JP2017172078A - Manufacturing method for glove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for manufacturing polyurethane gloves which are hardly ruptured even if being a non-support type owing to hardly generating a crack on a membrane, by an immersion method using an immersion liquid having a water-based polyurethane dispersion as a starting material.SOLUTION: As for an immersion liquid to be used for an immersion method, an immersion liquid which is mixed with a water-based polyurethane dispersion and ethylene glycol is used. A mixing ratio of the ethylene glycol is preferably 1 pt.mass or more per 100 pts.mass of solid in the polyurethane dispersion, and preferably 10 pts.mass or less.SELECTED DRAWING: None

Description

  The present invention relates to a method for producing a glove comprising a polyurethane film.

Gloves for household use are generally manufactured by an immersion method using an immersion liquid starting from, for example, rubber latex or resin dispersion, and the main products of products using such an immersion method are One can say.
In the dipping method, the hand mold corresponding to the three-dimensional shape of the glove is first dipped in a coagulant solution (coagulation liquid) such as calcium nitrate and then dried to adhere the coagulant to the surface of the hand mold (pretreatment Process).

Next, by immersing the hand mold in an immersion liquid and pulling it up, a gel containing rubber or resin containing water is generated in the vicinity of the surface by the action of a coagulant previously attached to the surface of the hand mold. And it is made to adhere to the said surface (immersion process).
Next, by heating the hand mold in an oven or the like to remove moisture from the gel, after forming a dried and solidified continuous film on the surface of the hand mold (drying process), the film is removed from the hand mold. Demold to produce gloves (demolding process).

However, the conventional gloves made of the above-mentioned dipping method and made of rubber such as natural rubber or resin such as vinyl chloride have almost no moisture permeability, so the inside is easily stuffy, and the user feels uncomfortable. Depending on the situation, there may be a problem that the hand and the glove adhere to each other due to sweat and the detachability or the workability when the glove is worn may be impaired.
Therefore, instead of conventional rubber and resin, it is possible to produce gloves that are less stuffy and less likely to cause discomfort by using polyurethane that can form a film with excellent wear resistance and flexibility and excellent moisture permeability. Conceivable.

In particular, it is desirable to produce a polyurethane glove by an immersion method as in the prior art, using an immersion liquid that uses an aqueous polyurethane dispersion containing no organic solvent as a starting material.
However, at present, a technique for manufacturing a non-support type glove formed only by a polyurethane film by a dipping method has not been sufficiently established.
For example, support type gloves in which polyurethane is coated by a dipping method on a hand made of cotton or nylon have been put to practical use (Patent Documents 1, 2 etc.), or non-support type gloves made of a porous film such as rubber. In addition, the present situation is that a two-layered glove coated with a thin polyurethane film has been studied (Patent Document 3, etc.).

  This is because the polyurethane film in the middle of drying that adheres to the surface of the hand mold is prone to cracks (gel cracks), and the cracked film does not have sufficient tensile strength after drying. This is because a non-support type glove made of a single body is relatively easy to break when pulled.

JP 2008-38303 A Japanese Patent No. 3784268 International Publication WO2013 / 054721 A1

  The object of the present invention is to immerse a polyurethane glove that is difficult to break even if it is a non-support type because it is difficult to crack the film, and an immersion method using an immersion liquid starting from an aqueous polyurethane dispersion. It is in providing the manufacturing method for manufacturing by.

  The present invention includes a step of immersing the hand mold corresponding to the three-dimensional shape of the glove in an immersion liquid and then pulling it up, attaching the immersion liquid to the hand mold, and further drying to form a film that becomes a glove, The immersion liquid is a method for manufacturing a glove using an aqueous polyurethane dispersion and an immersion liquid containing ethylene glycol.

  According to the present invention, since the film is less likely to crack, even if it is a non-support type, the polyurethane glove is not easily broken, and an immersion method using an immersion liquid starting from an aqueous polyurethane dispersion is used. Can be manufactured.

As described above, in the present invention, a hand mold corresponding to a three-dimensional shape of a glove is dipped in an immersion liquid and then pulled up, and the immersion liquid is attached to the hand mold and further dried to form a film that becomes a glove. A method of manufacturing a glove using a water-based polyurethane dispersion and an immersion liquid containing ethylene glycol as the immersion liquid.
According to the manufacturing method of the present invention, it is possible to manufacture a polyurethane glove that is not easily broken even if it is a non-support type.

