JP4918353B2 - Articles containing water-soluble polyureaurethane dispersion - Google Patents

Description

  Using polyurethane particles dispersed in water reduces the chances of chemical and biological allergic reactions to the skin compared to gloves made of other materials, improving resistance to fracture and tearing Products can be made.

(Cross-reference of related applications)
This application is a benefit of US Provisional Patent Application No. 60 / 448,971, filed February 20, 2003, and US Provisional Patent Application No. 60 / 423,617, filed November 4, 2002. Each of which is incorporated by reference herein in its entirety for all purposes.

  The production of elastomeric materials is well described in the art (see, for example, (NPL 1)). Elastomeric materials, specifically spandex, contain the following repeating urethane linkages:

Many of the urethane polymers currently used in the production of spandex are prepared by reacting a hydroxy-terminated polyether or polyester with a diisocyanate in a molar ratio of about 1: 1.4 to 1: 2.5, followed by The isocyanate-terminated prepolymer obtained above is reacted with one or more diamines to produce a high molecular weight urethane polymer. A small amount of monofunctional amine can be introduced to control the polymer molecular weight. By changing the particular polyester or polyether glycol, diisocyanate, diamine, and monoamine used, the mechanical properties can be influenced. Further, it can be modified by changing the molecular weight of glycol and changing the molar ratio of glycol-diisocyanate.

  Long chain urethane polymer molecules in spandex are substantially linear block copolymers in which relatively long blocks with weak intermolecular interactions are connected by shorter blocks with strong interactions. This weakly interacting block, commonly referred to as the soft segment, is from the polyether or polyester glycol component, while the strongly interacting block, referred to as the hard segment, results from the reaction of the diisocyanate and the chain extender. The chain extension reaction is usually a coupling reaction between an isocyanate and a bifunctional amine, and forms a urea bond. Thus, the polymer obtained by combining hard and soft segments is known as polyureaurethane.

  It is known that polyisocyanate polymers can be used to prepare water-soluble polyurethane dispersions. Polyurethane dispersions usually comprise organic diisocyanates or polyisocyanates and organic compounds having two or more active hydrogen atoms such as polyalkylene ether glycols, poly (alkylene ether) glycols, alkyd resins, polyesters, and polyester amides. The reaction product is often prepared by chain extension using a small amount of organic solvent. Diisocyanate is used in stoichiometric excess to render the end group of the reaction product, also called polyurethane / urea prepolymer, as isocyanate. Examples of polyurethane prepolymer preparations include, among others, US Patent Publication (Patent Document 1), US Patent Publication (Patent Document 2), US Patent Publication (Patent Document 3), US Patent Publication (Patent Document 4), and US Patent Publication ( Patent Document 5).

  Polyurethane dispersions are known as coatings and bond layers in US Patent Publication (Patent Document 6); flexible solvent barriers in US Patent Publication (Patent Document 7); adhesives in US Patent Publication (Patent Document 8). The US Patent Publication (Patent Document 9) reports that it is useful for preparing a variety of materials such as films. Films, strictly speaking, dipping methods for making films can be part of a method for making multiple articles. Examples of film applications include gloves, organ bags, condoms, ostomy bags, and the like. Although it is known that such applications can be made with polyurethane dispersions, ordinary polyurethane dispersions have insufficient physical or handling properties to make them preferred materials for such applications. Sometimes it turns out. Also, the use of certain relatively high boiling solvents such as N-methyl-2-pyrrolidone can have adverse effects in some applications.

  Polyurethane is the reaction product of polyalcohol and polyisocyanate. In general, the polyisocyanates used to prepare water-soluble polyurethane dispersions are aliphatic isocyanates such as those disclosed in US Pat. Aromatic polyisocyanates such as toluene diisocyanate (TDI), methylene diphenyl diisocyanate (MDI), and polymethylene polyphenyl isocyanate (PMDI) are also known to be useful, but aliphatic isocyanates Is much more stable to hydrolysis and the prepolymer is dispersed in water. Thus, it is normally believed that the reaction between isocyanate and difunctional amine occurs in a more controlled and predictable manner.

