JP2010248367A - Method of manufacturing plate-like water-containing gel of water-soluble polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a plate-like water-containing gel of a water-soluble polymer stably continuously while preventing adhesion of the plate-like water-containing gel of the water-soluble polymer such as (meth)acrylic acid- or (meth)acrylate-based water-soluble polymer to a belt base material. <P>SOLUTION: When the plate-like water-containing gel of the water-soluble polymer is manufactured continuously by polymerizing a polymerizable monomer on a surface of the belt base material using a belt polymerizing machine having a stainless steel-made belt base material, the plate-like water-containing gel is peeled from the surface of the belt base material with a reciprocating peeling member by intermittently giving a stress to a contact point of the water-containing gel with the surface of the belt base material while horizontal or downward tensile tension is given to the water-containing gel at the end of the belt polymerizing machine. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

The present invention relates to an efficient method for producing a water-soluble polymer plate-like hydrogel in a belt polymerization machine. More specifically, the present invention relates to a method for producing a plate-like hydrous gel of a (meth) acrylic acid (salt) -based water-soluble polymer. More specifically, for removing water-containing gel, which is the pre-drying stage of (meth) acrylic acid (salt) -based water-soluble polymer, which is widely used in various fields such as medicine, paint, manufacturing process, civil engineering and construction The present invention relates to a production method using an efficient belt polymerization machine in which a device is used to promote separation from a belt substrate.

Conventionally, water-soluble polymers are known to exhibit properties such as cohesion and thickening, and (meth) acrylic acid (salt) water-soluble polymers are particularly excellent in these properties. As industrially useful. For example, in the pharmaceutical field, it is used as an additive or hydrophilic ointment base for the purpose of improving the adhesiveness and water retention of poultices and poultices. In the paint field, it is used as a thickener for carpet compounds, paints. It is used as a thickener, adhesive, and tackifier. In the field of production processes, it is frequently used as a red mud settling agent during alumina production and a flocculant for salt water purification in the soda industry. Furthermore, in the civil engineering and construction fields, it is used as a drilling soil treatment agent, dredged soil treatment agent, and a mud additive, and in other general industrial fields, food additives, moisture absorbents, desiccants, surface modifiers, various thickening agents. It is also used as an agent. As described above, (meth) acrylic acid (salt) -based water-soluble polymers are widely used in various fields.

  Such a (meth) acrylic acid (salt) -based water-soluble polymer is produced, for example, through a polymerization step, a gel crushing step, a drying step, and the like, and is usually (meth) acrylic acid (salt) -based by aqueous solution polymerization. A water-soluble polymer plate-like hydrated gel (hereinafter also simply referred to as “hydrated gel” or “gel”) will be produced. Since the (meth) acrylic acid (salt) -based water-soluble polymer plate-like hydrogel has adhesion, the hydrogel obtained by polymerization may adhere strongly to the bottom surface of the polymerization vessel, etc. A step of peeling off the hydrogel is essential.

In particular, such a (meth) acrylic acid (salt) -based water-soluble polymer is in a method for continuously producing a water-soluble polymer plate-like hydrogel by a belt polymerizer such as an optical belt polymerization method. In some cases, the plate-like hydrogel may cause adhesion to the belt base material. In such a case, a process of peeling the hydrogel from the belt base material is indispensable and continuously produced. I can't. Further, when the degree of adhesion is strong, the water-soluble polymer plate-like hydrated gel is entrained to the lower side of the polymerization machine at the end of the belt base material, causing a great problem that the process is stopped.
In the conventional belt polymerization machine, there is a case where a fixed scraper or the like is installed for the purpose of peeling the gel. However, in the case of a sticky plate-like hydrous gel, the plate-like hydrous gel is used due to the clearance between the scraper and the belt substrate. Has the disadvantage that it enters the direction of travel of the belt substrate.

Japanese Patent Laying-Open No. 2006-45357 (second page 11-13, etc.) JP 2007-56222 A (Pages 2, 13-18, etc.) JP 2006-213773 A (2nd page etc.) JP 2003-261626 A (second page, etc.) JP 2002-3509 A (pages 2, 6 etc.)