In other words, using a dipping solution containing an aqueous polyurethane dispersion, the film formed by the dipping method is prone to cracking because the drying speed of the gel adhering to the surface of the hand mold is locally increased. One reason for this is that the gel shrinkage does not proceed uniformly throughout the film and tends to be non-uniform.
On the other hand, when ethylene glycol is blended in the immersion liquid, the ethylene glycol is a component that functions as a wetting agent, an anti-drying agent, etc., so that the local and non-uniform gel drying and shrinkage are suppressed, The shrinkage of the gel can be made substantially uniform throughout the film, and cracks can be prevented from occurring in the film.

Therefore, according to the manufacturing method of the present invention, it is possible to manufacture a polyurethane glove that is not easily broken even if it is a non-support type.
<ethylene glycol>
The blending ratio of ethylene glycol is preferably 1 part by mass or more and preferably 10 parts by mass or less per 100 parts by mass of the solid content in the polyurethane dispersion.

If the blending ratio of ethylene glycol is less than this range, the effect described above by blending the ethylene glycol, that is, the effect of suppressing local and non-uniform gel shrinkage cannot be sufficiently obtained, so that a crack occurs in the film. May be easier.
On the other hand, when the blending ratio of ethylene glycol exceeds the above range, the drying speed of the gel is excessively slow, so that the immersion liquid is liable to drip when the hand mold is pulled up from the immersion liquid and dried. If any of them occurs, the thickness of the gloves may be partially uneven.

On the other hand, by making the blending ratio of ethylene glycol within the above range, while suppressing dripping of the immersion liquid as much as possible, the gel contraction at the time of drying is almost uniformized throughout the film, and the film is cracked. Can be more effectively suppressed.
<Water-based polyurethane dispersion>
As the water-based polyurethane dispersion, for example, various dispersions in which polyurethane, which is a reaction product of various polyols such as polyester, polyether and polycarbonate, and polyisocyanate are dispersed in water can be used. .

In particular, from the viewpoint of improving the moisture permeability of gloves, a polyether-based polyurethane dispersion is preferable.
In addition, it is preferable to select and use an aqueous polyurethane dispersion having a surface tension of 39 N / m or more and 55 N / m or less.
The immersion liquid prepared using a water-based polyurethane dispersion having a surface tension of 39 N / m or more is particularly excellent in wettability to the surface of a ceramic hand mold and easily spreads evenly on the surface of the hand mold. .

The polyurethane particles contained in the immersion liquid can be smoothly solidified on the surface of the hand mold. The reason for this is not clear, but polyurethane dispersions with surface tensions below the above range contain many components that lower the surface tension, such as fatty acid functional groups such as carboxylates, and these components protect polyurethane particles. To inhibit coagulation.
In contrast, a polyurethane dispersion having a surface tension of 39 N / m or more is considered to be easily solidified on the surface of the hand mold because the ratio of the above components is small.

However, if the surface tension is too high, the polyurethane particles are excessively coagulated, and local and non-uniform drying and shrinkage of the gel during drying is likely to occur.
Therefore, conventionally, the surface tension of the polyurethane dispersion is preferably about 45 N / m or less, but in the present invention, the shrinkage of the gel at the time of drying can be made almost uniform throughout the film by the function of ethylene glycol. Polyurethane dispersions having a surface tension of 55 N / m or less can be used.

That is, by preparing an immersion liquid using an aqueous polyurethane dispersion having a surface tension of 55 N / m or less in combination with ethylene glycol, local and non-uniform drying and shrinkage of the gel during drying is suppressed, and cracks are generated. Can be suppressed.
Therefore, by selecting and using an aqueous polyurethane dispersion having a surface tension of 39 N / m or more and 55 N / m or less, the continuity and uniformity of the film can be improved and the tensile strength of the glove can be further improved. .

  Such a water-based polyurethane dispersion is not limited to this, but, for example, FCS725 (surface tension: 40.9 N / m), WLS-210 (surface tension: 40) in the Hydran (registered trademark) series manufactured by DIC Corporation. .8 N / m), WLS-208 (surface tension: 52.6 N / m), Takelac (registered trademark) W6110 (surface tension: 42.3 N / m) manufactured by Mitsui Chemicals, Inc., SANNCURE (manufactured by Lubrizol) Registered trademark) 12929 (surface tension: 43.4 N / m) and the like.

<Carbodiimide compound>
When a carbodiimide compound is blended in the immersion liquid, the carbodiimide compound functions as a cross-linking agent for polyurethane, and while maintaining the good moisture permeability of the film made of the polyurethane as it is, the tensile strength of the film and thus the glove is further increased. It can be further improved.
Further, even when the immersion liquid is prepared and stored for several days and used for manufacturing gloves, it is possible to suppress as much as possible the decrease in the tensile strength, elongation, flexibility, etc. of the gloves as compared to immediately after the preparation.