  Films prepared from natural rubber latex are common and are considered to have desirable properties from the standpoint of comfort and utility. Unfortunately, natural rubber latex also contains proteins and other materials such as sulfur-containing curing agents that can be irritating to the skin and may cause severe allergic reactions in some people. Yes.

  (Patent Document 11) published on October 19, 2000 discloses a polyurethane film and a dispersion for adjusting the polyurethane film. The dispersion is prepared from a polyurethane prepolymer formulation comprising a diisocyanate and an active hydrogen-containing material. In the first step, the dispersion forms a prepolymer, and in a subsequent step, a water-soluble dispersion of the prepolymer is formed in the presence of an anionic surfactant, and both steps are substantially present in an organic solvent. It is formed by the method of two steps or more performed in the place where it does not.

  Elastic film with good moisture management can provide protection from the environment, such as bacteria and chemicals. In particular, the potential threat from chemical and biological agents is increasing, and the need for such materials is increasing. Recent events have shown the need for comfortable gloves that police officers and post workers can wear for extended periods of time. Latex gloves are usually less resistant to breakage and can pose additional health risks, including fatal allergic reactions of certain individuals. Nitrile gloves have good fracture resistance but have a high modulus and can therefore cause fatigue due to long-term use.

  Polyurethane elastomers can be selected as an alternative material, but it has been found that some polyurethane gloves weaken when exposed to water or rubbing alcohol. This will prevent long-term use of such gloves.

U.S. Pat. No. 3,178,310 US Pat. No. 3,919,173 U.S. Pat. No. 4,442,259 U.S. Pat. No. 4,444,976 US Pat. No. 4,742,095 U.S. Pat. No. 4,292,226 US Pat. No. 4,431,763 US Pat. No. 4,433,095 US Pat. No. 4,501,852 US Pat. No. 5,494,960 International Publication No. 00/61651 Pamphlet US Provisional Application No. 60 / 423,478 US patent application Ser. No. 10 / 701,317 US Pat. No. 4,127,513 US Pat. No. 4,139,567 US Pat. No. 4,153,186 U.S. Pat. No. 4,228,272 US Pat. No. 4,235,751 German Patent Application No. 86-3606479 German Patent Application No. 83-3346136 US patent application Ser. No. 10 / 700,859 Kirk-Othmer Encyclopedia of Chemical Technology, 4th edition, 1993, pp. 624-638, New York, John Wiley & Sons (John Wiley & Sons). B. K. Kim, Colloid. Polym. Sci. 1996, 274, 599-611. J. M. Hammond et al., J. Polym. Sci., Part A, 1971, Vol. 9, p. 295 Hongzhi Zhang et al., J. Appl. Polym. Sci., 1999, 73, 2303.

  It has been found that if polyurethane is carefully formulated, a glove having a number of desired properties can be obtained.

The present invention discloses a product comprising a water-soluble polyureaurethane dispersion. These articles have a tensile strength greater than 2030 psi, a fracture strength greater than 200 pounds / inch, and a tear strength per thickness greater than 20 N / mm. They also show improved solvent resistance. A method of manufacturing these articles is also disclosed, the method comprising: a) immersing the mold in a coagulant solution and drying at a high temperature;
b) immersing the mold coated with the coagulant solution in the water-soluble polyureaurethane dispersion and drying;
c) subjecting the coated mold to a salt leaching bath;
d) drying the coated mold at an elevated temperature before removing the article from the mold.

  The present invention discloses the use of stable water-soluble polyureaurethane dispersions using THF homopolymers and / or copolymers as glycols and aromatic diisocyanates, but chain extenders, curing agents, or crosslinkers. Does not require the use of. This dispersion method produces stable colloidal particles of elastomeric polyurethane having a wide range of utility. This method is robust and is not relatively complicated in that it does not require a series of separation steps as described in previous work (see, for example, US Pat. In general, aliphatic isocyanates are preferred for the production of water-soluble polyurethane colloids (see generally (Non-Patent Document 2)). These aliphatic isocyanates and various glycols are reacted to form an oligomer prepolymer and then dispersed in water containing an equivalent amount of diamine. The amount of diamine is determined by n-butylamine titration and back calculation, and NCO percent and equivalents are added. Aliphatic isocyanates are relatively stable in water, so diamines react with isocyanates, and the prepolymer is chain extended through urea linkages. Applicant of the present application filed Nov. 4, 2003, which is a US Patent Publication (Patent Document 12) filed Nov. 4, 2002, which describes other water-soluble polyureaurethane dispersions, which are incorporated herein in their entirety. See also owned co-pending US Patent Publication (Patent Document 13).

