FLAME RETARDANT PREPOLYMER COMPOSITION, FLAME RETARDANT POLYMER COMPOSITION, AND THEIR MANUFACTURING METHODS AND USES

Abstract

A flame retardant prepolymer composition for use in a flame retardant polymer includes at least one isocyanate-terminated polyurethane prepolymer containing at least one phosphonate oligomer, phosphonate monomer or a mixture thereof in an amount of from 5 to 75 parts by weight, referring to the total amount of the at least one isocyanate-terminated polyurethane prepolymer. The at least one phosphonate oligomer, phosphonate monomer or a mixture thereof contains units according to the following structural formula (I) of the description in which n is an integer from 1 to 20, R is a C.sub.1-20 alkyl, C.sub.2-20 alkene, C.sub.2-20 alkyne, C.sub.3-20 cycloalkyl, or C.sub.6-20 aryl, and R2 is an aliphatic and/or aromatic group, wherein a NCO value is in a range between approximately 2% to approximately 10% obtained by titration against a dibutylamine/tolulene solution as per ISO 14896: 2009-07 Method A.

Claims

1. A flame retardant prepolymer composition comprising at least one isocyanate terminated polyurethane prepolymer wherein the at least one isocyanate-terminated polyurethane prepolymer is prepared by at least one diol and/or at least one polyol, and at least one isocyanate, and contains at least one phosphonate oligomer, phosphonate monomer or a mixture thereof in an amount of from 5 to 75 parts by weight, referring to the total amount of the at least one isocyanate-terminated polyurethane prepolymer, wherein the at least one phosphonate oligomer, phosphonate monomer or a mixture thereof contains units according to the following structural formula: ##STR00003## in which n is an integer from 1 to 20, R is a C.sub.1-20 alkyl, C.sub.2-20 alkene, C.sub.2-20 alkyne, C.sub.3-20 cycloalkyl, or C.sub.6-20 aryl, and R2 is an aliphatic and/or aromatic group, wherein a NCO value is in a range between 4.1%±20% to 6.4%±20% obtained by titration against a dibutylamine/tolulene solution as per ISO 14896: 2009-07 Method A, wherein the NCO value defines the percentage of free isocyanate groups of the at least one isocyanate-terminated polyurethane prepolymer in the flame retardant prepolymer composition.

2. The flame retardant prepolymer composition according to claim 1, further comprising at least one non-aqueous solvent.

3. The flame retardant prepolymer composition according to claim 1, wherein n is from 1 to 10, and R2 is an aromatic group.

4. The flame retardant prepolymer composition according to claim 1, wherein R is a methyl group.

5. The flame retardant prepolymer composition according to claim 1, wherein the phosphonate oligomer used in the preparation of the at least one isocyanate-terminated polyurethane is a phosphonate diol selected from the group consisting of a random co-oligo(phosphonate carbonate), a block co-oligo(phosphonate carbonate), a random co-oligo(phosphonate ester), a block co-oligo(phosphonate ester) or any mixture thereof.

6. The flame retardant prepolymer composition according to claim 1, wherein the phosphonate oligomer building block has a structure according to one of the following formulae: ##STR00004## in which R1 and R2 are aliphatic or aromatic hydrocarbons, and n is an integer from 1 to 20.

7. The flame retardant prepolymer composition according to claim 1, wherein the phosphonate oligomer used in the preparation of the at least one isocyanate-terminated polyurethane is a copolymer of bisphenol-A and diphenyl methyl phosphonate.

8. The flame retardant prepolymer composition according to claim 1, wherein the at least one isocyanate-terminated polyurethane prepolymer is obtained by using at least one diol and/or at least one polyol, whereby the diol and the polyol are selected from a group comprising polyetherglycols, polyester diols, polycarbonates, polytetrahydrofurans, dimer diols, fatty acids, dimerized fatty acid based diols and/or (BES: biobased) polyester based diols in the manufacturing process of the at least one isocyanate-terminated polyurethane prepolymer.

9. The flame retardant prepolymer composition according to claim 8, wherein the at least one diol and/or at least one polyol is a multifunctional diol selected from the group comprising trifunctional diols, branched diols with an at least one hydroxyl group and an at least one carboxyl group, linear polyethylene glycol ether diols or a mixture of at least two of them.

10. The flame retardant prepolymer composition according to claim 8, wherein the polyester diol is obtained by a reaction of at least one lactone and at least one diol.

11. The flame retardant prepolymer composition according to claim 10, wherein the at least one lactone is e-caprolactone.

12. The flame retardant prepolymer composition according to claim 10, wherein the at least one diol is a polyester polyol.

13. A flame retardant polyurethane urea composition obtained from the flame retardant prepolymer composition according to claim 1 by reacting the flame retardant prepolymer composition in at least one cross-linking step with at least one crosslinking agent selected from a group comprising diamines, triamines, organic aminosilanes and/or carbodiimides.

