JP5351983B2 - Method for producing latex foam - Google Patents

Description

  The present invention relates to a production method for producing a latex foam by foaming a latex of rubber or resin by stirring.

Since latex of rubber and resin is excellent in processability for processing into various article shapes and can form articles having excellent strength and the like, for example, rubber gloves (not only those made of rubber but also gloves made of resin) The same applies to the following, etc.) and is widely used as a forming material.
For example, after immersing the mold corresponding to the three-dimensional shape of the rubber glove in the latex and pulling it up, the latex adheres to the surface of the mold, and in the case of rubber latex, the mold is heated and vulcanized together. In the case of a resin latex, it is dried and further cured as necessary, and then removed from the mold, thereby producing a rubber glove corresponding to the complicated three-dimensional shape of the mold.

Further, when the latex is foamed by stirring to form a latex foam containing air, and the latex foam is used as a material for forming an article such as the rubber glove, the formed article has a porous structure and has characteristics such as flexibility. There is an advantage that it can be improved, new properties such as liquid absorbability can be imparted, and the weight of the article can be reduced.
The added value of an article formed using latex foam is determined by the size (average bubble diameter) and amount (bubble content) of bubbles contained in the article. Therefore, it is important to control the average bubble diameter and bubble content of the latex foam that affects these.

In particular, the average cell diameter is important, and the smaller the average cell size, the denser the cells, the more the relative cell surface area can be increased when compared with the same cell content while maintaining the strength of the article in an appropriate range. Therefore, the properties such as the liquid absorbability due to the porous structure can be expressed more satisfactorily.
For example, in rubber gloves, wet grip properties can be improved by imparting liquid absorbency with a porous surface. At that time, it is preferable that the latex foam as the forming material has a smaller average cell diameter because the average cell diameter of the formed rubber glove can be reduced and the liquid absorbability can be improved. Specifically, the average cell diameter is preferably 300 μm or less, and more preferably about 100 μm or less.

However, from the viewpoint of processability, strength of the article, etc., the bubble content of the latex foam is preferably as small as possible. Specifically, the bubble content is preferably 60% by volume or less, and more preferably about 40% by volume or less.
Methods for foaming latex are roughly classified into chemical foaming and physical foaming.
Among these, the chemical foaming method uses a foaming agent that generates gas by heating or chemical reaction. The said foaming agent can be made to foam by mix | blending the said foaming agent in latex, generating gas from a foaming agent by the said heating etc., and making it contain in latex.

In addition, as the physical foaming method, for example, a method of blowing air directly into the latex, or stirring and foaming the latex, that is, by mixing the lower latex (liquid) and the upper air from the liquid level by gas-liquid mixing, A method of including the air as bubbles in the latex is known.
In general, the physical foaming method has the advantage that the material cost can be reduced by the amount that does not require a foaming agent compared with the chemical foaming method, but it is difficult to control the average bubble diameter and bubble content of latex foam. Yes.

In order to solve this problem, various methods have been studied.
For example, in Patent Document 1, it has been studied to disperse the generated bubbles by stirring them using a stirrer equipped with a propeller blade as a stirring blade after bubbling gas into latex. In Patent Document 2, it is considered that the latex is stirred and foamed using a continuous mechanical foaming machine, a home mixer, or the like.

According to these methods, it is considered that the bubbles in the latex can be made finer to some extent than usual.
However, according to the inventor's study, these methods may not be able to reduce the bubbles to a sufficient level, for example, a level capable of imparting good liquid absorbency to the rubber glove as described above. In addition, the number of processes increases and the apparatus becomes complicated, and the time required for the work becomes long, resulting in a problem that the productivity of latex foam is lowered and the production cost is increased.

JP 2011-1662 A JP 2007-231428 A

  An object of the present invention is to provide a method for producing a latex foam, which can produce a latex foam with fine bubbles to a sufficient level, with a simpler apparatus, with fewer steps and a shorter working time with high productivity. There is.