  However, with careful selection of reagents and conditions, the isocyanate undergoing hydrolysis can be controlled to the desired amount and subsequently reacted with additional isocyanate to produce the ethylenediamine described in (Non-Patent Document 2). And high molecular weight (e.g., molecular weight suitable for forming an independent film, typically more than 100,000, preferably more than 200,000) without the addition of common aliphatic diamines such as found. This is important. This is because the reaction between diisocyanate and diamine in water is rate limiting, and it cannot be guaranteed that all added amine will be consumed during the reaction. Any unreacted amine remaining in materials made by other methods can cause skin irritation or sensitization in certain applications.

  It has been found that the use of aromatic diisocyanates under appropriate reaction temperatures and dispersion conditions may be suitable for making the dispersions of the present invention. Examples of aromatic diisocyanates are MDI, TDI, PMDI and the like. The amount of NCO% in the prepolymer determines the physical properties of the final film produced from the dispersion. A preferred range of NCO% is 2-4%.

  Another critical factor that enables the stability and simplicity of this method is the careful manipulation of polar soft segments. One soft segment that provides a good dispersion in combination with aqueous dispersion and appropriate hard segment conditions is a low molecular weight PTMEG with a diol containing selected acid functional groups. Another applicable is a THF copolymer soft segment containing an appropriate amount (usually 25-60 weight percent) of ethylene glycol as a comonomer. Methods for preparing such copolymers include US Patent Publication (Patent Document 14), US Patent Publication (Patent Document 15), US Patent Publication (Patent Document 16), US Patent Publication (Patent Document 17), US Patent Publication ( (Patent Literature 18); (Patent Literature 19) and (Patent Literature 20); (Non-Patent Literature 3) and (Non-Patent Literature 4). An example of a diol containing an acid functional group is 2,2'dimethanolpropionic acid (DMPA). The ethylene oxide comonomer content in PTMEG is 25-60% by weight.

  Such a dispersion can be prepared by using a hydrophilic soft segment. The hydrophilic soft segment is made by reacting a polyurethane prepolymer with an ethylene glycol copolymer of THF with an ethylene glycol content higher than 20% or a polyurethane prepolymer with PTMEG containing a small amount of sterically crowded acid-containing diol. Means that A preferred range for the EO content in the copolymer is 25% to 60% by weight. A preferred crowded acid diol is DMPA. A preferred DMPA range is 3-5% by weight. The preferred molecular weight of poly (EO-co-THF) is 1000-3500, and the most preferred molecular weight is 2000. The preferred molecular weight of PTMEG is 700-1500, and the most preferred molecular weight is 1000.

