U.S. patent application number 11/165137 was filed with the patent office on 2006-06-29 for aqueous aromatic polyurethane elastomeric articles and method of fabricating the same.
This patent application is currently assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE. Invention is credited to Kai Wen Chang, Yih-Her Chang, Chih-Chien Chen, Ruei-Shin Chen, Jer-Young Chern.
Application Number | 20060142475 11/165137 |
Document ID | / |
Family ID | 36612641 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060142475 |
Kind Code |
A1 |
Chen; Ruei-Shin ; et
al. |
June 29, 2006 |
Aqueous aromatic polyurethane elastomeric articles and method of
fabricating the same
Abstract
An aqueous aromatic polyurethane elastomeric article is
fabricated by an aqueous aromatic polyurethane dispersion, prepared
by polyurethane prepolymers comprising wholly aromatic
diisocyanates, especially toluene diisocyanate (TDI). And, a method
of fabricating the elastomeric article is provided.
Inventors: |
Chen; Ruei-Shin; (Changhua
County, TW) ; Chen; Chih-Chien; (Hsinchu City,
TW) ; Chern; Jer-Young; (Hsinchu City, TW) ;
Chang; Yih-Her; (Hsinchu-City, TW) ; Chang; Kai
Wen; (Taichung City, TW) |
Correspondence
Address: |
BIRCH STEWART KOLASCH & BIRCH
PO BOX 747
FALLS CHURCH
VA
22040-0747
US
|
Assignee: |
INDUSTRIAL TECHNOLOGY RESEARCH
INSTITUTE
|
Family ID: |
36612641 |
Appl. No.: |
11/165137 |
Filed: |
June 24, 2005 |
Current U.S.
Class: |
524/591 ;
264/215 |
Current CPC
Class: |
C08G 18/4854 20130101;
C08G 18/12 20130101; C08G 18/0823 20130101; C08G 18/3228 20130101;
B29K 2075/00 20130101; B29C 41/14 20130101; C08G 18/7621 20130101;
B29C 41/003 20130101; C08G 18/12 20130101; C08G 18/4808
20130101 |
Class at
Publication: |
524/591 ;
264/215 |
International
Class: |
C08G 18/08 20060101
C08G018/08; B29D 7/00 20060101 B29D007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 2004 |
TW |
93140986 |
Claims
1. An aqueous aromatic polyurethane elastomeric article fabricated
by an aqueous aromatic polyurethane dispersion, prepared by
polyurethane prepolymers comprising wholly aromatic
diisocyanates.
2. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the aromatic diisocyanate is toluene
diisocyanate (TDI).
3. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the aqueous aromatic polyurethane dispersion is
prepared by an aromatic diisocyanate, at least one polyol, a
low-molecular weight compound with at least two functional groups
capable of reacting with isocyanate groups, and a hydrophilic
compound containing active hydrogen.
4. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the elastomeric article has a thickness of
0.05.about.0.35 mm.
5. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the elastomeric article has an elongation of
150.about.1000%.
6. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the elastomeric article has an elongation
exceeding 650%.
7. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the elastomeric article has a tensile strength
of 30.about.850 kg/cm.sup.2.
8. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the elastomeric article has a tensile strength
exceeding 170 kg/cm.sup.2.
9. The aqueous aromatic polyurethane elastomeric article as claimed
in claim 1, wherein the elastomeric article has a 500% modulus of
10.about.150 kg/cm.sup.2.
10. The aqueous aromatic polyurethane elastomeric article as
claimed in claim 1, wherein the elastomeric article has a 500%
modulus less than 70 kg/cm.sup.2.
11. The aqueous aromatic polyurethane elastomeric article as
claimed in claim 1, wherein the elastomeric article comprises a
glove, condom, or catheter.
