Patent Application
20180273675
This application claims priority from European application No. 15183605.3 filed on 3 Sep. 2015, the whole content of this application being incorporated herein by reference for all purposes.
The present invention relates to watch bands made from a fluorinated polyurethane polymer comprising recurring units derived from (per)fluoropolyether polymers.
Watch bands made from polymeric materials have been already disclosed in the art. For example, EP 2468127 B (BIWI S. A.) discloses jewelry items made from compositions comprising an elastomeric matrix having dispersed therein reinforcing fillers selected from the group consisting of microfibers, polytetrafluoroethylene nanoparticles, and mixtures thereof, said composite material being obtained from a composition comprising between 60% and 95% by weight of at least one elastomer, from 0% to 5% by weight of microfiber and from 0% to 40% by weight of polytetrafluoroethylene nanoparticles, based on the total weight of the composition, at least one of said reinforcing fillers being present. GB 2460890 A (EVENTUAL LIMITED) discloses a band comprising a protective portion housing an electronic tag and a second portion forming a band to be worn by a person, wherein the band material may be an elastomeric material such as rubber, in particular silicone rubber, and the protective portion may be made of metal or nylon.
Further to the above, wearable devices having at least one component made from or coated with a polyurethane polymer have been disclosed for example in US 2013/0197680 (NIKE INC.), US 2014/0155724 (KONINKLI JKE PHILIPS N. V.), US 2013/0088408 (ELECTRONICS AND TELECOMMUNICATIONS RESEARCH INSTITUTE) and JP H0925405 (NIPPON POLYURETHANE KOGYO KK).
Heat processable elastomeric polyurethanes comprising (per)fluoropolyether blocks were disclosed for example in U.S. Pat. No. 5,332,798 (AUSIMONT S.P.A.).
The Applicant faced the problem of providing new polymeric materials that can be useful for the manufacture of watch bands.
The Applicant has surprisingly found that a polyurethane polymer comprising recurring units derived from (per)fluoropolyether polymers has properties, notably stain, chemical and wear resistance, low temperature flexibility, silky feel and mechanical properties, such that it can be used for the manufacture of watch bands.
In addition, the Applicant has surprisingly found that the watch bands according to the present invention have improved properties, notably with respect to stain, abrasion and chemical resistance, when compared to watch bands obtained from fully hydrogenated polyurethanes.
Thus, in a first aspect, the present invention relates to a watch band made from a composition [composition (C)] comprising at least one fluorinated polyurethane [F-TPU polymer], said F-TPU polymer comprising recurring units derived from:
The Applicant has surprisingly found that the watch band made from said composition (C) provides a soft silky feeling to the touch, without the addition of plasticizer agents to said composition (C). This provides an advantage from the toxicological point of view, as the plasticizers can migrate of the surface of the object and from there to the skin of the user, thus resulting in possible problems of reddening of the skin, irritation and allergy.
For the purposes of the present description:
Preferably, the F-TPU polymer is a block copolymer, i.e. a polymer comprising blocks (also referred to as “segments”), each block comprising recurring units deriving from monomer (a), monomer (b), monomer (c) or monomer (d), as defined above.
Preferably, said F-TPU polymer has an average number molecular weight of from 30,000 to about 70,000 Da.
Preferably, said F-TPU polymer has a melting point (Tm) of from about 120° C. to about 240° C.
Preferably, said at least one monomer (a) has an average number molecular weight of from 500 to 4,000 Da, more preferably of from 1,000 to 4,000.
Preferably, said at least one monomer (a) is selected in the group comprising poly(ethylene)glycol, poly(propylene)glycol, poly(tetramethylen)glycol (PTMG), poly(1,4-butanediol)adipate, poly(ethandiol-1,4-butanedio) adipate, poly(1,6-hexandiol-neopentyl)glycol adipate, poly-caprolactone-diol (PCL) and polycarbonate-diol. Poly(tetramethylen)glycol, polycarbonate-diol and poly-caprolactone-diol being particularly preferred.
