OXAZOLIDINEDIONE-TERMINATED PREPOLYMER

Abstract

The present invention relates to a compound obtained by a process comprising the following steps: (i) Reacting at least one isocyanate containing compound, in stoichiometric excess, with a first isocyanate-reactive compound having a number average molecular weight lower than 400, resulting in the formation of at least one prepolymer, (ii) Reacting said prepolymer, in stoichiometric excess, with a second isocyanate-reactive compound having a number average molecular weight equal to or higher than 400, resulting in the formation of a modified prepolymer, (iii) Reacting said modified prepolymer with a hydroxyl-ester compound or a hydroxyl-acid compound with the formation of hydroxyl-ester terminated prepolymer or hydroxyl-acid terminated prepolymer, and Ring-closing said hydroxyl-ester terminated prepolymer or hydroxyl-acid terminated prepolymer; (iv) Formation of said compound made of oxazolidinedione-terminated prepolymer and oxazolidinedione-terminated monomer, which is soluble in said oxazolidinedione-terminated prepolymer.

Claims

1. A compound obtained by a process comprising the following steps: (i) Reacting at least one isocyanate containing compound, in stoichiometric excess, with a first isocyanate-reactive compound having a number average molecular weight lower than 400, resulting in the formation of at least one prepolymer having hard blocks in its structure, (ii) Reacting said prepolymer, in stoichiometric excess, with a second isocyanate-reactive compound having a number average molecular weight equal to or higher than 400, resulting in the formation of a modified prepolymer having soft blocks and hard blocks in its structure, which modified prepolymer contains unreacted isocyanate monomer (iii) Reacting said modified prepolymer with a hydroxyl-ester compound or a hydroxyl-acid compound with the formation of hydroxyl-ester terminated prepolymer or hydroxyl-acid terminated prepolymer, and Ring-closing said hydroxyl-ester terminated prepolymer or hydroxyl-acid terminated prepolymer, and (iv) forming of said compound made of oxazolidinedione-terminated prepolymer and oxazolidinedione-terminated monomer, which is soluble in said oxazolidinedione-terminated prepolymer.

2. The compound according to claim 1, wherein said at least one isocyanate containing compound and said first isocyanate-reactive compound are reacted at a molar ratio (NCO:OH) ranging 1.05 to 200, preferably to 1.5 to 200.

3. The compound according to claim 1, wherein said prepolymer and said second isocyanate-reactive compound are reacted at a molar ratio (NCO:OH) ranging from 0.5 to 1.2.

4. The compound according to claim 1, wherein said at least one prepolymer has an NCO value ranging from 10% to 40%, preferably from 20% to 25%.

5. The compound according to claim 1, wherein said modified prepolymer has an NCO value ranging from 0.5% to 35%.

6. The compound according to claim 1, wherein step (iii) is performed at a first temperature ranging from 50° C. to 100° C. resulting in the formation of a hydroxyl-ester terminated prepolymer or a hydroxyl-acid terminated prepolymer.

7. The compound according to claim 6, wherein step (iii) is carried out, at said first temperature, in a catalyst free condition.

8. The compound according to claim 6, wherein step (iii) comprises a ring-closure step by processing said hydroxyl-ester terminated prepolymer or a hydroxyl-acid terminated prepolymer in the presence of at least one catalyst, at a second temperature, which is preferably higher than the first temperature, resulting in the formation of oxazolidinedione-terminated prepolymer and oxazolidinedione-terminated monomer.

9. The compound according to claim 1, wherein said at least one prepolymer has a hard block content of at least 80 wt. %.

10. The compound according to claim 1, wherein said modified prepolymer has a hard block content ranging from 2 to 25 wt.

11. The compound according to claim 1, wherein said compound formed in step (iv) has a hard block content ranging from 10 to 15 wt. %.

12. A poly(urethane-amide) compound obtained by reacting a compound according to claim 1, with at least one amine compound having a functionality of at least 1.8.

13. A product comprising poly(urethane-amide) compound according to claim 12.

Description

EXAMPLES OF THE INVENTION

[0122] The examples described hereunder illustrate some embodiments of the present invention. Unless otherwise indicated, all parts and all percentages in the following examples, as well as throughout the specification, are parts by weight or percentages by weight respectively.