12. A method of fabricating an aqueous aromatic polyurethane
elastomeric article as claimed in claim 1, comprising: providing an
aqueous aromatic polyurethane solution; dipping a mold in the
solution; forming an aqueous aromatic polyurethane film on the mold
surface after the mold is lift out of the solution; drying and
cooling the film; and stripping the film and forming an aqueous
aromatic polyurethane elastomeric article.
13. The method as claimed in claim 12, wherein the aqueous aromatic
polyurethane solution is prepared by the following steps,
comprising: mixing aromatic diisocyanate, polyol, hydrophilic
groups-containing diol, and solvent to form a solution comprising
aromatic polyurethane prepolymers; dispersing the prepolymers in an
aqueous phase of the solution and extending the chain thereof; and
forming the aqueous aromatic polyurethane solution after the
solvent content is reduced by distillation.
14. The method as claimed in claim 12, wherein the aqueous aromatic
polyurethane solution comprises surfactant, thickener, humectant,
stabilizing reagent, deforming agent, cross-linking agent, leveling
agent, or plasticizer.
15. The method as claimed in claim 12, wherein the mold is ceramic,
metal, plastic, or rubber.
Description
BACKGROUND
[0001] The present invention relates to an elastomeric article, and
more specifically to an aqueous aromatic polyurethane elastomeric
article and a method of fabricating the same.
[0002] Natural rubber latex gloves are popular for use as safety
gloves. Such natural rubber latex gloves, however, may cause
allergies or contact dermatitis due to their composition, such as
proteins allergens, and chemical substances added during the glove
fabrication. To avoid these dangers, some methods have been
provided, for example, reduction of natural latex quantities or
replacement with hypo-allergenic polymers. Nevertheless,
elastomeric articles are often uncomfortable and not easy to wear.
Powdered or halogenated gloves are proved to increase lubricity of
the surface of gloves and more convenience to wear. Nevertheless,
the powder on surgical gloves may contaminate sterile areas and
cause further complications for the patient. For use in a precise
equipment in the electrical/electronic industry, powder may be a
serious contaminant. Additionally, halogenated gloves may
deteriorate quickly, resulting in embrittlement or color
fading.
[0003] Current aqueous polyurethane (PU) gloves can provide more
comfortable donnability and avoid powder problems. Those aqueous
polyurethanes are made from aliphatic or cycloaliphatic
diisocyantes, such as isophorone diisocyanate (IPDI), hexamethylene
diisocyanate (HDI), and 4,4'-dicyclohexylmethane diisocyanate
(HMDI), will give better hydrolytic resistance. Such diisocyantes,
however, are expensive, increasing production cost. Additionally,
conventional aqueous polyurethane may crack during drying due to
poor fusion between PU particles after dipping or coating,
resulting in deterioration of original characteristics. Thus, an
aqueous polyurethane elastomeric article with low cost and optimal
mechanical characteristics is required to be suitable for
preparation in dipping or coating.
SUMMARY
[0004] The invention provides aqueous aromatic polyurethane
elastomeric articles fabricated by an aqueous aromatic polyurethane
dispersion, prepared by polyurethane prepolymers comprising wholly
aromatic diisocyanates, especially toluene diisocyanate (TDI).
[0005] The invention also provides a method of fabricating aqueous
aromatic polyurethane elastomeric articles, comprising the
following steps. An aqueous aromatic polyurethane solution is
provided. A mold is then dipped in the solution. After the mold is
lift out of the solution, an aqueous aromatic polyurethane film is
formed on the mold surface. The film is then dried and cooled.
After the film is stripped, an aqueous aromatic polyurethane
elastomeric article is formed.
[0006] A detailed description is given in the following
embodiments.
DETAILED DESCRIPTION
[0007] The invention provides aqueous aromatic polyurethane
elastomeric articles fabricated by an aqueous aromatic polyurethane
dispersion, prepared by polyurethane prepolymers comprising wholly
aromatic diisocyanates, especially toluene diisocyanate (TDI).