Preferably, said at least one monomer (b) is a hydroxy-terminated (per)fluoropolyether polymer [PFPE polymer] comprising a (per)fluoropolyoxyalkylene chain [chain (Rpf)] having two chain ends, wherein one or both chain ends terminates with at least one —OH group.
Preferably, at least one chain end of said chain (Rpf) terminates with a group of formula:
—CH2(OCH2CH2)t—OH (I)
wherein
t is 0 or from 1 to 5.
More preferably, both chain ends of said chain (Rpf) terminate with a group of formula (I) as defined above.
Preferably, said chain (Rpf) is a chain of formula
—(CFX)hO(Rf)(CFX′)i—
wherein
h and i, equal or different from each other, are equal to or higher than 1, preferably from 1 to 10, more preferably from 1 to 3;
X and X′, equal or different from each other, are —F or —CF3, provided that when h and/or i are higher than 1, X and X′ are —F;
(Rf) comprises, preferably consists of, repeating units Rº, said repeating units being independently selected from the group consisting of:
More preferably, chain (Rf) is selected from the following formulae (Rf-a) to (Rf-c):
—(CF2O)n(CF2CF2O)m(CF2CF2CF2O)p(CF2CF2CF2CF2O)q— (Rf-a)
wherein m, n, p, q are 0 or integers selected in such a way as chain Rf meets the above number average molecular weight requirement, with the proviso that if, p and q are simultaneously 0, n is not 0; when m is other than 0, the m/n ratio is preferably between 0.1 and 20; when (m+n) is other than 0, (p+q)/(m+n) is preferably between 0 and 0.2;
—(CF2CF(CF3)O)a(CF2CF2O)b(CF2O)c(CF(CF3)O)d— (Rf-b)
wherein a, b, c, d are 0 or integers selected in such a way as chain Rf meets the above number average molecular weight requirement; with the proviso that, at least one of a, c and d is not 0; when b is other than 0, a/b is preferably between 0.1 and 10; when (a+b) is different from 0 (c+d)/(a+b) preferably is between 0.01 and 0.5, more preferably between 0.01 and 0.2;
—(CF2CF(CF3)O)e(CF2O)f(CF(CF3)O)g— (Rf-c)
wherein e, f, g are 0 or integers selected in such a way as chain Rf meets the above number average molecular weight requirement; when e is other than 0, (f+g)/e is preferably between 0.01 and 0.5, more preferably between 0.01 and 0.2.
PFPE polymers wherein chain (Rf) complies with formula (Rf-a) as defined above, wherein p and q are 0, are particularly preferred in the present invention.
In a preferred embodiment, said PFPE polymer complies with the following formula (PFPE-I):
HO—(CH2CH2O)t—CH2—(Rpf)—CH2(OCH2CH2)u—OH (PFPE-I)
wherein
t and u are, each independently, 0 or from 1 to 5; and
Rpf is as defined above.
Preferably, said PFPE polymer has an average number molecular weight of from 400 to 10,000 Da, more preferably from 1,000 to 5,000.
In a preferred embodiment, the molar ratio between monomers (a) and monomers (b) is from 2 to 20, more preferably from 2 to 10.
In a preferred embodiment, the amount of monomers (b) is such that the F-TPU polymer comprises from 4 to 30 wt. % of fluorine.
Preferably, said at least one monomer (c) has a number molecular weight of 500 Da or lower, preferably from 10 to 500 Da.
Preferably, said at least one monomer (c) is selected in the group comprising, preferably consisting of, 4,4′-methylene-diphenylene-diisocyanate (MDI), 1,6-hexan-diisocyanate (HDI), 2,4-toluene-diisocyanate, 2,6-toluene-diisocyanate, xylilen-diisocyanate, naphthalene-diisocyanate, paraphenylen-diisocyanate, hexamaethylen-diisocyanate, isophorone-diisocyanate, 4,4′-dicyclohexyl-methane-diisocyanate and cyclohexyl-1,4-diisocyanate.
4,4′-methylene-diphenylene-di-isocyanate (MDI), 1,6-hexan-diisocyanate (HDI) and hexamaethylen-diisocyanate being particularly preferred.