The present invention has been made in view of the above situation, and for example, while preventing adhesion of a water-soluble polymer plate-like hydrous gel such as a (meth) acrylic acid (salt) -based water-soluble polymer to a belt base material. It is an object of the present invention to provide a method for producing a water-soluble polymer plate-like hydrous gel stably and continuously.

According to the study by the present inventors, instead of installing a scraper fixed where the plate-like hydrous gel is lifted from the belt substrate, a horizontal or downward tensile tension is applied at the end of the belt polymerization machine. Stress is applied to the lower surface of the plate-like hydrous gel and at least one point using a peeling member movable back and forth toward the contact point between the plate-like hydrogel and the stainless steel belt base material. It has been found that the above-mentioned object can be achieved by giving the above, and the present invention has been completed based on this finding.

  That is, the present invention continuously produces a water-soluble polymer plate-like hydrogel by polymerizing a polymerizable monomer on the belt base material surface using a belt polymerization machine having a stainless steel belt base material. At the end of the belt polymerization machine, a peeling member that reciprocates while applying a tensile force in the horizontal or downward direction to the hydrated gel is intermittently directed toward the contact point between the hydrated gel and the belt substrate surface. A method for producing a water-soluble polymer plate-like hydrogel, characterized in that stress is applied to the plate to peel the plate-like hydrogel from the belt substrate surface.

By adopting the present invention, even if the plate-like hydrous gel adheres to the metal belt, peeling is appropriately promoted, so that continuous production over a long period of time is possible with a belt polymerization apparatus. As a result, the production efficiency is improved, and it is possible to reduce the costs such as the equipment cost and the labor cost and make it economically advantageous.

It is explanatory drawing which showed the one aspect | mode which implements the manufacturing method of this invention using the belt polymerization machine which has a stainless steel belt base material.

In the present specification, “belt” is also referred to as “belt substrate” or “continuous belt substrate”, and “belt surface” is also referred to as “belt substrate surface”. In other words, the belt substrate is also a substrate belt. For example, “metal belt substrate” is also referred to as “metal substrate belt”, and “continuous belt substrate” is also referred to as “continuous substrate belt”. The belt polymerization machine is also referred to as a belt polymerization apparatus. "Terminal part" is a part where a plate-like hydrogel is tensioned horizontally or downward from the surface of the belt base material on the belt base material, strictly limited to the folded portion of the belt base material in the belt polymerization machine. is not. “Clearance” means a clearance between a belt substrate and a scraper in the present specification. The continuous belt substrate may be a belt substrate on a belt polymerization machine that enables continuous production of the hydrogel.

  The present invention will be described with reference to FIG. The roll (1) is provided at the end of the belt polymerization machine, and the hydrogel (G) carried on the belt substrate is subjected to its own weight or a downward tension applied to the gel. It is transported to the next process (gel cutting, pulverization, drying process, etc.) over the transport roll (2). At that time, in the present invention, the peeling member (3) is installed, and the contact point between the hydrogel and the belt base material surface is intermittently pushed by the tip portion of the member while continuously or intermittently reciprocating the member. Apply stress. By doing so, the hydrogel is smoothly peeled from the belt base material surface over a long period of time.

The angle at which the gel (G) is pulled horizontally or downward is θ = 5 to 180, preferably 10 when the angle formed by the vertical plane passing through the center of the rotation axis (4) and the plane of the gel is θ °. -90, more preferably 15-60, particularly preferably 20-45. The tension applied to the gel (G) is 0.1 to 5 N / cm ² , preferably 0.5 to ³ N / cm ² , most preferably due to the gel's own weight.

  Since the peeling member intermittently applies stress to the lower surface of the plate-like hydrogel, that is, the lower surface of the plate-like hydrogel and toward the contact point between the plate-like hydrogel and the stainless steel belt substrate, the belt polymerization machine The water-containing gel is continuously peeled off from the belt surface in contact with the water-containing gel. In order to save the trouble of observing whether or not adhesion to the belt base material occurs, it is preferable to apply the stress continuously during production.

  The form for peeling off is not particularly limited, but at the initial stage of polymerization, that is, when the end portion of the hydrogel attached to the belt substrate surface is first peeled off from the belt substrate surface, The plate-like hydrogel is peeled off by human power or some device.