In order to solve the above problems, the inventor has conducted various studies on a stirrer and a stirring tank used for foaming latex by stirring.
As a result, the inventors have found that the above problem can be solved by the following configuration.
As a stirring blade attached to the stirring shaft of the stirrer, a disc (disk) attached to the stirring shaft perpendicular to the direction of the central axis of the stirring shaft, and the stirring shaft in the circumferential direction of the disc A disk turbine blade provided with a plurality of flat blade bodies attached in a radial manner and orthogonal to the disk is used.
As the agitation tank, a batch-type open agitation tank having a cylindrical shape having a constant inner diameter D and having a central axis oriented in the vertical direction is used. The central axis of the agitation tank and the agitation shaft of the agitator The central axes are aligned with each other.

The ratio h of the distance h in the direction of the central axis between the liquid level of the latex before stirring and the disk constituting the disk turbine blade and the inner diameter D of the disk turbine blade attached to the stirring shaft When the stirring shaft is immersed in the latex so that / D is in a range satisfying 0.5 or more and 1.5 or less, the linear velocity at the radially outer tip of the blade body is 100 m / The latex is agitated by rotating it for more than a minute.
That is, when the agitator in which the disk turbine blade is attached to the agitation shaft is combined with the agitation tank and the latex is agitated in an immersion state satisfying the ratio h / D and the linear velocity , In addition to generating bubbles, the generated bubbles can be finely dispersed by a strong shearing force applied to the latex from the wing body.
Therefore, only by using the stirrer equipped with the disk turbine blade, the latex can be foamed more finely in a short time without the need for other processes, and the bubbles can be fined to a sufficient level. It becomes possible to produce the latex foam that has been made more productive than before.

Therefore, the present invention is a production method for producing a latex foam by foaming a latex of rubber or resin by stirring,
For the stirring, a stirrer having a stirring shaft and a stirring blade that rotates integrally with the stirring shaft is used, and the stirring blade is attached to the stirring shaft so as to be orthogonal to the direction of the central axis of the stirring shaft. And a disc turbine blade provided with a plurality of plate-like blades attached in a circumferential direction around the stirring shaft and perpendicular to the disc in the circumferential direction of the disc,
The latex is accommodated in a batch-type open type stirring tank having a cylindrical shape having a constant inner diameter D and having a central axis oriented vertically, and the central axis of the stirring tank and the stirring shaft of the stirrer Of the disk turbine blades attached to the stirring shaft in the direction of the central axis between the latex liquid level before stirring and the disk constituting the disk turbine blades. and distance h, the ratio h / D of the inner diameter D is 0.5 or more, the stirring shaft immersed state in the latex to be within a range that satisfies 1.5 or less, the diameter of the blade body A method for producing a latex foam, characterized in that the latex is stirred by rotating so that the linear velocity at the outer end in the direction is 100 m / min or more .

In the above manufacturing method of the present invention, the disk turbine blade, as the linear velocity of the radially outer tip of the blade body is 100 m / min or more, by stirring the latex by rotating the agitating shaft Further, by applying a stronger shearing force to the latex from the blade body of the disk turbine blade, it is possible to produce a latex foam in which bubbles are refined to a sufficient level more efficiently in a shorter time.

In the present invention, the ratio h / D that defines the amount of immersion of the disk turbine blade in the latex is limited to the above range for the following reason.
That is, when the ratio h / D is less than 0.5, the amount of immersion is not sufficient, and the disk turbine blade rotates at a position that is quite close to the liquid surface of the latex.
Therefore, there is a tendency that the degree of gas-liquid mixing by stirring tends to be too strong, the bubble content of the latex foam becomes excessively high, and the workability when processing into the shape of an article using the latex foam as a forming material is high decrease or, strength and the like of the article to be formed is you lowered.

On the other hand, when the ratio h / D exceeds 1.5, the amount of immersion becomes excessive, and the disk turbine blade rotates at a position considerably deeper than the liquid level of the latex.
Therefore, there is a tendency that the degree of gas-liquid mixing by stirring is too weak, latex foam bubble content becomes too low, the article not be obtained with excellent desired characteristics of the liquid absorbent and the like.