Generally, the dispersion of the present invention is made by mixing isocyanate and glycol in nitrogen at a temperature of about 90 ° C. (80 ° C. to 100 ° C.) for several hours to form a prepolymer. The shear rate and force applied to the dispersion mixture are important and are described in FIG. When an excessive shear force is applied, the dispersion becomes unstable and may break apart. In general, the preferred range of shear force is 500-1700 Newtons. The mixing time is usually 2 to 5 minutes. A crowded acid diol (eg, DMPA and others listed in Table 1 of (Non-Patent Document 2)) can be added in this step as well. Other methods of adding ionic content include the addition of crowded acid diol salts (eg, sodium dimethylolpropionate), the addition of sulfonates (eg, 2-sodium 1,4 butanediol), or one alkyl group And by the addition of a cation center such as the addition of a tertiary amine having two alkylol groups. At the end of the mixing time, the amount of excess isocyanate in the prepolymer can be determined by n-butylamine titration and back calculation. After the reaction product has cooled to room temperature, a solvent (generally a water-miscible organic solvent such as acetone or methyl ethyl ketone (MEK)) is optionally used to dilute the prepolymer to about 75 weight percent solution. . This solution is poured into a cooled (ie 0-10 ° C.) aqueous solution containing a surfactant that may be anionic, cationic or nonionic. A preferred surfactant is sodium dodecylbenzene sulfonate, or Triton X100 (Dow Chemical Co., Midland, MI, USA). The preferred amount of surfactant is 0.1-2% by weight, the most preferred amount is 0.5-1% by weight. When an acid-containing diol is used, an inorganic relatively weak base (for example, NaHCO ₃ , Na (CO ₃ ) ₂ , NaAc (where Ac represents acetate), NaH ₂ PO _4, etc.) is added and dispersed. Can also be improved. These inorganic bases tend to be relatively odorless and not irritating to the skin. Alternatively, triethylamine can be used as the base. In this case, it is recommended to use less than one equivalent of amine to acid to minimize the potential odor. Dispersed water generally contains less than 1 equivalent of amine to neutralize the acid in DMPA, and the pH of this 1 molar aqueous solution does not exceed 10. The dispersion temperature is important for the formation of small particles. A preferable dispersion temperature is 0 to 10 ° C. The solids content of the dispersion is 10-60%, typically 10-30%. The solids content of the resulting dispersion is generally about 10-30 weight percent, as determined by drying the sample in an oven at 100 ° C. for 2 hours and comparing the weight before and after drying.

  The present invention is a co-pending US patent application (patent document 21) owned by the present applicant and filed on November 4, 2003, filed November 4, 2003, which is incorporated herein by reference in its entirety. The present invention relates to these articles prepared from the water-soluble dispersion described in the publication (Patent Document 13).

  When used as films and gloves, these materials exhibit improved resistance to solvents, including isopropyl alcohol and DMAc. Also, the off-gas of the film material is reduced and these films and gloves are generally acceptable for use in a clean room. As shown in the examples below, these films and gloves not only show improved chemical and solvent resistance, but also show improved fracture and tear resistance. These usually have a modulus of 100% elongation (i.e., about 200-500 psi), allowing the film or glove to be easily stretched. This also shows a low residual set and returns to its original shape after stretching. The preferred thickness of the glove is 3-6 mils, but other thicknesses may be used.

  The data below shows that the material of the present invention has a softer stretch or flat stress-strain curve than other test articles close to natural rubber.

(Definition)
Unless otherwise specified, all chemicals and reagents were obtained from Aldrich Chemical Company, Milwaukee, Wis ..

  Typically, the applicant's co-pending US Patent Publication (Patent Document 21) filed on November 4, 2003 and the United States Patent Publication filed on November 4, 2003, which are hereby incorporated by reference in their entirety. A dispersion was prepared as described in (Patent Document 13).

(material)
US Patent Publication (Patent Document 14), US Patent Publication (Patent Document 15), US Patent Publication (Patent Document 16), US Patent Publication (Patent Document 17), US Patent Publication (Patent Document 18); And (patent document 20); (non-patent document 3) and (non-patent document 4), poly (ethylene glycol-co-THF) was obtained. PTMEG-1000 and PTMEG-1800 are DuPont Terrathane (registered trademark) products. All glycols were dried under vacuum at 90 ° C. for 12 hours before use. MDI was purified by heating to 50 ° C. DMPA, MEK, TEA, and SDBS were purchased and used without further purification. The mixing equipment used to make the dispersions were IKA® Works, Inc.'s IKA® mixer, model T25 BASIC SI, and Charles Ross and Son Company. Ross mixer / emulsifier model HSM-100LC. The IKA® mixer was operated at 11,000 rpm, and the Ross mixer was operated at 7,000-8,000 rpm.