Preferably, said at least one monomer (d) is selected in the group comprising, preferably consisting of, ethylene-glycol, 1,4-butanediol (BDO), 1,6-hexane diol (HDO), N,N-diethanolamine and N,N-diisopropanolaniline.
BDO and HDO being particularly preferred.
In a preferred embodiment, the sum of blocks deriving from monomers (c) and (d) is from 10 to 60 wt. % based on the total weight of the F-TPU polymer.
Those skilled in the art would readily understand that blocks comprising recurring units derived from monomers (a) and (b) are rubber-like blocks, while blocks comprising recurring units derived from monomers (c) and (d) are hard blocks.
In a preferred embodiment, at least 80% of the blocks comprising recurring units derived from said monomers (b) [blocks B] are linked, at least one of their ends, to a block comprising recurring units derived from monomers (a) [blocks A] through a block comprising recurring units derived from monomers (c) [blocks C].
In other words, at least 80% of blocks B are contained in a sequence of the following type: -[A-C—B-C]-.
Advantageously, the F-TPU polymer can be prepared following the procedures disclosed in U.S. Pat. No. 5,332,798 (AUSIMONT S.P.A.), in particular in Example 15.
According to a preferred embodiment, the watch band is made from a composition (C) that is free of plasticizer agents.
Preferably, said composition (C) comprises the F-TPU polymer as defined above as the main component.
More preferably, said F-TPU polymer is in an amount of at least 60 wt. %, more preferably at least 80 wt. %, even more preferably at least 85 wt. % based on the total weight of said composition (C).
In addition to the F-TPU polymer, said composition (C) can optionally comprise further additives, such as for example antioxidants, thermal stabilizers, dyestuffs and fillers.
Embodiments wherein said composition (C) is essentially made of said F-TPU polymer in combination with an amount of up to 1 wt. % of any of the additives listed above are also encompassed by the present invention.
The watch band according to the present invention is sufficiently stretchable and resilient such that even when stretched, for example over the wrist or other parts of the body of a user, it returns towards its original shape and is held in place on the wrist by tension, without requiring a clasp, buckle or other dedicated attachment device.
Most commonly, the watch band according to the present invention is made such that it can be worn around the wrist of a user, but it can be suitable also for wearing around other parts of the body of the user, such as the neck, finger or head.
The watch band according to the present invention can be made following methods known in the art.
As an example, the watch band can be manufactured by a process comprising the following steps:
Preferably, said mould is in the shape of a band. Any suitable size, shape and form of the mould can be used, dependent on the desired size, shape and form of the band to be produced.
Preferably, step (iv) comprises two steps, wherein the first step comprises heating at a first temperature for a time from 10 seconds to 10 minutes and the second step comprises heating at a second temperature, said second temperature being lower than said first temperature, for a time of from 30 seconds to 24 hours.
More preferably, said first temperature is from 120° C. to 300° C.
More preferably, said second temperature is from 50° C. to 200° C.
Alternatively, step (iv) comprises only one step of heating at a temperature of from 50° C. to 300° C. for a time of from 10 seconds to 24 hours.
Preferably, after step (iv) and before step (v), the mould is allowed to cool down.
Should the disclosure of any patents, patent applications and publications which are incorporated herein by reference conflict with the description of the present application to the extent that it may render a term unclear, the present description shall take precedence.
The invention will be herein after illustrated in greater detail by means of the Examples contained in the following Experimental Section; the Examples are merely illustrative and are by no means to be interpreted as limiting the scope of the invention.
Materials
H(OCH2CH2)pOCH2CF2O(CF2CF2O)m(CF2O)nCF2CH2O(CH2CH2O)pH
Preparation of F-TPU Polymer Specimens—Method A
F-TPU polymer specimens in the form of sheet were prepared starting from the abovementioned monomers following the same procedure detailed in Example 15 of U.S. Pat. No. 5,332,798 (to Ausimont S.p.A.) cited above.
F-TPU polymers thus obtained contained 20 wt. % of recurring units derived from monomers (b).