On the other hand, when the ratio h / D is within the range of 0.5 or more and 1.5 or less, the amount of immersion of the disk turbine blade in the latex and the degree of gas-liquid mixing by stirring are in an appropriate range. Can be maintained.
For this reason, the bubble content of the latex foam is set within a suitable range to further improve the workability, and further improve the properties such as strength and liquid absorbency of articles formed using the latex foam. It becomes possible to do.

  According to the present invention, there is provided a production method for producing a latex foam having fine bubbles to a sufficient level with a less number of steps and a shorter work time with a higher productivity using a simpler apparatus. Is possible.

It is a perspective view which shows the external appearance of an example of the disk turbine blade | wing which is the principal part of the stirrer used for the manufacturing method of the latex foam of this invention. It is sectional drawing which shows an example of the process of foaming latex using the disk turbine blade of the example of the said FIG. 1 among the manufacturing methods of the latex foam of this invention.

FIG. 1 is a perspective view showing an appearance of an example of a disk turbine blade, which is a main part of a stirrer used in the method for producing a latex foam of the present invention.
Referring to FIG. 1, a disk turbine blade 1 of this example is a circle that is detachably attached to a stirring shaft 2 of a stirrer (not shown) in a state perpendicular to the direction of the central axis L1 of the stirring shaft 2. A rectangular plate-like blade attached to the plate 3 in the circumferential direction of the disk 3 in this example, at six equal intervals, radially about the stirring shaft 2 and orthogonal to the disk 3 And a body 4.

  A cylindrical boss 6 having a through hole 5 through which the inner diameter of the disc 3 substantially coincides with the outer diameter of the stirring shaft 2 and through which the stirring shaft 2 is inserted is integrally provided. The disk 3, the boss 6 and the through hole 5 are provided concentrically with each other. The disc 3 is provided integrally with the boss 6 so as to be orthogonal to the direction of the central axis of the boss 6 and the through-hole 5 (which coincides with the central axis L1 of the stirring shaft 2 in the figure).

A screw hole 7 is passed through the boss 6 from the outer peripheral surface to the inner peripheral surface facing the through hole 5.
With the stirring shaft 2 inserted into the through hole 5 of the boss 6, a screw (not shown) is screwed into the screw hole 7 and tightened to tighten the disc 3 in the direction of the central axis L 1 of the stirring shaft 2. It can fix in the state made orthogonal to. Further, the disc 3 can be detached from the stirring shaft 2 by loosening the tightening of the screw.

Although the disk turbine blade 1 in the example shown in the figure includes six blade bodies 4, the number of blade bodies 4 can be arbitrarily set.
As the number of the blade bodies 4 increases, the effect of miniaturizing the bubbles due to the shearing force described above can be improved, but on the other hand, more power is required to rotate the disk turbine blade 1 at a predetermined rotational speed. become. Therefore, the number of the wing bodies 4 is preferably about 4 or more and 6 or less.

In addition, although the shape and dimensions of each wing body 4 are not particularly limited, the shape of the wing body 4 is rectangular as shown in the figure in view of improving the effect of applying shearing force to latex to refine bubbles. A flat plate shape is preferred.
Further, as the size of each side of the rectangular flat blade body 4 is increased, the effect of applying shear force to the latex to make the bubbles finer can be improved. However, on the other hand, the disk turbine blade 1 is rotated at a predetermined rotational speed. It takes a lot of power to rotate it. Therefore, the dimensions of both the vertical and horizontal sides are equivalent to twice the blade diameter d of the disk turbine blade 1 (from the central axis L1 to the radially outer tip 13 of the blade body 4 in the direction perpendicular to the central axis L1). ) Is preferably 0.2 times or more and 0.3 times or less.