As the carbodiimide compound, various compounds that contain a carbodiimide group (—N═C═N—) in the molecule and can function as a crosslinking agent for polyurethane can be used.
However, as the carbodiimide compound, a compound having a chemical formula amount (hereinafter sometimes abbreviated as “NCN equivalent”) per mole of the carbodiimide group is 620 or less, particularly 600 or less.

The lower limit of the NCN equivalent is not particularly limited, but in consideration of the stability and handleability of the carbodiimide compound, the affinity and compatibility with polyurethane, the dispersion stability in the immersion liquid, and the like, it binds to both ends of the carbodiimide group. It is desirable that the organic group has an appropriate size, and the NCN equivalent is preferably 300 or more, particularly 350 or more.
The carbodiimide compound is not limited to this, but, for example, V-04 [NCN equivalent: 335, active ingredient] supplied in the form of an aqueous solution among carbodilite (registered trademark) series manufactured by Nisshinbo Chemical Co., Ltd. Concentration: 40%], V-02-L2 [NCN equivalent: 385, active ingredient concentration: 40%], V-10 [NCN equivalent: 410, active ingredient concentration: 40%], SV-02 [NCN equivalent: 430 , Active ingredient concentration: 40%], SW-12G [NCN equivalent: 465, active ingredient concentration: 40%], V-02 [NCN equivalent: 590, active ingredient concentration: 40%], or soap-free emulsion E-03A [NCN equivalent: 365, active ingredient concentration: 40%], E-02 [NCN equivalent: 445, active ingredient concentration: 40%] It includes one or more of.

The blending ratio of the carbodiimide compound is preferably 2 parts by mass or more per 100 parts by mass of the solid content in the polyurethane dispersion, and preferably 10 parts by mass or less.
If the blending ratio of the carbodiimide compound is less than this range, the effects described above by blending the carbodiimide compound, that is, the effect of improving the tensile strength of the glove by crosslinking polyurethane may not be sufficiently obtained.

On the other hand, when the compounding ratio of the carbodiimide compound exceeds the above range, the flexibility and elongation of the glove are reduced, and the workability when attaching / detaching the glove and working with the glove is reduced. There is a risk.
In addition, when the immersion liquid is prepared and stored for several days and then used for the production of gloves, the tensile strength, elongation, flexibility, etc. of the glove may be greatly reduced as compared to immediately after the preparation.

On the other hand, the tensile strength of a glove can be improved rather than the present condition, maintaining favorable softness | flexibility and elongation by making the mixture ratio of a carbodiimide compound into said range. Moreover, even if the immersion liquid is prepared and used after being stored for several days, it is possible to suppress a decrease in the tensile strength, elongation, flexibility, and the like of the glove compared to immediately after the preparation.
In consideration of further improving this effect, the blending ratio of the carbodiimide compound is 8 parts by mass or less, particularly 6 parts by mass or less, per 100 parts by mass of the solid content in the polyurethane dispersion even in the above range. Is preferred.

  In addition, when using what is supplied in the state of aqueous solution or emulsion as above-mentioned as a carbodiimide compound, the mass part of the carbodiimide compound itself as an active ingredient contained in the said aqueous solution or emulsion is in polyurethane dispersion. What is necessary is just to set the mixture ratio of the said aqueous solution and emulsion so that it may become the range mentioned above with respect to 100 mass parts of solid content.

<Immersion liquid>
The immersion liquid can be constructed in the same manner as in the prior art except that it contains the aqueous polyurethane dispersion, ethylene glycol, and, if necessary, a carbodiimide compound.
In other words, the polyurethane dispersion is blended with ethylene glycol and, if necessary, a carbodiimide compound, and if necessary, an anti-aging agent, a filler, a heat stabilizer, a crosslinking agent, a hydrolysis stabilizer, an antifoaming agent, and a plasticizer. The immersion liquid is prepared by blending various additives such as a colorant, a dispersion stabilizer, and a thickener in a predetermined ratio.

(Anti-aging agent)
Among the above, as the anti-aging agent, various anti-aging agents such as phenol and amine can be used.
In particular, a phenolic anti-aging agent is preferable. When a phenolic anti-aging agent is blended, the tensile strength of the glove can be improved by suppressing deterioration of the polyurethane due to heat during production.