Example 1

1. Preparation of the Modified Prepolymer—Scheme A

[0123] 250 g of SUPRASEC®2021 (glycol-based diols having a number average molecular weight lower than 400; 0.69 mol, NCOv equal to 23.2%) were weighed out in a round bottomed vessel equipped with mechanical stirrer, digital thermocouple, and water-cooled condenser. The temperature was raised to 70° C. under nitrogen flux. When the reaction temperature was reached, the prepolymer is then reacted with 232.5 g of PPG (Mw=2000 g/mol, OHv=56 mg KOH) (0.5 mol), which were added drop wise to the reaction vessel with a pressure equalized addition funnel under vigorous stirring. The addition rate was controlled, in order to maintain a constant temperature inside the reactor. After the complete addition of PPG 2000, about 6 g of product were sampled to determine the NCO value of the modified prepolymer and to monitor the advancement of the reaction. When the desired NCOv was reached (=10%±0.05%, determined via potentiometric titration as described above under methods), the modified prepolymer, which contains some unreacted MDI, was transferred into metal tins and stored under inert atmosphere at room temperature. The modified prepolymer has a final hard block content of 51.81%.

[0124] The hardblock (HB) content (fragments having less than 400 g/mol) was calculated using the following formula:

HB=100×(wt isocyanate+wt chain extender+wt H.sub.2O**−wt CO.sub.2**−wt ethanol)/(wt isocyanate+wt chain extender−wt H.sub.2O**−wt CO.sub.2**−wt ethanol+wt polyol*).

*wt polyol >400 g/mol: soft block only; wt polyol/chain extender <500 g/mol: hardblock.**if no water is added, wt H.sub.2O and wt CO.sub.2 become zero.

##STR00002##

2. Reaction with Ethyl Lactate

[0125] 250 g (0.3 mol) of the prepared modified prepolymer (NCOv equal to about 10%) of section 1 above (SUPRASEC®2021 modified with PPG 2000) were weighted out in a round bottomed flask equipped with mechanical stirrer, digital thermocouple, and condenser. The temperature was raised to 70° C. under nitrogen blanket. When the reaction temperature was reached, an equivalent amount of ethyl lactate, 70.32 g (0.6 mol) was added drop wise to the reaction vessel under mechanical stirring. The viscosity of the mixture (ethyl lactate-terminated prepolymer, which contains ethyl lactate-terminated monomer) was observed, in order to increase, together with the conversion of isocyanate groups to urethane groups. The reaction was followed via infrared spectroscopy analyzing a sample every 30 minutes and monitoring the disappearance of peak associated to the isocyanate groups at 2270 cm-1. When the reaction was completed, the product was transferred into glass bottles and stored under inert atmosphere at ambient temperature.

[0126] The ethyl lactate-terminated prepolymer has a final hard block content of 62.38%.

[0127] The hardblock (HB) content was calculated using the following formula:

HB=100×(wt isocyanate+wt chain extender+wt ethyl lactate+wt H.sub.2O**−wt CO.sub.2**−wt ethanol)/(wt isocyanate+wt chain extender+wt ethyl lactate+wt H.sub.2O**−wt CO.sub.2**−wt ethanol+wt polyol*).

*wt polyol >400 g/mol: soft block only; wt chain extender/polyol <400 g/mol: hardblock.**if no water is added, wt H.sub.2O and wt CO.sub.2 become zero.

3. Synthesis of the Compound of the Present Invention—Ring Closure Step

[0128] Under the same condition as indicated for the reaction with ethyl lactate. The reaction product obtained in the above-mentioned step was poured into a 3-neck flask equipped with a Dean-Stark apparatus, thermocouple and mechanical stirrer. DABCO was added (0.05% by weight) and the temperature was raised to 100° C. The intramolecular reaction promotes the formation of ethanol that is distilled out of the reaction vessel. The reaction was monitored via FT-IR following the appearance of a new peak at 1816 cm.sup.1, associated to the stretching of the N—CO bonds in strained rings, the disappearance of the peak at 1726 cm-1 of the esteric C═O in favour of an increased broad peak at 1742 cm-1. When the reaction was completed, the final product was collected in glass bottles without further purification and stored under nitrogen atmosphere.

[0129] The compound consists in oxazolidinedione-terminated prepolymer and oxazolidinedione-terminated monomer, where it has been visually observed that oxazolidinedione-terminated monomer is soluble in oxazolidinedione-terminated prepolymer. In this way, the final product is a compound in liquid state.

[0130] The oxazolidinedione-terminated prepolymers prepared contained no NCO groups (content below detection limit, as measured by quantitative GC analysis).

[0131] The final compound has a final hard block content of 58.86 wt. %.

[0132] The hardblock (HB) content was calculated using the following formula:

HB=100×(wt isocyanate+wt chain extender+wt ethyl lactate+wt H.sub.2O**−wt CO.sub.2**−wt ethanol)/(wt isocyanate+wt chain extender+wt ethyl lactate+wt H.sub.2O**−wt CO.sub.2**−wt ethanol+wt polyol*).

*wt polyol >400 g/mol: soft block only; wt chain extender/polyol <400 g/mol: hardblock.**if no water is added, wt H.sub.2O and wt CO.sub.2 become zero.