  Preferably, the continuous reciprocating motion is in a form along the traveling direction of the belt base material of the belt polymerization machine or in a direction substantially parallel to the traveling direction. In other words, a preferred embodiment of the production method of the present invention is a mode in which stress is applied by a peeling member that reciprocates in a direction substantially parallel to the traveling direction of the belt base material of the belt polymerization machine. Here, “reciprocating in a direction substantially parallel to the traveling direction of the belt base material of the belt polymerization machine” means reciprocating motion along the traveling direction of the belt base material of the belt polymerization machine.

  The reciprocating motion of the peeling member on the belt base material is preferably performed through a device for operating a peeling member (butting bar) attached to the outlet or end point of the belt polymerization machine. The operation device is not particularly limited as long as it is a device capable of imparting a reciprocating motion to a member. For example, a rotating shaft from a motor is an extended crankshaft, which is partially fixed to a gantry, and the rotating motion from the motor is converted into a lateral motion by the crank, causing the peeling member to reciprocate. Can do.

  Further, the peeling member may be connected to a hydraulic piston device. In that case, the operation timing, interval, etc. of the peeling member are appropriately set by the hydraulic piston. Of course, other known operating devices may be used.

  Moreover, you may use together the form which the said member for peeling moves to a belt surface right and left. In the present specification, it is also possible to adopt a form in which one of the edge ropes installed on both sides of the belt base material is moved to the left and right so that the other is moved to the left and the other is moved to the right. By moving the peeling member in this manner, it is possible to efficiently apply intermittent stress to the tip surface of the plate-like gel or the lower surface of the plate-like hydrous gel.

  The size of the peeling member can be appropriately set according to the size of the belt polymerization machine or the hydrogel in the production method of the present invention. For example, the maximum width of the peeling member is 1 cm or more. Is preferable, more preferably 2 cm or more, and still more preferably 3 cm or more. The upper limit is preferably 10 cm, for example. For example, the length of the peeling member is preferably 20 cm or more, more preferably 30 cm or more, and still more preferably 50 cm or more. The upper limit is preferably 200 cm, for example.

  The magnitude | size of the said belt base material can be suitably set according to the production scale in the manufacturing method of this invention. The width of the belt base material in the actual manufacturing apparatus is preferably, for example, 30 cm or more, more preferably 50 cm or more, and further preferably 100 cm or more. For example, the upper limit is preferably 200 cm, more preferably 180 cm, and still more preferably 160 cm.

  If there is no thrusting action (reciprocating motion) of the peeling member against the hydrous gel surface according to the present invention, manual monitoring may be required, which complicates the process. In addition, once the continuous hydrogel adheres to the belt base material during continuous production, the phenomenon of entrainment in the lower part of the belt polymerization machine or the phenomenon of lifting onto the belt base material occurs. Becomes impossible and causes a great number of problems.

  However, the above-mentioned problems can be solved by employing a plate-like hydrogel production apparatus that employs an apparatus that can impart a pushing action (reciprocating motion) to the hydrogel surface of the peeling member according to the present invention.

In the method for producing the water-soluble polymer plate-like hydrogel of the present invention, the peeling member preferably has a surface hardness higher than that of the plate-like water-containing gel and lower than that of the stainless steel belt substrate.
That is, although it is a material of the said peeling member, if the material of the peeling member is a material whose surface hardness is higher than a plate-like water-containing gel, it is suitable when the manufacturing method of this invention exhibits the effect of this invention. It becomes a form. In addition, if the material is softer than the belt surface (belt base material) in contact with the hydrogel of the belt polymerization machine, that is, if the material of the peeling member is softer than the stainless steel base material, Since it is hard to be damaged, it can be preferably used.
For example, when the material of the belt base material is SUS (Vickers hardness, approximately 550 N / mm2), the peeling member is made of a material having a Vickers hardness of 400 N / mm2 or less, preferably 300 N / mm2 or less. preferable. More preferably, it is 200 N / mm 2 or less. More preferably, it is 150 N / mm 2 or less. The lower limit is preferably 10 N / mm 2 or more, more preferably 20 N / mm 2 or more, and still more preferably 50 N / mm 2 or more.