FIG. 2 shows a latex foam production method according to the present invention, in which a stirrer in which the disk turbine blade of the example of FIG. 1 is attached to a stirring shaft 2 is used in combination with a batch type open stirring tank. It is sectional drawing which shows an example of the process of foaming.
Referring to FIG. 2, the agitation tank 8 has a cylindrical shape having a constant inner diameter D, and is disposed with its central axis L2 facing the vertical direction. The upper end of the stirring tank 8 in the vertical direction is an opening 9 and the lower end is closed as a bottom 10.

In the process of this example, first, a predetermined amount of latex 11 serving as a basis for latex foam is accommodated in the stirring tank 8.
Next, referring to FIG. 1 and FIG. 2, the central axis L2 of the stirring tank 8 and the central axis L1 of the stirring shaft 2 of the stirrer (not shown) are made to coincide with each other in the stirring tank 8. In this state, the disc turbine blade 1 attached to the tip of the stirring shaft 2 is immersed in the latex 11.

At this time, the distance h in the direction of the central axes L1 and L2 between the liquid surface 12 of the latex 11 before stirring and the central position in the thickness direction of the disk 3 constituting the disk turbine blade 1 is the above-described distance h. The amount of immersion of the disk turbine blade 1 in the latex 11 is set so as to be within a range satisfying 0.5 or more and 1.5 or less, expressed as a ratio h / D with the inner diameter D of the stirring tank 8. you.

If the ratio h / D is less than 0.5, the amount of immersion of the disk turbine blade 1 in the latex 11 is not sufficient, and the disk turbine blade 1 rotates at a position that is considerably close to the liquid surface 12 of the latex 11. It will be.
Therefore, there is a tendency that the degree of gas-liquid mixing by stirring tends to be too strong, the bubble content of the latex foam becomes excessively high, and the workability when processing into the shape of an article using the latex foam as a forming material is high decrease or, strength and the like of the article to be formed is you lowered.

On the other hand, when the ratio h / D exceeds 1.5, the amount of immersion becomes excessive, and the disk turbine blade 1 rotates at a position considerably deeper than the liquid surface 12 of the latex 11.
Therefore, there is a tendency that the degree of gas-liquid mixing by stirring is too weak, latex foam bubble content becomes too low, the article not be obtained with excellent desired characteristics of the liquid absorbent and the like.

On the other hand, when the ratio h / D is within the range of 0.5 or more and 1.5 or less, the amount of immersion of the disk turbine blade 1 in the latex 11 and the degree of gas-liquid mixing by stirring are appropriate. Can be maintained within a certain range.
For this reason, the bubble content of the latex foam is set within a suitable range to further improve the workability, and further improve the properties such as strength and liquid absorbency of articles formed using the latex foam. It becomes possible to do.

In consideration of further improving these effects, the ratio h / d is preferably 0.7 or more, and more preferably 1.0 or less, even within the above range.
The blade diameter d of the disk turbine blade 1 can be arbitrarily set according to the size of the stirring tank 8. However, in consideration of improving the stirring efficiency, the blade diameter d so that the ratio d / D between the blade diameter d and the inner diameter D of the stirring tank 8 is in the range of 0.3 to 0.4. It is preferable to set d and the inner diameter D of the stirring tank 8.

Further, in the example of the figure, only one disk turbine blade 1 is attached to the tip of the stirring shaft 2, but depending on the depth of the stirring tank 8, the amount of latex 11 accommodated in the stirring tank 8, etc. Two or more disk turbine blades 1 may be attached to one stirring shaft 2.
At that time, the immersion amount of the disk turbine blade 1 near the liquid surface 12 of the latex 11 attached to the upper side of the stirring shaft 2 near the liquid surface 12 of the latex 11 falls within the range of the ratio h / D. What is necessary is just to set so that it may satisfy.

Next, in the immersion state, a stirrer (not shown) is driven to rotate the stirring shaft 2, and the latex 11 is stirred by the disk turbine blade 1 attached to the tip of the stirring shaft 2.
Then, by mixing the latex 11 below the liquid surface 12 and the air above by the agitation, the air is included in the latex 11 as bubbles, and the bubbles are included in the blade body of the disk turbine blade 1. 4 can be finely dispersed by a strong shearing force applied to the latex 11.