[0008] The aromatic diisocyanate comprises at least one aromatic
ring, such as phenyl and diphenyl. Substituted groups of the
aromatic ring may comprise halogen atoms, nitro, cyano, alkyl,
alkoxy, alkyl halide, hydroxyl, carboxyl, amide, or amino.
[0009] The aromatic diisocyanate has formula (I) or (II):
##STR1##
[0010] wherein R.sub.1 may comprise hydrogen atom or C1-6 alkyl,
R.sub.2 and R.sub.3 may be the same or different, such as hydrogen
atom, C1-6 alkyl, C1-6 alkoxy, or C6 aryl, and n may be
0.about.3.
[0011] The aromatic diisocyanate may comprise toluene diisocyanate
(TDI), p-phenylene diisocyanate (PPDI), 4,4'-diphenylmethane
diisocyanate (MDI), or p,p'-bisphenyl diisocyanate (BPDI).
[0012] The aqueous aromatic polyurethane dispersion is prepared by
an aromatic diisocyanate, at least one polyol, a low-molecular
weight compound with at least two functional groups capable of
reacting with isocyanate groups, and a hydrophilic compound
containing active hydrogen. The low-molecular weight compound has a
molecular weight of 60.about.300.
[0013] In a method of fabricating an aqueous aromatic polyurethane
elastomeric article, aqueous aromatic polyurethane solution is
provided, and a mold is dipped in the solution. The mold may be
ceramic, metal, plastic, or rubber. After the mold is lift out of
the solution, an aqueous aromatic polyurethane film is formed on
the mold surface. The film is then dried and cooled. After the film
is stripped, an aqueous aromatic polyurethane elastomeric article
is formed.
[0014] According to practical requirements, the aqueous aromatic
polyurethane solution may comprise surfactant, thickener,
humectant, stabilizing reagent, deforming agent, cross-linking
agent, leveling agent, or plasticizer. The aqueous aromatic
polyurethane solution is prepared as follows. An aromatic
diisocyanate, polyols, a diol containing hydrophilic groups, and
solvents are mixed to form a solution comprising aromatic
polyurethane prepolymers. The solvent is an organic solvent having
a boiling point of 50.about.2000.degree.C. Next, the prepolymers
are dispersed in an aqueous phase of the solution and extended by a
chain-extending compound such as diamine or diol. After the solvent
content is reduced by low-vacuum distillation or steam distillation
if necessary, the aqueous aromatic polyurethane solution with
organic solvent less than 15% and solid contents of 10.about.65 wt
% is prepared.
[0015] The low-cost and high-performance elastomeric article of the
invention is prepared by aqueous aromatic polyurethane, without
additional modifiers or additives. Mechanical properties of the
elastomeric article may be similar to rubber or superior thereto,
that is, original characteristics of aqueous aromatic polyurethane
are maintained during dipping or coating.
[0016] The elastomeric article has an elongation of
150.about.1000%, preferably exceeding 650%, a tensile strength of
30.about.850 kg/cm.sup.2, preferably exceeding 170 kg/cm.sup.2 ,a
500% modulus of 10.about.150 kg/cm.sup.2, preferably less than 70
kg/cm.sup.2, and a thickness of 0.05 .about.0.35 mm. The
elastomeric article may comprise glove, condom, or catheter.
[0017] According to product quality tests, an aqueous aromatic
polyurethane glove fabricated by the invention provides
convenience, ease, and softness. Even to wear for a long time,
there are no allergic reactions revealed. The gloves also provide a
room temperature surface resistivity of
10.sup.8.about.10.sup.10.OMEGA., effectively inhibiting static
electricity. Additionally, the powder-free gloves will be applied
in electronics and semiconductor industry. In general glove
fabrications, powdered gloves require twelve steps and 30.about.35
min, powder-free chlorinated gloves require 13.about.15 steps and
2.about.3 hours, while inner surface polymer-coating composite
gloves require 12.about.15 steps and 1.about.2 hours. The present
glove fabrication, however, merely requires 6 steps and 30 min,
demanding less consumption time, occupied space, manpower, and
production time. Further, long-term high-temperature cross-linking
vulcanization is not necessary in these processes, which are
benefit for saving power consumption and improving competitive
ability of products.
