with high quality as the surface quality of the continuous cast plate (aluminum alloy plate) is improved.

FIG. 1 is an elevation view showing an embodiment of a continuous casting and rolling apparatus of the present invention. FIG. 2 is a partially enlarged view showing a configuration example of the container 6 and the molten metal supply nozzle 7 in the continuous casting and rolling apparatus shown in FIG. FIG. 3 is a partially enlarged view showing a configuration example of the container 6 and the molten metal supply nozzle 7 in the conventional continuous casting and rolling apparatus. FIG. 4 is a partially enlarged view showing another configuration example of the container 6 and the molten metal supply nozzle 7 in the continuous casting and rolling apparatus shown in FIG. FIG. 5 is a partially enlarged view showing still another configuration example of the container 6 and the molten metal supply nozzle 7 in the continuous casting and rolling apparatus shown in FIG. FIG. 6 is a schematic diagram showing a preferred example of the shape of the molten metal supply nozzle and the positional relationship with the cooling roller. 7 (a) and 7 (b) are schematic views showing another example of the molten metal supply nozzle having a movable structure at the tip, FIG. 7 (a) is a plan view, and FIG. 7 (b) is a side view. is there. FIG. 8 is a schematic diagram showing an example of a cold rolling mill used for cold rolling. FIG. 9 is a schematic diagram illustrating an example of a correction device.

Explanation of symbols

1: Continuous casting and rolling apparatus 2: Melting and holding furnace 3: First flow path 4: Filtering means 41: Filter 5: Second flow path 6: Container 7: Molten metal supply nozzle 71: Molten metal flow path 72: Upper plate member 72b: Extension part 72c: Convex part 72d: Escape part (chamfered part)
73: Lower plate member 74: Bar member 8: Baffle plate 9: Cooling roller 10: Winding device 11: Cold rolling mill 12: Feeding coil 13: Winding coil 14: Rolling roller 15: Support roller 20: Correction device 21 : Leveler part 22: Sending coil 23: Winding coil 24: Work roll 25: Slitter 100: Molten aluminum 200: Continuous cast plate (aluminum alloy plate)
T: The tip of the molten metal supply nozzle

Claims (11)

Melt feed nozzle having a melt channel therein, a pair of cooling rollers where the aluminum alloy melt from solution the hot water supply nozzle is supplied, and an aluminum alloy plate having at least a container for supplying molten aluminum alloy solution hot water supply nozzle A continuous casting and rolling device of
Means for trapping foreign matter present on the surface layer of the molten aluminum alloy is provided on the upstream side of the molten metal supply nozzle ,
Flow direction of the molten aluminum alloy from the upstream end surface of the melt supply nozzle so as to be the same height as the upper surface of the melt flow path near the upstream end of the melt supply nozzle or above the upper surface A continuous casting and rolling apparatus for an aluminum alloy plate, characterized in that a baffle plate that extends in a substantially horizontal direction on the upstream side and that satisfies the following is provided, and the baffle plate is the trap means .
Distance from the surface of the molten aluminum alloy in the container to the bottom surface of the baffle plate: 5 mm or more
Length of the baffle plate in the flow direction of the molten aluminum alloy: 10 to 100 mm The apparatus for continuously casting and rolling an aluminum alloy plate according to claim 1, wherein the thickness of the baffle plate is 2 to 10 mm. An aluminum alloy plate comprising at least a molten metal supply nozzle having a molten metal flow path therein, a pair of cooling rollers to which molten aluminum alloy is supplied from the molten metal supply nozzle, and a container for supplying molten aluminum alloy to the molten metal supply nozzle A continuous casting and rolling device,
Means for trapping foreign matter present on the surface layer of the molten aluminum alloy is provided on the upstream side of the molten metal supply nozzle,
In the molten metal supply nozzle, an upstream end surface on the side including the upper surface of the molten metal flow path is positioned upstream of the upstream end surface on the side including the lower surface of the molten metal flow path in the flow direction of the molten aluminum alloy. The aluminum alloy melt is provided with an extension that extends upstream in the flow direction of the molten metal and that satisfies the following:
In the extension portion, a part of the upper surface of the molten metal channel protrudes downward so that the upper surface of the molten metal channel near the upstream end is lower than the upper surface of the remaining portion of the molten metal channel. And the convex part which satisfy | fills the following is provided, and this extension part is the said trap means, The continuous casting rolling apparatus of the aluminum alloy plate characterized by the above-mentioned.
Distance from the liquid surface of the molten aluminum alloy in the container to the upper surface of the molten metal flow path forming the convex portion: 10 to 200 mm
Length of the convex portion in the flow direction of the molten aluminum alloy: 5 to 100 mm
Difference in height between the upper surface of the molten metal flow path forming the convex portion and the upper surface of the remaining portion of the molten metal flow path: 5 to 100 mm
The distance between the downstream end portion of the convex portion in the flow direction of the molten aluminum alloy and the upstream end surface on the lower surface side of the molten metal flow path: 10 to 300 mm The distance from the surface of the molten aluminum alloy in the vessel to the upper surface of the molten metal flow path forming the convex portion is H ₁ , The distance from the liquid level of the molten aluminum alloy in the vessel to the lower surface of the molten metal flow path is H ₂ The continuous casting and rolling apparatus for aluminum alloy sheets according to claim 3, wherein:
0mm ≤ H ₁  -H ₂   ≦ 190mm There is further provided a baffle plate extending to the upstream side in the flow direction of the molten aluminum alloy and satisfying the following so as to be located at the same height as the upstream end surface of the molten metal supply nozzle or above the upstream end portion. The continuous casting and rolling apparatus for an aluminum alloy plate according to claim 3 or 4, wherein the extension portion and the baffle plate serve as the trap means.
Distance from the surface of the molten aluminum alloy in the container to the bottom surface of the baffle plate: 5 mm or more
Length of the baffle plate in the flow direction of the molten aluminum alloy: 10 to 100 mm The thickness of the said baffle plate is 2-10 mm, The continuous casting rolling apparatus of the aluminum alloy plate of Claim 5. The continuous casting and rolling apparatus for aluminum alloy sheets according to any one of claims 1 to 6, wherein a distance from the liquid surface of the molten aluminum alloy in the vessel to the lower surface of the molten metal flow path is 15 to 250 mm. . The distance from the lower surface of the said container to the lower surface of the said molten metal flow path is 10-200 mm, The continuous casting rolling apparatus of the aluminum alloy plate in any one of Claims 1-7 characterized by the above-mentioned. A method for producing an aluminum alloy plate for a lithographic printing plate support using the continuous casting and rolling apparatus according to any one of claims 1 to 8. An aluminum alloy plate for a lithographic printing plate support produced using the continuous casting and rolling apparatus according to any one of claims 1 to 8. An aluminum alloy plate for a lithographic printing plate support produced using the method according to claim 9.

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