Therefore, only by performing the agitation, it is possible to foam the latex more finely in a short time without the need for other processes. Can also be manufactured with high productivity.
The rotational speed of the agitation shaft 2 must be set to 100 m / min or more, expressed as the linear velocity of the radially outer tip 13 of the blade body 4 of the disk turbine blade 1, and particularly set to 250 m / min or more. It is preferable to do this.

By making the linear velocity within the above-mentioned range, the latex in which the blade 4 of the disk turbine blade 1 is given as strong a shearing force as possible to the latex 11, and the bubbles are refined to a sufficient level more efficiently in a shorter time. It becomes possible to produce a foam.
Note that the linear velocity is 500 m / min or less, particularly 450 m in the above range, considering that the degree of gas-liquid mixing by stirring becomes too strong and the bubble content of the latex foam is prevented from becoming excessively high. / Min or less is preferable.

The stirring time, temperature, and the like can be arbitrarily set according to the type and viscosity of the latex to be stirred.
Among these, the stirring temperature (latex liquid temperature) is an efficient production of latex foam by, for example, foaming the latex well while preventing the rubber in the latex from being completely vulcanized during stirring. In consideration of such things, it is preferably about room temperature (5-35 ° C.).

Further, the stirring time is preferably 30 minutes or more, and preferably 2 hours or less in consideration of producing a latex foam with fine bubbles to a sufficient level as efficiently as possible.
As the latex used as the basis of the latex foam produced by the above production method, any of various latexes that can be used as a material for forming various articles, including various rubbers and resins, can be used.

Examples of the rubber latex include natural rubber latex, deproteinized natural rubber latex, nitrile rubber (acrylonitrile-butadiene rubber) latex, styrene-butadiene rubber latex, and chloroprene rubber latex. It is done.
In addition to the vulcanizing agent (such as sulfur) for vulcanizing the rubber, the rubber latex includes a vulcanization accelerator, a vulcanization promoting aid (such as titanium oxide), an anti-aging agent, a filler, and a dispersant. Various additives such as a stabilizer and a surfactant may be blended.

Further, a foaming agent, a microcapsule, a foaming agent and the like can be blended, and the latex can be foamed by the stirring, that is, the physical foaming method, and can be foamed by the chemical foaming method using the foaming agent or the like.
Examples of the resin latex include one or more emulsions (latex) of a resin that can be emulsified (latexed), such as a vinyl chloride resin, a urethane resin, and an acrylic resin.

Various additives such as anti-aging agents, fillers, dispersants, stabilizers, surfactants and the like may be further added to the resin latex.
In addition, foaming agent, microcapsule, foaming agent, etc. are blended in the same way as rubber latex, and the latex is foamed by the stirring, that is, the physical foaming method, and foamed by the chemical foaming method using the foaming agent. You can also.

  According to the present invention, a latex foam whose bubbles are refined to a sufficient level only by stirring the latex of rubber or resin using the stirrer provided with the disk turbine blade as described above can be obtained in a shorter working time. This makes it possible to manufacture with good productivity.

Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the configuration of the present invention is not limited to these. In addition, manufacture of the latex foam of an Example and a comparative example was implemented in 23 degreeC environment.
<Example 1>
(Latex preparation)
For natural rubber latex, 0.5 parts by mass of ammonia casein, 1 part by mass of potassium oleate, 1 part by mass of potassium hydroxide, 1 part by mass of sulfur, and dibutyl per 100 parts by mass of rubber (solid content) in the natural rubber latex 1 part by mass of zinc carbamate, 0.5 part by mass of zinc oxide, and 3 parts by mass of titanium oxide were blended to prepare a latex as a raw material for latex foam. In addition, what was supplied in aqueous solution among the said each component described the quantity of the active ingredient in it.