  For example, brass, which is a typical soft metal, has a Vickers hardness of about 100 N / mm 2 and can be said to be a more preferable material. In addition, the measurement of Vickers hardness is defined by JIS Z2251. In principle, this is obtained by dividing the amount of load applied to the material by the surface area calculated by measuring the diagonal length of the indenter mark. Further, the Vickers hardness is a method in which a diamond square pyramid (indenter) having a facing angle of 136 ° is pressed into a measurement object with a constant load, and the hardness is measured by the size of a hollow formed.

In the method for producing a water-soluble polymer plate-like hydrogel of the present invention, the peeling member is preferably at least one selected from the group consisting of a resin and a soft metal.
Thereby, it becomes possible to give sufficient stress intermittently by the peeling member, and the peeling member can have a strength that can withstand continuous use. It is possible to substantially prevent the scratches on the surface, and the production method of the present invention becomes more efficient and safe.

  As described above, the soft metal only needs to have a surface hardness higher than that of the plate-like hydrogel and lower than that of the stainless steel belt base material, and is softer than stainless steel according to the general definition of metal hardness. Anything that can be evaluated. Specifically, if the surface hardness of the soft metal is 50 N / mm 2 or more as Vickers hardness specified in JIS Z2251, sufficient stress can be applied to the hydrogel, 300 N / mm 2 If the following is adopted, the SUS metal belt base material is hardly damaged. That is, it is a preferred embodiment of the present invention that the soft metal has a surface hardness of 50 to 300 N / mm 2 according to Vickers hardness defined in JIS Z2251. As a lower limit, More preferably, it is 60 N / mm2, More preferably, it is 80 N / mm2. As an upper limit, More preferably, it is 280 N / mm <2>, More preferably, it is 260 N / mm <2>. Examples of the soft metal include copper, tin, zinc, lead, aluminum, and alloys thereof such as brass. Of these, brass is preferable.

  A form in which the material of the peeling member is a resin is also a preferred form of the present invention. Examples of the resin include polystyrene resins, acrylonitrile butadiene styrene (ABS) resins, styrene resins such as acrylonitrile / ethylene-propylene-diene / styrene (AES) resins, acrylonitrile styrene (AS) resins; methacrylic resins; polycarbonate resins; Polyphenylene ether (PPE) resin; and the like. Among these, polyolefin resins such as polyethylene resin and polypropylene resin, and fluororesins can be preferably used. It is preferable to employ a relatively solvent-resistant resin. Among these, a fluororesin is more preferable, and Teflon (registered trademark) is more preferable. If it is a fluororesin, it can be said that it is a preferable material since hardness is moderate and it is hard to generate | occur | produce problems, such as adhesion of plate-like hydrogel to the resin surface. The preferable surface hardness of the resin is the same as the preferable surface hardness of the soft metal described above.

1. Roll 2. Roll 3. 3. Peeling member Rotation axis G. gel

Claims (5)

When a water-soluble polymer plate-like hydrous gel is continuously produced by polymerizing a polymerizable monomer on the belt base material surface using a belt polymerizer having a stainless steel belt base material, the belt polymerizer At the terminal end of the water gel, by applying a tensile force in the horizontal or downward direction to the water-containing gel, by applying a reciprocating peeling member, intermittent stress is applied toward the contact point between the water-containing gel and the belt base material surface, A method for producing a water-soluble polymer plate-like water-containing gel, comprising peeling off the plate-like water-containing gel from the belt base material surface. The manufacturing method according to claim 1, wherein the peeling member reciprocates in a direction substantially parallel to the traveling direction of the belt base material of the belt polymerization machine. The manufacturing method according to claim 1 or 2, wherein the peeling member has a surface hardness higher than that of the plate-like hydrogel and lower than that of the stainless steel belt base material. The manufacturing method according to claim 2, wherein the peeling member is at least one selected from the group consisting of a resin and a soft metal. The manufacturing method according to claim 4, wherein the soft metal has a surface hardness of 50 to 300 N / mm 2 according to Vickers hardness defined in JIS Z2251.

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