Moreover, even if it uses it after preparing immersion liquid and storing for several days, it can suppress that the tensile strength of a glove, elongation, a softness | flexibility, etc. fall compared with immediately after preparation.
The blending ratio of the phenolic anti-aging agent is preferably 0.5 parts by mass or more, preferably 2 parts by mass or less, particularly preferably 1.5 parts by mass or less, per 100 parts by mass of the solid content in the polyurethane dispersion. .

When the blending ratio of the phenolic anti-aging agent is less than this range, there is a possibility that the above effect due to the blending of the phenolic anti-aging agent cannot be sufficiently obtained.
On the other hand, if the blending ratio of the phenolic anti-aging agent exceeds the above range, not only the effect is not obtained, but also the flexibility and elongation of the glove may be lowered.
(Other ingredients)
Examples of the filler include one or more of kaolin clay, hard clay, calcium carbonate, titanium oxide and the like.

  A thickener imparts an appropriate viscosity to the immersion liquid and adheres well to the surface of the hand mold.For example, when foaming the immersion liquid to make the glove have a porous structure, the viscosity of the immersion liquid is increased. Such a thickener includes, for example, a water-soluble polymer such as polyacrylic acid. The thickener is preferably omitted in order to prevent the viscosity of the immersion liquid from becoming too high and to produce a non-uniform glove, but when blended, depending on the viscosity required for the immersion liquid What is necessary is just to set the mixture ratio suitably.

  The dispersion stabilizer is blended in order to satisfactorily disperse solid and water-insoluble components such as an anti-aging agent and a filler among the additives in the immersion liquid. As the dispersion stabilizer, For example, 1 type (s) or 2 or more types, such as anionic surfactant, are mentioned. The blending ratio of the dispersion stabilizer is preferably 0.3 parts by mass or more and preferably 1 part by mass or less per 100 parts by mass of the solid content in the polyurethane dispersion.

The water-insoluble additive is preferably blended in the immersion liquid after being dispersed in water using a ball mill or the like in the presence of the dispersion stabilizer.
<Manufacture of gloves>
In the manufacturing method of the present invention, first, a hand mold corresponding to the three-dimensional shape of a glove, for example, made of earthenware or metal is prepared.

Next, the hand mold preliminarily heated to 40 to 80 ° C. is immersed in the coagulating liquid, and then pulled up and dried.
As the coagulating liquid, various coagulating liquids for the dipping method can be used. Examples of the coagulation liquid include an aqueous solution of a coagulant such as calcium nitrate and calcium chloride, a methanol solution, and an ethanol solution.

Although the concentration of the coagulant in the coagulation liquid can be arbitrarily set, it is preferably 20% by mass or less.
When a relatively thin coagulating liquid having a concentration of the coagulant of 20% by mass or less is used, the coagulation of the polyurethane particles on the surface of the hand mold can be made as slow as possible to improve the uniformity of the arrangement of the polyurethane particles, and during the drying process The occurrence of cracks in the film can be suppressed even better.

Next, the hand mold treated with the coagulating liquid is dipped in the immersion liquid containing the components described above for a certain period of time, and then pulled up to attach the immersion liquid to the surface of the hand mold.
Then, the raised hand mold is heated to dry the immersion liquid. When a carbodiimide compound is included, the polyurethane is crosslinked to form a film, and then the film is demolded.
Alternatively, the immersion liquid may be once dried at room temperature, and then heated together with the hand mold to form a film by cross-linking the polyurethane to remove the mold.

<gloves>
The glove manufactured by the manufacturing method of the present invention may have a porous structure by foaming the immersion liquid, or may have a non-porous structure without foaming. In view of improving the tensile strength and the like, it is preferable to have a non-porous structure.
The glove may have a single layer structure made of a single polyurethane film or may have a laminated structure with one or more other layers. Examples of other layers that may be laminated include a porous or non-porous structure layer made of rubber or resin, a layer of a hand that constitutes a so-called support type glove, and the like.

However, in consideration of productivity, price, and ease of use and excellent workability, a so-called non-support type glove having a non-porous structure and a single layer structure is preferable.
The thickness of the non-supporting glove can be arbitrarily set according to the use of the glove. For example, the thickness of an ultra-thin glove suitable for fine work is 0.16 mm or more, especially 0.17 mm or more, especially 0.19 mm in consideration of imparting sufficient strength and improving workability and fit. It is preferable that it is above, and it is preferable that it is 0.55 mm or less.

Moreover, you may plant a pile on the inner surface of a glove. The flocking method may be the same as in the past.
For example, a pile is sprayed on the pre-drying dipping solution attached to the hand mold, heated with the mold to dry the dipping solution, forming a film and fixing the pile (flocking), then turning the film over It may be possible to remove the mold.
Further, for example, the hand mold in a state where a film to be a glove is formed first is immersed in an immersion liquid that is the basis of the adhesive layer, and the immersion liquid is attached to the surface of the glove, and a pile is formed thereon. After spraying, the entire mold may be heated to dry the immersion liquid to form an adhesive layer, fix the pile (planting), and remove the mold while turning over the film.