(Stirring process)
As shown in FIG. 2, the stirring tank 8 for storing the latex has a cylindrical shape with an inner diameter D of 140 cm, and its central axis L2 is arranged in the vertical direction, and the upper end in the vertical direction is open. 9 and having a capacity of 500 L with the lower end closed as the bottom 10 was used.
As the stirring blade, as shown in FIGS. 1 and 2, a disc 3 attached to the stirring shaft 2 of a stirrer (not shown) perpendicular to the direction of the central axis L1 of the stirring shaft 2; In the circumferential direction of the disc 3, there are provided six rectangular flat plate-like wing bodies 4 that are radially centered on the stirring shaft 2 and perpendicular to the disc 3, and the blade diameter d is 50 cm. The disc turbine blade 1 is used.

The ratio d / D between the blade diameter d and the inner diameter D of 8 of the stirring vessel was 0.36.
A central axis between the disk turbine blade 1 attached to the tip of the stirring shaft 2 and the liquid surface 12 of the latex 11 before stirring from the central position in the thickness direction of the disk 3 constituting the disk turbine blade 1. It was immersed in the latex 11 so that the distance h in the direction of L1 and L2 was 120 cm.

The ratio h / D between the distance h and the inner diameter D of 8 in the stirring vessel was 0.86.
Next, the stirrer was driven, the stirring shaft 2 was rotated at a rotation speed of 200 rpm, and the mixture was stirred for 1 hour to foam the latex, thereby producing a latex foam.
The linear velocity of the radial outer tip 13 of the blade body 4 of the disk turbine blade 1 during the stirring was 314 m / min.

< Comparative Example 1 >
A latex foam was produced in the same manner as in Example 1 except that the rotation speed of the stirring shaft 2 was 60 rpm, and the linear velocity of the radial outer tip 13 of the blade body 4 of the disk turbine blade 1 was 94 m / min.
The ratio d / D was 0.36 as in Example 1, and the ratio h / D was also 0.86 as in Example 1.

< Comparative Example 2 >
The distance h in the direction of the central axes L1 and L2 between the disk turbine blade 1 from the liquid level 12 of the latex 11 before stirring and the center position in the thickness direction of the disk 3 constituting the disk turbine blade 1 is A latex foam was produced in the same manner as in Example 1 except that it was immersed in the latex 11 so as to be 60 cm.

The ratio d / D was 0.36 as in Example 1, and the ratio h / D was 0.43.
< Example 2 >
The distance h in the direction of the central axes L1 and L2 between the disk turbine blade 1 from the liquid level 12 of the latex 11 before stirring and the center position in the thickness direction of the disk 3 constituting the disk turbine blade 1 is A latex foam was produced in the same manner as in Example 1 except that it was immersed in the latex 11 so as to be 210 cm.

The ratio d / D was 0.36 as in Example 1, and the ratio h / D was 1.5.
< Comparative Example 3 >
Instead of the disk turbine blade 1, three blades having a substantially elliptical shape and twisted are fixed to a cylindrical boss by being inclined with respect to the direction of the central axis L1, and the blade diameter d is 50 cm. The three-blade propeller blade was used.

The distance h in the direction of the central axes L1 and L2 from the liquid surface 12 of the latex 11 before stirring to the bosses of the propeller blades to the attachment portions of the blades is 60 cm. It was immersed in latex 11.
The ratio d / D was 0.36 as in Example 1, and the ratio h / D was 0.43 as in Comparative Example 2 .

In this state, the stirrer was driven, the stirring shaft 2 was rotated at a rotation speed of 200 rpm, and stirred for 1 hour to foam the latex, thereby producing a latex foam.
The linear velocity at the radially outer tip of the blade body of the propeller blade during the stirring was 314 m / min.
< Comparative example 4 >
Instead of the disc turbine blade 1, four blades having a blade diameter d of 50 cm, in which four blades having a rectangular flat plate shape are fixed to a cylindrical boss while being inclined with respect to the direction of the central axis L <b> 1. The paddle wing was used.

