Patent Application
20200112330
This application claims priority from European application No. 16178298.2 filed on 7 Jul. 2016, the whole content of this application being incorporated herein by reference for all purposes.
The present invention relates to a case for a portable electronic device, made from a composition comprising a fluorinated thermoplastic polyurethane polymer.
Following the introduction of portable electronic devices, such as smartphones, media players, laptop computers and the like, cases designed to receive and hold them were introduced in order to protect them for example from drops, abrasions and stains.
Cases for portable electronic devices have been disclosed in several patents and patent applications, such as for example WO 2011/053740 (BENLKIN INTERNATION, INC.), WO 2013/043462 (SPECULATIVE PRODUCT DESIGN, LLC.), WO 2014/145262 (MAV IP LLC.) and US 2015/0097009 (THULE ORGANIZATION SOLUTIONS, INC.).
Cases for portable electronic devices are typically made from hydrogenated thermoplastic polyurethane polymers (H-TPU) because they are more durable, elastic, and stronger than silicon or hydrocarbon cases. A waterproof cover for a mobile phone, wherein the cover body is made of polyurethane is disclosed for example in US 20110312394 (DESIGN TONG CO., LTD.).
Heat processable elastomeric polyurethanes comprising (per)fluoropoly-ether blocks were disclosed for example in U.S. Pat. No. 5,332,798 (AUSIMONT S.P.A.).
U.S. Pat. No. 4,540,765 (BAYER AKTIENGESELLSCHAFT) discloses a coating for textile fabrics and fibers, to render their surface repellent to oil and/or water. To this aim, a coating with polyurethane perfluoroalkyl ligands is provided. A final step comprising heating is performed to remove the end blocks and effects chemical surface onto on the surface. It is a matter of fact that this document discloses a coating (or finishing) for certain articles, wherein the coating is made from a composition comprising a polyurethane perfluoroalkyl compound, without however providing any disclosure or suggestion of any article made from such a polymer.
The Applicant perceived the need of providing a new polymeric material that can be useful for the manufacture of cases, notably for portable electronic devices, characterized by having improved properties when compared to hydrogenated thermoplastic polyurethane polymers (H-TPU), notably improved resistance to stain and finger-prints, chemical and wear resistance, low temperature flexibility, silky feel and mechanical properties.
Thus, in a first aspect, the present invention relates to a case configured to hold at least one part of a mobile media device, said case being made from a composition [composition (C)] comprising at least one fluorinated polyurethane [F-TPU polymer], said F-TPU polymer comprising recurring units derived from:
[monomer (a)] at least one diol selected from the group comprising poly-ether type diol, poly-ester type diol, polybutadien-diol and polycarbonate-diol;
[monomer (b)] at least one hydroxy-terminated (per)fluoropolyether polymer [PFPE polymer];
[monomer (c)] at least one aromatic, aliphatic or cycloaliphatic diisocyanate; and
[monomer (d)] at least one aliphatic, cycloaliphatic or aromatic diol having from 1 to 14 carbon atoms.
The Applicant has surprisingly found that the case made from said composition (C) show 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.
In addition, the Applicant surprisingly found that the case made from composition C as defined above shows improved resistance to stain and an increased ease of cleaning, when compared to panels made from hydrogenated thermoplastic polyurethane (H-TPU) polymers.
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, poly-caprolactone-diol and polycarbonate-diol being particularly preferred.
Preferably, said at least one monomer (b) is a hydroxy-terminated (per)fluoropolyether polymer [PFPE polymer], i.e. a 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
—O-D-(CFX#)z1-O(Rf)(CFX*)z2-D*-O—
wherein
z1 and z2, equal or different from each other, are equal to or higher than 1;
X# and X*, equal or different from each other, are —F or —CF3, provided that when z1 and/or z2 are higher than 1, X# and X* are —F;
D and D*, equal or different from each other, are an alkylene chain comprising from 1 to 6 and even more preferably from 1 to 3 carbon atoms, said alkyl chain being optionally substituted with at least one perfluoroalkyl group comprising from 1 to 3 carbon atoms;
(Rf) comprises, preferably consists of, repeating units R°, said repeating units being independently selected from the group consisting of:
(i) —CFXO—, wherein X is F or CF3;
(ii) —CFXCFXO—, wherein X, equal or different at each occurrence, is F or CF3, with the proviso that at least one of X is —F;
(iii) —CF2CF2CW2O—, wherein each of W, equal or different from each other, are F, Cl, H;
(iv) —CF2CF2CF2CF2O—;
(v) —(CF2)j—CFZ—O— wherein j is an integer from 0 to 3 and Z is a group of general formula —O—R(f-a)-T, wherein R(f-a) is a fluoropolyoxyalkene chain comprising a number of repeating units from 0 to 10, said recurring units being chosen among the following: —CFXO—, —CF2CFXO—, —CF2CF2CF2 O—, —CF2CF2CF2CF2O—, with each of each of X being independently F or CF3 and T being a C1—C3 perfluoroalkyl group.