[0018] Without intending to limit it in any manner, the invention
will be further illustrated by the following examples.
EXAMPLE 1
Fabrication of PU-A Elastomeric Article
[0019] An aqueous aromatic polyurethane dispersion was prepared as
follows. 10.36 g dimethylol butyric acid (DMBA) and 17.39 g acetone
were added to a reaction tank with nitrogen gas, reflux and stirred
until a uniform phase was formed. 40.28 g mixture of 2,4-toluene
diisocyante and 2,6-toluene diisocyanate with a ratio of 80:20 were
then added and reacted at 60.degree. C. for 1.5 hours. Next, 119.49
g polytetramethylene glycol (PTMEG) and 29.87 g polypropylene
glycol (PPG) were added and reacted at 60.degree. C. for 4 hours.
After cooling to 50.degree. C., 7.07 g triethyl amine (TEA) was
added to neutralize for 20 min to form neutralized and hydrophilic
prepolymers. 190 g such prepolymers were then rapidly added to
374.3 g deionized water and stirred at 500 rpm to disperse the
prepolymers. Till the NCO value lowered to 2.66 wt %, 1.75 g
ethylene diamine (EDA) was added to extend the polymer chain at
room temperature for 2 hours. After acetone was removed by
low-vacuum distillation, an aqueous aromatic polyurethane
dispersion with 30% solid contents was prepared.
[0020] An aqueous aromatic polyurethane elastomeric article was
then fabricated as follows. A ceramics mold was first dipped in an
aqueous solution containing a coagulating agent, and dried at
60.degree. C. to give a pretreated surface. Then the mold was
dipped in the aqueous aromatic polyurethane dispersion at
30.degree. C. for 30 sec. Next, the mold was slowly lift and
rotated. An aqueous aromatic polyurethane film with a uniform
thickness was form on the mold surface. After the further procedure
of drying at 90.degree. C. for 10 min, cooling and stripping, an
aqueous aromatic polyurethane elastomeric article (PU-A) was
formed. The PU-A had an elongation of 700%, a tensile strength of
360 kg/cm.sup.2, and a 500% modulus of 86 kg/cm.sup.2.
EXAMPLE 2
Fabrication of PU-B Elastomeric Article
[0021] An aqueous aromatic polyurethane dispersion was prepared as
follows. 10.36 g dimethylol butyric acid (DMBA) and 17.39 g
N-methyl pyrrolidone (NMP) were added to a reaction tank with
nitrogen gas, reflux and stirred until a uniform phase was formed.
38.05 g mixture of 2,4-toluene diisocyante and 2,6-toluene
diisocyanate with a ratio of 80:20 were then added and reacted at
60.degree. C. for 1.5 hours. Next, 121.27 g polytetramethylene
glycol (PTMEG) and 30.32 g polypropylene glycol (PPG) were added
and reacted at 60.degree. C. for 4 hours. After cooling to
50.degree. C., 7.07 g triethyl amine (TEA) was added to neutralize
for 20 min to form neutralized and hydrophilic prepolymers. 190 g
such prepolymers were then rapidly added to 293.7 g deionized water
and stirred at 500 rpm to disperse the prepolymers. Till the NCO
value lowered to 1.86 wt %, 1.32 g ethylene diamine (EDA) was added
to extend the polymer chain at room temperature for 2 hours. An
aqueous aromatic polyurethane dispersion with 35% solid contents
was prepared.