The distance h in the direction of the central axes L1 and L2 between the liquid surface 12 of the latex 11 before stirring and the center position of the boss of the paddle blade in the direction of the central axes L1 and L2 It was immersed in latex 11 so as to be 60 cm.
The ratio d / D was 0.36 as in Example 1, and the ratio h / D was 0.43 as in Comparative Example 2 .

In this state, the stirrer was driven, the stirring shaft 2 was rotated at a rotation speed of 200 rpm, and stirred for 1 hour to foam the latex, thereby producing a latex foam.
The linear velocity at the radially outer tip of the blade body of the paddle blade during stirring was 314 m / min.
<Measurement of latex foam properties>
The average cell diameter and cell content of the latex foam produced in each of the above Examples and Comparative Examples were measured by the following methods. All measurements were performed in an environment of 23 ° C.

(Average bubble diameter)
A small amount of the manufactured latex foam was sampled on a petri dish, an image was taken using a digital microscope, and image analysis was performed. That is, 50 bubbles were arbitrarily selected from the photographed image, and the average value was calculated from the result of measuring the diameter of each bubble in the two-point distance measurement mode to obtain the average bubble diameter (μm).

(Bubble content)
The produced latex foam was weighed with a cylinder to have a volume of 100 ml, and its mass was measured to determine the apparent specific gravity of the latex foam.
The bubble content (% by volume) was calculated from the apparent specific gravity and the true specific gravity of the latex that was the basis of the latex foam.

  The results are shown in Table 1.

From the results of Examples 1 and 2 and Comparative Examples 3 and 4 in Table 1, by using a disk turbine blade as a stirring blade, the average cell diameter of the latex foam produced is larger than when other stirring blades are used. It was found that a latex foam having fine bubbles to a sufficient level can be produced with high productivity in a shorter working time without requiring a step of dispersing the bubbles.

From the results of Examples 1 and 2 and Comparative Example 1 , considering that the average bubble diameter should be as small as possible with the same stirring time, the linear velocity of the disk turbine blade at the radially outer tip of the blade body is 100 m / It has been found that the agitation shaft needs to be rotated so as to be more than a minute.
Further, from the results of Examples 1 and 2 and Comparative Example 2 , considering the suppression of the bubble content, the amount of immersion of the disk turbine blade in the latex is h / D of 0.5 or more and 1.5 or less. It was found that it was necessary to set so that

DESCRIPTION OF SYMBOLS 1 Disc turbine blade 2 Stirring shaft 3 Disc 4 Blade body 5 Through-hole 6 Boss 7 Screw hole 8 Stirrer tank 9 Opening 10 Bottom part 11 Latex 12 Liquid surface 13 Radially outward tip D Inner diameter d Blade diameter h Distance L1, L2 center axis

Claims (1)

A production method for producing latex foam by foaming a latex of rubber or resin by stirring,
For the stirring, a stirrer having a stirring shaft and a stirring blade that rotates integrally with the stirring shaft is used, and the stirring blade is attached to the stirring shaft so as to be orthogonal to the direction of the central axis of the stirring shaft. And a disc turbine blade provided with a plurality of plate-like blades attached in a circumferential direction around the stirring shaft and perpendicular to the disc in the circumferential direction of the disc,
The latex is accommodated in a batch-type open type stirring tank having a cylindrical shape having a constant inner diameter D and having a central axis oriented vertically, and the central axis of the stirring tank and the stirring shaft of the stirrer Of the disk turbine blades attached to the stirring shaft in the direction of the central axis between the latex liquid level before stirring and the disk constituting the disk turbine blades. and distance h, the ratio h / D of the inner diameter D is 0.5 or more, the stirring shaft immersed state in the latex to be within a range that satisfies 1.5 or less, the diameter of the blade body A method for producing a latex foam, characterized in that the latex is stirred by rotating so that the linear velocity at the outer end in the direction is 100 m / min or more .

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