More preferably, chain (Rf) is selected from the following formulae (Rf-a) to (Rf-c):
(Rf-a)—(CF2O)n(CF2CF2O)m(CF2CF2CF2O)p(CF2CF2CF2CF2O)q—
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;
(Rf-b)—(CF2CF(CF3)O)a(CF2CF2O)b(CF2O)c(CF(CF3)O)d—
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;
(Rf-c)—(CF2CF(CF3)O)e(CF2O)f(CF(CF3)O)g—
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-di-isocyanate (MDI), 1,6-hexan-diisocyanate (HDI), 2,4-toluene-diisocyanate, 2,6-toluene-diisocyanate, xylilen-diisocyanate, naphthalene-diisocyanate, paraphenylen-diisocyana- te, hexamaethylen-diisocyanate, isophorone-diisocyanate, 4,4′-dicyclohexyl-methane-diisocyanate and cyclohexyl-1,4-diisocyanate.
MDI and HDI 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 case according to the present invention 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.
According to a first embodiment, the case according to the present invention comprises a back panel and a plurality of sidewalls, preferably four sidewalls, extending from said back panel, such that the back panel and the sidewalls define a storage volume for and holding the portable device.
With reference to
According to a second embodiment, the case according to the present invention comprises peripheral edges, having an inner surface shaped for receiving and holding the edges of a portable device.
With reference to
According to a third embodiment, the case according to the present invention is in the form of one or more element, configured to be adapted to the corners of the portable electronic device.
With reference to
The case according to the present invention has mechanical properties is sufficiently stretchable and resilient such that even when stretched it returns towards its original shape.
According to a first embodiment, the case according to the present invention comprises only one layer [layer L1] made from composition C as defined above.
According to another preferred embodiment, the case according to the present invention comprises layer L1, having an internal surface and an external surface, wherein at least one surface, preferably the external surface, is coupled with a thermo-formed layer [layer 0] made from a hard plastic. Advantageously, said layer 0 contributes to the overall rigidity of the case and to the protection of the portable electronic device hold by the case.
The skilled person will understand that the case (100, 200, 300) according to the present invention can be manufactured in different shapes and/or dimensions, in order to hold portable electronic devices having different dimensions, such as for example smartphones, tablets and laptop computers.
The case according to the present invention can be manufactured following methods known in the art.
As an example, the case can be manufactured by a process comprising the following steps:
(i) providing a mould;
(ii) filling said mould with a composition comprising at least one elastomeric fluorinated polyurethane [F-TPU polymer] as defined above;
(iii) sealing the mould;
(iv) heat treating the sealed mould; and
(v) extracting the case from the mould.
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.
It will be apparent to the skilled person that the shape and the dimensions of the mould are not limitative and can be properly selected depending on the desired shape and dimension of the case.
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
Monomers (a):
(a1) CAPA™ 2201 (from Perstorp) polycaprolactone-diol (PLC) having molecular weight (Mw) of about 2,000 and —OH value of about 56 mg KOH/g;
(a2) polytetramethyleneglycol (PTMEG) having Mw of about 2,000
(a3) ETERNACOLL® UH200 (from UBE) polycarbonate-diol (PCD) having Mw of about 2,000
(a4) BESTER™ (from DOW) polyester-diol having Mw of about 2,000
Monomers (b) having formula:
H(OCH2CH2)pOCH2CF2O(CF2CF2O)m(CF2O)nCF2CH2O(CH2CH2O)pH
(b1) p=4.7 and Mw of about 2,000
(b2) p=1.6 and Mw of about 1,700
Monomers (c):
(c1) diphenylen-4,4′-diisocyanate (MDI)
(c2) 1,6-hexan-diisocyanate (HDI)
Monomers (d):
(d1) 1,4-butanediol (BDO)
(d2) 1,6-hexandiol (HDO)
Catalyst:
bismuth neodecanoate
Preparation of F-TPU Polymer Specimens—Method A
F-TPU polymer specimens 1 to 4 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 8 in the form of sheet were prepared as follows:
the hydrogenated pre-polymer was synthetized by reacting monomer (c) and monomer (a) in the equivalent ratio 2 to 1, at a temperature of 90° C.;
the fluorinated pre-polymer was synthetized by reacting monomer (c) and monomer (b) in the equivalent ratio 2 to 1, at a temperature of 90° C.;
the hydrogenated pre-polymer and the fluorinated pre-polymer were then mixed together and stirred at 90° C. for 30 minutes;
monomer (c) was further added depending on the selected stoichiometry;
the reaction was continued at 90° C. for 3 minutes until chain-extension was completed;
the polymer thus obtained was casted at 100° C. for 24 hours.
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 case for portable electronic devices, and hence F-TPU polymers provide good mechanical properties to the case.
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 (SFE) 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:
cycle speed: 30 cycles/min
stroke length: 2.54 cm (1 inch)
number of cycles: 200
total load: 1 kg.
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:
after rub and
after cleaning with isopropyl-alcohol (IPA).
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:
++=no stain
+=mark/halo
−=stain
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 the
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 polymers.
| Number | Date | Country | Kind |
|---|---|---|---|
| 16178298.2 | Jul 2016 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2017/066584 | 7/4/2017 | WO | 00 |