[0022] An aqueous aromatic polyurethane elastomeric article was
then fabricated as follows. A ceramics mold was first dipped in an
aqueous solution containing a coagulating agent, and dried at
60.degree. C. to give a pretreated surface. Then the mold was
dipped in the aqueous aromatic polyurethane dispersion at
30.degree. C. for 30 sec. Next, the mold was slowly lift and
rotated. An aqueous aromatic polyurethane film with a uniform
thickness was form on the mold surface. After the further procedure
of drying at 90.degree. C. for 10 min, cooling and stripping, an
aqueous aromatic polyurethane elastomeric article (PU-B) was
formed. The PU-B had an elongation of 730%, a tensile strength of
300 kg/cm.sup.2, and a 500% modulus of 60 kg/cm.sup.2.
EXAMPLE 3
Fabrication of PU-C Elastomeric Article
[0023] An aqueous aromatic polyurethane dispersion was prepared as
follows. 93.24 g dimethylol butyric acid (DMBA) and 156.52 g
N-methyl pyrrolidone (NMP) were added to a reaction tank with
nitrogen gas reflux and stirred until a uniform phase was formed.
362.51 g mixture of 2,4-toluene diisocyante and 2,6-toluene
diisocyanate with a ratio of 80:20 were then added and reacted at
60.degree. C. for 1.5 hours. Next, 1034.04 g polytetramethylene
glycol (PTMEG) and 310.21 g polypropylene glycol (PPG) were added
and reacted at 60.degree. C. for 4 hours. After cooling to
50.degree. C., 63.63 g triethyl amine (TEA) was added to neutralize
for 20 min to form neutralized and hydrophilic prepolymers. 1900 g
such prepolymers were then rapidly added to 2937 g deionized water
and stirred at 500 rpm to disperse the prepolymers. Till the NCO
value lowered to 2.58 wt %, 16.7 g ethylene diamine (EDA) was added
to extend the polymer chain at room temperature for 2 hours. An
aqueous aromatic polyurethane dispersion with 35% solid contents
was prepared.
[0024] An aqueous aromatic polyurethane elastomeric article was
then fabricated as follows. A ceramics mold was first dipped in an
aqueous solution containing a coagulating agent, and dried at
60.degree. C. to give a pretreated surface. Then the mold was
dipped in the aqueous aromatic polyurethane dispersion at
30.degree. C. for 30 sec. Next, the mold was slowly lift and
rotated. An aqueous aromatic polyurethane film with a uniform
thickness was form on the mold surface. After the further procedure
of drying at 90.degree. C. for 10 min, cooling and stripping, an
aqueous aromatic polyurethane elastomeric article (PU-C) was
formed. The PU-C had an elongation of 690%, a tensile strength of
400 kg/cm.sup.2, and a 500% modulus of 28 kg/cm.sup.2.
[0025] Various mechanical characteristics such as elongation,
tensile strength, and 500% modulus of PU-A, PU-B, and PU-C
elastomeric articles provided by the invention, were compared with
that of a related natural rubber latex glove. The results are
illustrated in Table 1. TABLE-US-00001 TABLE 1 Tensile strength
500% modulus Sample Elongation (%) (kg/cm.sup.2) (kg/cm.sup.2) PU-A
700 360 86 PU-B 730 300 60 PU-C 690 400 28 Natural rubber 730 300
60 latex glove
[0026] The results indicate that the elastomeric articles of the
invention provide similar or better mechanical characteristics than
conventional materials, such as better elasticity and extensibility
(higher elongation and tensile strength) and better donnability,
softness, and flexibility (lower 500% modulus).
[0027] The elastomeric article fabrication provided by the
invention merely requires 6 steps and 30 min, demanding less
consumption time and process cost. Additionally, long-term
high-temperature cross-linking vulcanization is not necessary in
this fabrication, which is benefit for saving power consumption and
improving competitive ability of products.
[0028] While the invention has been described by way of examples
and in terms of preferred embodiment, it is to be understood that
the invention is not limited thereto. To the contrary, it is
intended to cover various modifications and similar arrangements
(as would be apparent to those skilled in the art). Therefore, the
scope of the appended claims should be accorded the broadest
interpretation so as to encompass all such modifications and
similar arrangements.
* * * * *