Preparation of F-TPU Polymer Specimens—Method B
F-TPU polymer specimens 5 to 7 and 8 (the latter as comparison) in the form of sheet were prepared as follows:
The compositions of the F-TPU polymers obtained following methods A and B described above and the compositions of comparative hydrogenated polyurethane polymers (H-TPU) are reported in the following Table 1.
As further comparison, a commercially available hydrogenated TPU (H-TPU 9*) was used. The monomers ratio for H-TPU 9* is not publicly available.
The mechanical properties of sheets made from F-TPU and H-TPU polymers were evaluated and the results are reported in Table 2.
The above results show that the F-TPU polymers according to the present invention have mechanical properties comparable with the mechanical properties of H-TPU polymers typically used in the production of the upper of footwear articles, and hence F-TPU polymers provide good mechanical properties to the finished upper.
The sheets were used in the Examples described hereinafter.
This test is considered to be predictive for both stain and chemical resistance.
The static contact angle (SCA) of a sessile drop (about 5 μL) of water and n-hexadecane as solvents was measured with the DSA30 instrument (Krüss GmbH, Germany). The SCA values as well as standard deviations were calculated among ten contact angles.
Surface free energy was calculated following the Owens, Wendt, Rabel and Kaelble method (WORK method), which is a standard method for calculating the surface free energy of a solid from the contact angle with several liquids.
The results are summarized in the following Table 3.
The above results show that the contact angle measured with both water (H2O) and hexadecane (C16) increased while the surface energy dropped down to the range from 15 to 16 mN/m compared to 31 mN/m for the hydrogenated thermoplastic polyurethane used as reference compound. These data are consistent with an increase in terms of stain resistance and chemical resistance conferred by the F-TPUs compared to H-TPU.
This test is considered to be predictive for both staining and abrasion resistance.
The test was performed with the instrument Taber Industries 5750 Linear Abraser, that was set to run at the following conditions:
Tests were performed once with dry denim and once with wet denim on F-TPU 1, F-TPU 2, F-TPU 3, F-TPU 5 and F-TPU 7.
Before performing the test with wet denim, denim was submerged in water for 10 second, then it was removed and water was squeezed out by hand so that denim did not drip but was wet to the touch.
The tests were performed as follows: a denim sample measuring approximately 30 mm×30 mm was fixed to a fixture in order to prevent shifting of the sample during the test. A sample of each F-TPU and of H-TPU was then placed on the denim sample and fixed to the fixture as well.
Checkpoints were set as follows:
Results for the dry test: no stain was observed for F-TPU 1, F-TPU 2, F-TPU 3, F-TPU 5 and F-TPU 7.
Results for the wet test: a very light halo was observed for F-TPU 1, F-TPU 2, F-TPU 3, F-TPU 5 and F-TPU 7.
A drop of each staining agent listed above was put into contact with the surface of a specimen made from F-TPU 1 and let for 24 hours at ambient conditions. The specimen was then cleaned with water.
A specimen made from H-TPU was used as comparison and treated as disclosed above.
The results are summarized in the following Table 4, wherein:
The above results clearly showed the increase in term of both stain and chemical resistance of the F-TPU specimen compared to the H-TPU specimen.
The haptic properties (notably the feeling of softness) of F-TPUs and H-TPUs were measured by testing the sheets of the materials subjectively by hand feel of 5 individuals.
Soft feel was measured subjectively by hand touch and rated on a scale from 1 to 5, with 1 being poor soft feel (hard feel) and 5 being excellent soft feel. Participants took part in this study individually, so they did not influence each other in their responses. Participants were presented with the four samples in a random order and asked to feel and rate them.
The results are summarized in the following Table 5.
The above results clearly showed that the sheets obtained with the F-TPUs according to the present invention showed better haptic properties, notably improved feeling of softness, when compared to sheets obtained from H-TPU polymer.
| Number | Date | Country | Kind |
|---|---|---|---|
| 15183605.3 | Sep 2015 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/066070 | 7/7/2016 | WO | 00 |