##STR00003##

4. Synthesis of Poly(Urethane-Amide) Compound

[0133] Polymerization of the product obtained in example 1 with amine(s) was carried out as indicated below (see scheme C hereunder).

[0134] 50 g of the compound of example 1 were weighed out in a disposable glass bottle and heated up to 100° C. under nitrogen blanket. When the viscosity decreased, the compound was stirred with a mechanical mixer. When the reaction temperature was reached, an equimolar amount of primary amine(s) was added (the exact quantities are listed in table 1 below). The mixture was homogenized for 20 seconds and transferred into a mould, pre-heated at 100° C., and allowed to cure for 1 hour.

[0135] Please note that different types of amine(s) can be used, as illustrated in table 1 below, including mixtures thereof.

[0136] Table 1 below illustrate a first embodiment of example 1 (sample number 1), when compound is reacted with ECA-29 and Elastamine HT 1100 at a certain amount respectively, and a second embodiment, when the compound of example 1 is reacted with ECA-29 and Elastamine HT 1100 in amounts, as indicated below.

TABLE-US-00001 TABLE 1 FINAL POLYMER SAMPLE COMPOUND OF THE INVENTION AMINES HARDBLOCK NUMBER S2021/PPG 2000 FINAL 50 G 0.049 MOL ECA-29  9.21 G 0.034 MOL 51% 1 NCOv 10% ELASTAMINE 16.50 G 0.015 MOL HT 1100 S2021/PPG 2000 FINAL 50 G 0.049 MOL ECA-29 12.47 G 0.046 MOL 64% 2 NCOv 10% ELASTAMINE  3.30 G 0.003 MOL HT 1100

##STR00004##

5. Mechanical Properties

Example 1

[0137] The cured polymers were cut into “dog bone” specimen in order to evaluate their tensile mechanical properties. The selected geometry has a cross section of 4×2 mm. The specimens were strained at 100 mm/min with an Instron device (ISO DIN53504). The results are shown in table 2.

[0138] Table 2 here below illustrates mechanical properties of the poly(urethane-amide) of example 1, according to the first and second embodiment.

TABLE-US-00002 TABLE 2 Hard block Young's Elongation Stress content in % modulus at break at break Product (after cure) (kPa) (%) (kPa) Poly(urtheane-amide) 51 1415 971 911 compound_sample 1 of example 1 Poly(urtheane-amide) 64 3251 175 1334 compound_sample 2 of example 1

Example 2

[0139] All the aforementioned conditions and compounds were applied for example 2, except that the modified prepolymer of example 2 was obtained by using 106.82 g of PPG 2000 with 250 g of SUPRASEC®2021, in order to obtain a final NCOv of about 15%. Moreover, the final hard block content of such modified prepolymer was 70.06%.

[0140] Moreover, the modified prepolymer of example 2 is reacted with ethyl lactate as indicated above, resulting in the formation of the compound of the invention, which is then further reacted with amine (table 3 below), according to a first (sample number 3), second (sample number 4) and third (sample number 5) embodiments of example 2.

TABLE-US-00003 TABLE 3 OXAZOLIDINEDIONE-TERMINATED FINAL POLYMER SAMPLE PREPOLYMER AMINES HARDBLOCK NUMBER S2021/PPG 2000 FINAL 50 G 0.071 MOL ECA-29 11.11 G 0.041 MOL 52% 3 NCOv 15% ELASTAMINE 33.00 G 0.030 MOL HT 1100 S2021/PPG 2000 FINAL 50 G 0.071 MOL ECA-29 14.91 G 0.055 MOL 64% 4 NCOv 15% ELASTAMINE 17.60 G 0.016 MOL HT 1100 S2021/PPG 2000 FINAL 50 G 0.071 MOL ECA-29 19.24 G 0.071 MOL 83% 5 NCOv 15%

Mechanical Properties

Example 2

[0141] The cured polymers were cut into “dog bone” specimen in order to evaluate their tensile mechanical properties. The selected geometry has a cross section of 4×2 mm. The specimens were strained at 100 mm/min with an Instron device (ISO DIN53504). The results are shown in table 4.

[0142] Table 4 here below illustrates mechanical properties of the poly(urethane-amide) of example 2, according to the first and second embodiments.

TABLE-US-00004 TABLE 4 Hard block Young's Elongation Stress content modulus at break at break Product (%) (kPa) (%) (kPa) Poly(urethane-amide) 52 200 298 88 compound- sample 3 of example 2 Poly(urethane-amide) 64 1112 19 1077 compound- sample 4 of example 2

[0143] For all of the above-mentioned examples and embodiments, the obtained polymers did not need any purification and could be synthesized with different hard block contents by combining different amines.