The latter adhesive layer preferably has a continuous porous structure in order to ensure the moisture permeability of the gloves. For this purpose, for example, an adhesive such as natural rubber, nitrile rubber, urethane rubber, chloroprene rubber or the like is used as the starting material. It is preferable that the layer immersion liquid is foamed in advance.
Examples of the pile include piles of cotton, nylon, rayon and the like, and in particular, a rayon-type pile is preferable because of good touch.

<Example 1>
(Preparation of immersion liquid)
Aqueous polyurethane dispersion [Hydran FCS725 manufactured by DIC Corporation, surface tension: 40.9 N / m] and an aqueous solution of ethylene glycol and carbodiimide compound [Carbodilite V- manufactured by Nisshinbo Chemical Co., Ltd.] 02, NCN equivalent: 590, active ingredient concentration: 40%], and titanium oxide were blended to prepare an immersion liquid.

In the above immersion liquid, the blending ratio per 100 parts by mass of the solid content in the polyurethane dispersion is 1 part by mass of ethylene glycol, 3 parts by mass of the carbodiimide compound as an active ingredient contained in the aqueous solution, and 1.5% of titanium oxide. Part by mass.
(Manufacture of gloves)
As a hand mold, a ceramic hand mold corresponding to the three-dimensional shape of the glove was prepared.

This hand mold was first immersed in a 25% by mass calcium nitrate aqueous solution as a coagulation liquid, pulled up, heated to 60 ° C. and dried.
Next, the immersion liquid was attached to the surface by pulling up after being immersed in the immersion liquid. Then, the raised hand mold was heated at 110 ° C. for 30 minutes to dry the immersion liquid, and the polyurethane was subjected to a crosslinking reaction. After further cooling, the mold was removed to produce a glove.

<Examples 2 to 5>
The blending ratio of ethylene glycol is 0.5 parts by mass (Example 2), 3 parts by mass (Example 3), 10 parts by mass (Example 4) and 15 parts by mass per 100 parts by mass of the solid content in the polyurethane dispersion. A glove was produced in the same manner as in Example 1 except that (Example 4) was used.
<Comparative example 1>
A glove was produced in the same manner as in Example 1 except that ethylene glycol was not blended.

<Number of cracks>
The manufacture of the gloves of each Example and Comparative Example was carried out 10 times, and the number of gloves with cracks was counted among the 10 gloves manufactured. And the quality of the crack generation was evaluated according to the following criteria.
○: The number of generated sheets was less than one.
Δ: The number of generated sheets was 1 or more and less than 5.

X: The number of generated sheets was 5 or more.
<Presence or absence of dripping>
The manufacture of the gloves of each Example and Comparative Example was performed 10 times, and the number of gloves in which dripping occurred was counted among the 10 gloves manufactured. And the presence or absence of dripping was evaluated according to the following criteria.
○: The number of generated sheets was less than one.

Δ: The number of generated sheets was 1 or more and 5 or less.
X: The number of generated sheets was 5 or more.
The results are shown in Table 1.

From the results of Examples 1 to 5 and Comparative Example 1 in Table 1, by adding ethylene glycol to the immersion liquid containing an aqueous polyurethane dispersion, it is possible to suppress the occurrence of cracks in the film, and as a non-support type It has been found that it is possible to produce gloves that are not easily broken or easily broken.
Further, from the results of Examples 1 to 5, considering that the above effect is further improved while suppressing the dripping of the immersion liquid, the blending ratio of ethylene glycol is about 100 parts by mass of the solid content in the polyurethane dispersion. It was found that the amount was preferably 1 part by mass or more, and preferably 10 parts by mass or less.

Claims (3)

  A step of immersing the hand mold corresponding to the three-dimensional shape of the glove in an immersion liquid and then pulling it up, attaching the immersion liquid to the hand mold, and further drying to form a film that becomes a glove, Is a method for producing a glove using an aqueous polyurethane dispersion and an immersion liquid containing ethylene glycol.   The method for producing a glove according to claim 1, wherein the blending ratio of the ethylene glycol is 1 part by mass or more and 10 parts by mass or less per 100 parts by mass of the solid content in the polyurethane dispersion.   The manufacturing method of the glove of Claim 1 or 2 which uses what further contains a carbodiimide compound as said immersion liquid.