(General procedure for preparing water-soluble polyurethane dispersion)
Prepolymers were prepared by mixing MDI, glycol (and DMPA if necessary) in nitrogen at 90 ° C. for 3-5 hours. The amount of excess NCO remaining after the coupling reaction was determined by titration. When using a solvent to dilute the prepolymer, after cooling the reaction product to room temperature, the solvent was added to make a typically 75 wt% solution. The prepolymer was placed in a tube and slowly added by air pump to a cooled aqueous solution containing a surfactant and optionally a base. The solid content of the dispersion is about 10-30%.

(Gloves forming method)
To form the glove, the mold is immersed in the coagulant solution. The coagulant solution is typically 10-20% Ca (NO ₃ ) ₂ and 0-10% CaCO ₃ . The mold is then dried at 100 ° C. for 5 minutes. Next, this mold is immersed in a water-soluble polyurethane dispersion at 10 to 50 ° C., and then cooled at 10 to 40 ° C. The coated mold is then leached by immersing it in water at 20-70 ° C. and then dried at 90-150 ° C. for 30 minutes. The gloves are then removed from the mold.

Example 1
In a three-neck round bottom flask in a dry box, 156.4 g (0.624 mol) of MDI, 391 g (0.391 mol) of PTMEG-1000 glycol and 19.9 g (0.149 mol) of DMPA (3. 5 wt%). The flask was then moved into the hood and equipped with an overhead stirrer. The mixture was stirred at 90 ° C. for 4 hours under nitrogen. Titration of the mixture reveals an NCO content of 5.32%.

  200 ml of MEK is added to this mixture to make a MEK solution with a solid content of 74%. Next, this glycol / MEK solution was gradually added to 4 liters of a 2% SDBS solution containing 15 g of TEA at 0 ° C. via a caulking tube. The ratio of TEA to DMPA was 1: 1. Dispersion was performed using a Ross mixer and a small amount of precipitate was observed. After filtering the precipitate, a dispersion with a final solids content of 11.5% was obtained. The particle size of the precipitate was 1063 nm as measured with a Coulter N4MD Analyzer. The molecular weight of the obtained material was 237,000 as measured by GPC (polystyrene standard).

(Comparative Example A)
A mixture was made as described in Example 1 above, except that no SDBS surfactant was added and 1.7 g NaHCO ₃ was used as the base. The ratio of NaHCO ₃ to DMPA is 1: 1. A dispersion was not obtained.

A similar mixture was made once again, but this time with 2 wt% SDBS surfactant containing NaHCO ₃ added. Precipitation was observed. After the precipitate was filtered off, a dispersion having a solid content of 8.2 wt% was obtained. The film was cast but had only a slight strength.

(Comparative Example B)
In a dry box, in a three-necked round bottom flask, 78 g (0.624 mol) of MDI was mixed with 360 g of PTMEG-1800 glycol and 16 g of DMPA (representing 3.5 wt% of the total amount). The flask was then moved into the hood and equipped with an overhead stirrer. Under nitrogen, the mixture was stirred at 90 ° C. for 4 hours. Titration of the mixture reveals an NCO content of 5.32%.

  To this mixture, 400 ml of MEK was added. Then, 204 g of glycol / MEK solution was gradually added to 1.1 liter of 2% SDBS solution containing 2.85 g of TEA at 0 ° C. via a caulking tube. The ratio of TEA to DMPA is 1: 1. No dispersion was obtained from this mixture.

Using the same procedure except that NaHCO ₃ was used as the base, a sponge type polymer was formed.

(Comparative Example C)
Experiments were performed as described in Comparative Example B above, except that a 30% EO / THF material (Sanyo) was used. When 2% surfactant / TEA was used, no dispersion was made and a large amount of precipitate was observed.

Moreover, when the experiment described in the above paragraph was performed using 0.5% surfactant / NaHCO ₃ , no dispersion was observed. A large amount of precipitate was observed.

(Comparative Example D)
The procedure was performed as described in Example 1 above, except that a 1.25% surfactant / NaHCO ₃ solution was used. Precipitation was observed. After the precipitate was filtered off, a dispersion having a solid content of 10.1% was obtained. The film was cast after evaporating the water. The film showed insufficient elasticity.