14. The flame retardant polyurethane urea composition according to claim 13, wherein the at least one diamine and/or triamine is selected from a group comprising alkyldiamines and alkyltriamines.

15. The flame retardant polyurethane urea composition according to claim 13, wherein at least one neutralization step is carried out before the at least one crosslinking step.

16. The flame retardant polyurethane urea composition according to claim 15, wherein at least one neutralization step is carried out by using at least one neutralizing agent selected of a group comprising tertiary amines, amino alcohols, metal hydroxides, ammonia or a mixture thereof.

17. The flame retardant polyurethane urea composition according to claim 13, wherein in the at least one crosslinking step, before the at least one crosslinking step, or after the at least one crosslinking steps, water is added in order to obtain a polyurethane composition dispersion.

18. A method for manufacturing a flame retardant prepolymer composition according to claim 1, comprising: mixing at least one phosphonate oligomer, at least one polyether glycol, at least one diol and/or at least one polyol with at least one non-aqueous solvent, and heating said solution to a temperature in a range from 30° C.±20% to 100° C.±20%; adding at least one isocyanate in excess to relation to the total amount of the at least one polyetherglycol, at least one diol and/or at least one polyol; and heating the obtained solution to a temperature in a range from 65° C.±20% to 96° C.±20% until a NCO value is in a range between 4.1%±20% to 6.4%±20%, obtained by titration against a dibutylamine/tolulene solution as per ISO 14896: 2009-07 Method A, wherein the NCO value defines the percentage of free isocyanate groups of the at least one iso-cyanate-terminated polyurethane prepolymer in the flame retardant prepolymer composition.

19. The method for manufacturing a flame retardant polyurethane urea composition according to claim 13, comprising: providing a flame retardant prepolymer composition; adding water to obtain a polyurethane dispersion; and adding at least one crosslinking agent.

20. The method for manufacturing a flame retardant polyurethane urea composition according to claim 19, whereby the non-aqueous solvent is evaporated in order to obtain an aqueous isocyanate-terminated polyurethane composition.

Description

DETAILED DESCRIPTION

[0063] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.

[0064] The present disclosure will be described hereunder in more detail with reference to the following non-limiting examples in accordance with the present disclosure of the flame retardant prepolymer composition and the flame retardant polyurethane urea composition.

[0065] The pH value is detected with a pH meter set model pH50+DHS−COND51+−PC52+DHS at 50° C. The products are measured with a dilution of 1:9 in water. The Calibration standards were a pH buffer solution with a pH of 4.01±0.02 at 25° C. and a pH buffer solution with a pH of 7.00±0.02 at 25° C.

[0066] The viscosity was measured with a Brookfield DV2T EXTRA™ Viscometer. The viscosity was measured at 20° C. with rotational frequency of 20 rpm and a spindle 2 of the RV EZ-Lock Spindle Set.

[0067] The non-volatile content, also known as active content, was measured with a Sartorius balance. 0.5 to 2.0 g of the inventive flame retardant polyurethane urea composition was poured on a filter paper made of Fiber Glass Filter and a diameter of 90 mm in a disposable aluminum Sample Pan with a diameter of 90 mm and a height of 7 mm and heated to 120° C. for 30 min. The weight before m.sub.wet and the weight after heating m.sub.dry was detected. By calculating as set forth below, the weight percent of the non-volatile content could be determined by:

[00005]$\text{non-}\mathrm{volatile}\mathrm{content}\left[\mathrm{wt}-\%\right]=\frac{m_{\mathrm{dry}}}{m_{\mathrm{wet}}}.Math.100\%.$

[0068] The theoretical NCO value and the experimental NCO value were calculated as described above according to ISO 14896: 2009-07 Method A.

[0069] The fire performance measurements were carried out on the basis of the results obtained with the five test specimens each on paper and cellulose cloth comparable to the UL 94 VTM (Vertical flame test of thin materials: ASTM D4804). In this test, the tested materials are given test results comparable to the classifications of UL-94 VTM-0, UL-94 VTM-1 and UL-94 VTM-2. Briefly, the criteria for each of these UL-94-VTM-classifications are as follows:

TABLE-US-00001 TABLE 1 Inflammability classification according to UL 94 VTM Testing criteria VTM-0 VTM-1 VTM-2 After-burning time of each sample [s] ≤10 ≤30 ≤30 (after the 1st and 2nd flame treatment) Total of all after-burning times [s] ≤50 ≤250 ≤250 (10 flame treatments) Afterburning time plus afterglow time after ≤30 ≤60 ≤80 2nd flame treatment [s] Burning dripping no no yes (inflammation of the cotton wool) Burn to the retaining clip no no no (complete destruction of the sample)

[0070] To judge the flame retardant effect of inventive flame retardant polyurethane urea composition coated fabrics were manufactured by using a paper or cellulose cloth which was impregnated with the inventive flame retardant polyurethane urea composition and dried at room temperature for 24 h. In order to assess the flammability of the flame retardant polyurethane urea composition itself, a thin film of dried flame retardant polyurethane urea composition was prepared for the flammability test comparable to UL 94 by drying the flame retardant polyurethane urea composition at room temperature. The samples were treated with a flame having a height of about 20 mm for 3 seconds, after a 10 sec break the flame treatment was repeated for again 3 sec.