COMPARATIVE EXAMPLE 1

[0144] 300 g of xylenes were added to a 500 mL three-neck, round bottom flask. This flask was dropped into a 75° C. oil bath and an overhead stirring apparatus was attached. 150 mg (0.1 wt %) of DABCO catalyst and 75 g ethyl lactate were then added to this solution. Finally, 75 g of RUBINATE 44, from a ‘melted out’ stock supply in an 80° C. oven, was poured into an addition funnel connected to one of the flask's necks. A heat gun was used to prevent RUBINATE 44 recrystallization. The addition funnel's contents were then added drop wise over a 15-minute period. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (from Thermo Fisher Scientific) was used to track the intensity reduction of the isocyanate peak, seen at approximately 2250 cm-1. Significant reduction was seen after 2.25 hours. At that point, the flask was removed from the oil bath and allowed to cool to room temperature. During this cooling, precipitation occurred resulting in the formation of a white solid. This could be promoted by placing the flask in an ice bath to further decrease the product's solubility in xylenes. The product was isolated by vacuum filtration over a three-day period.

[0145] Then, 13.8 g of JEFFAMINE D2000 and 11.1 g of JEFFAMINE D400 (from Huntsman) were poured into an 8 oz. jar making a 2:8 blend. The jar was then placed in a 100° C. oil bath and an overhead mixing apparatus was established. Afterwards, 0.41 mL tin octoate catalyst (a 1.25 wt % loading) was added to the blend. Finally, 16 g of the urethane-ester synthesized above (Rubinate 44/Ethyl Lactate adduct) was added. The (poly) urethane-amide compound was formed by stirring and heating the reactive mixture for a period of five hours.

[0146] Table 5 hereunder indicates the types of products used in the examples of the present invention.

TABLE-US-00005 TABLE 5 CHEMICAL NAME TRADE NAME CAS SUPPLIER CHEMICAL STRUCTURE OF KEY COMPONENTS Poly(propylene glycol) (PPG 2000) Mw 2000 g/mol Acclaim 2200 25322-69-4 Covestro [00005] Diphenylmethane 4,4′- SUPRASEC ® N.A Huntsman diisocyanate/TPG- 2021 diolmix prepolymer (chain extender/polypol with Mn below 400 g/mol) Ethyl Lactate Ethyl Lactate 687-47-8 Sigma- Aldrich [00006] 1,4-Diazabicyclo[2.2.2]- octane DABCO 280-57-9 Sigma- Aldrich [00007] Polyethylenepolyamine: chain extender molecular weight MW below 400 g/mol (about 271 g/mol) ECA-29 68131-73-7 Huntsman [00008] Polyetrahydrofuran diamine Elastamine HT 1100 72088-96-1 Huntsman [00009]

[0147] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to a person skilled in the art from this disclosure, in one or more embodiments. Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the appended claims, any of the claimed embodiments can be used in any combination.

[0148] As used herein, the singular forms “a”, “an”, and “the” include both singular and plural referents unless the context clearly dictates otherwise. By way of example, “an isocyanate group” means one isocyanate group or more than one isocyanate group.

[0149] The terms “comprising”, “comprises” and “comprised of” as used herein are synonymous with “including”, “includes” or “containing”, “contains”, and are inclusive or open-ended and do not exclude additional, non-recited members, elements or method steps. It will be appreciated that the terms “comprising”, “comprises” and “comprised of” as used herein comprise the terms “consisting of”, “consists” and “consists of”. This means that, preferably, the aforementioned terms, such as “comprising”, “comprises”, “comprised of”, “containing”, “contains”, “contained of”, can be replaced by “consisting”, “consisting of”, “consists”.

[0150] Throughout this application, the term “about” is used to indicate that a value includes the standard deviation of error for the device or method being employed to determine the value.

[0151] As used herein, the terms “% by weight”, “wt %”, “weight percentage”, or “percentage by weight” are used interchangeably.

[0152] The recitation of numerical ranges by endpoints includes all integer numbers and, where appropriate, fractions subsumed within that range (e.g. 1 to 5 can include 1, 2, 3, 4 when referring to, for example, a number of elements, and can also include 1.5, 2, 2.75 and 3.80, when referring to, for example, measurements). The recitation of end points also includes the end point values themselves (e.g. from 1.0 to 5.0 includes both 1.0 and 5.0). Any numerical range recited herein is intended to include all sub-ranges subsumed therein.

[0153] All references cited in the present specification are hereby incorporated by reference in their entirety. In particular, the teachings of all references herein specifically referred to are incorporated by reference.

[0154] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0155] Throughout this application, different aspects of the invention are defined in more detail. Each aspect so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature indicated as being preferred or advantageous may be combined with any other feature or features indicated as being preferred or advantageous.

[0156] Although the preferred embodiments of the invention have been disclosed for illustrative purpose, those skilled in the art will appreciate that various modifications, additions or substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.