(Test results of articles made from water-soluble dispersion)
According to ASTM method F1342, the breaking strength of the gloves prepared from the dispersion by the method described above was measured. The elongation and thickness of this material was measured. The puncture load was calculated in pounds / thickness (inches). The results are found in Table 1 below.

  ASTM method D-624-98 was used to test the tear strength of gloves made according to the present invention. This test requires the film to be cut with a die, and then the sample placed in an Instron (Instron) device and torn. Record the load vs. elongation. Cut molds B and C were used. In order to guarantee the initial tear position, the test specimen for die B was cut with a razor. The punching die C had a steep angle of 90 degrees as a position for tearing, and was not cut. The test results are found in Table 2 below and indicate the tear strength (N / mm) per unit thickness.

なお、本発明は、以下の事項を特徴とする発明である。
１．水溶性ポリウレアウレタン分散液から作製されることを特徴とする物品。
２．前記物品が手袋、指サック、およびコンドームよりなる群から選択されることを特徴とする１に記載の物品。
３．２０３０ｐｓｉより高い引張強度を有することを特徴とする１に記載の物品。
４．少なくとも２００ポンド／インチの破壊強度を有することを特徴とする１に記載の物品。
５．材料の厚さあたりの引裂強度が少なくとも２０ニュートン／ｍｍであることを特徴とする１に記載の物品。
６．溶媒の攻撃に対する抵抗性が改善されたことを特徴とする１に記載の物品。
７．ａ）金型を凝固剤溶液に浸漬し、高温で乾燥させる工程と、
ｂ）凝固剤溶液をコーティングした金型を水溶性ポリウレアウレタン分散液に浸漬し、乾燥させる工程と、
ｃ）前記コーティングした金型を塩浸出浴にかける工程と、
ｄ）前記金型から物品を取り出す前に、前記コーティングした金型を高温で乾燥させる工程と
を含むことを特徴とする１に記載の物品の製造方法。

In addition, this invention is invention characterized by the following matters.
1. An article produced from a water-soluble polyureaurethane dispersion.
2. The article according to 1, wherein the article is selected from the group consisting of a glove, a finger sack, and a condom.
3. The article of 1, wherein the article has a tensile strength greater than 2030 psi.
4). The article of claim 1 having a breaking strength of at least 200 pounds per inch.
5. 2. Article according to 1, characterized in that the tear strength per thickness of the material is at least 20 Newtons / mm.
6). 2. The article according to 1, which has improved resistance to solvent attack.
7). a) immersing the mold in the coagulant solution and drying at high temperature;
b) a step of immersing a mold coated with a coagulant solution in a water-soluble polyureaurethane dispersion and drying;
c) subjecting the coated mold to a salt leaching bath;
and d) drying the coated mold at a high temperature before removing the article from the mold.

Claims (2)

An article made from a water-soluble polyureaurethane dispersion,
The dispersion contains a water-miscible organic solvent, polyureaurethane, and 0.1 to 2% by weight of SDBS surfactant, and does not contain an aliphatic chain extender.
The polyureaurethane includes an aromatic diisocyanate and a hydrophilic soft segment containing PTMEG having a molecular weight of 700 to 1500 and 3 to 5% by weight of 2,2 ′ dimethanolpropionic acid (DMPA), and the dispersion is solid. Article characterized in that the content is 10-30%. a) immersing the mold in the coagulant solution and drying at high temperature;
b) a step of immersing a mold coated with a coagulant solution in a water-soluble polyureaurethane dispersion and drying;
c) subjecting the coated mold to a salt leaching bath;
d) drying the coated mold at a high temperature before removing the article from the mold, and a method for producing an article made from a water-soluble polyureaurethane dispersion,
The water-soluble polyureaurethane dispersion contains a water-miscible organic solvent, polyureaurethane, and 0.1 to 2% by weight of SDBS surfactant, and does not contain an aliphatic chain extender.
The polyureaurethane includes an aromatic diisocyanate and a hydrophilic soft segment containing PTMEG having a molecular weight of 700 to 1500 and 3 to 5% by weight of 2,2 ′ dimethanolpropionic acid (DMPA), and the dispersion is solid. A method characterized in that the minute is 10-30%.