[0071] The following compounds were used in the preparation of the composition of Example 1, Example 2, Comparative example 3 and Table 2.

[0072] Polyol derived from ε-caprolactone as a white paste with a viscosity at 60° C. of 150 mPA*s and a molecular weight of 1000 g/mol obtainable as CAPA 2101 from Ingevity was used. Dimethylol propionic acid powder having a purity of 95-100% from Perstorp was used. Trimethylol propane flakes with a hydroxy number of 1238-1260 mg KOH/g from Perstrop was used. Phosphonate oligomer powder with an ignition temperature of 590 to 600° C. obtainable as Nofia OL 1001 from FRX Polymers was used. Acetone with a purity of 98.5% from Panreac was used. Isophorone diisocyante obtainable as Vestanat IPDI from Evonik was used. Triethylamine with a purity of 99% from Alfa Aesar was used. As crosslinking agent γ-aminopropyl triethoxysilane with purity above 97% obtainable as Genosil GF 93 silane from Wacker Silicones was used. Ethylene diamine with a purity of 99% from Alfa Aesar was used.

Example 1: Preparation of Flame Retardant Prepolymer Composition

[0073] The following raw materials 401.7 g of polyol, 47.1 g of dimethylol propionic acid (Bis-MPA), 21 g of trimethylol propane (TMP) and 164.6 g of phosphonate oligomer were charged into a round bottom flask equipped with a thermometer, an agitator and a condenser. Add 60 g of acetone to the polyol mixture. Heat the polyol mixture to 85-90° C. under good agitation. Before adding 365.5 g of isophorone diisocyante under stirring the polyol mixture was cooled down to 55° C. When the exothermic reaction has subsided the reaction mixture was heated to 75-80° C. for 2 hours. When the reaction mixture reached the theoretical NCO value of 4.55%, cool the reaction mixture down to 60-65° C. The NCO value is determined by the di-n-butylamine titration method A. After reaching the temperature of 60-65° C., 28 g of triethylamine for neutralization of the reaction mixture was added and the temperature was maintained for 20-30 min. 140 g of acetone was poured to the reaction mixture to reduce the viscosity of the gained flame retardant prepolymer composition.

Example 2: Preparation of the Flame Retardant Polyurethane Urea Composition

[0074] The flame retardant prepolymer composition was transferred into a plastic container containing 1300 g cold water under high-speed mixing. The addition of flame retardant prepolymer composition into the cold water was completed within 15 min. Once the addition was complete, 11.8 g of crosslinking agent diluted with 100 g deionized water was added. After 5 min subsequently a solution of 32 g ethylene diamine with 100 g deionized water was poured into the reaction mixture within 5-10 min. The reaction mixture was stirred with a stirring rate of 500 to 800 rpm for about 2-3 h. When the reaction time was over, the reaction mixture was filtered through a 70-100 micron filter and acetone was distilled off under reduced pressure to obtain an organic solvent free flame retardant polyurethane urea composition. Filtering the flame retardant polyurethane urea composition by using a 100-micron polyester filter bag gave the desired flame retardant polyurethane urea composition.

Comparative Example 3: Preparation of a Comparative Polyurethane Composition without Fire Performance

[0075] The following raw materials 978.2 g of polyol based on polyester and 79.9 g of dimethylol propionic acid (Bis-MPA) were charged into a round bottom flask equipped with a thermometer, an agitator and a condenser. 120 g of acetone was added to the polyol mixture. The polyol mixture was heated to 75-80° C. under agitation. The polyol mixture was cooled down to 55° C. then 544.2 g of isophorone diisocyante was added under stirring. When the exothermic reaction subsided the reaction mixture was heated to 75-80° C. for 2 hours. When the reaction mixture reached the theoretical NCO value of 4.55%, cool the reaction mixture down to 60-65° C. The NCO value is determined by the di-n-butylamine titration method A. After reaching the temperature of 60-65° C., 48.2 g of triethylamine for neutralization of the reaction mixture was added and the temperature was maintained for 20-30 min. 120 g of acetone was poured to the reaction mixture to reduce the viscosity of the gained prepolymer composition. The prepolymer composition was transferred into a plastic container containing 1519 g cold water under high-speed mixing. The addition of prepolymer composition into the cold water was completed within 15 min. Subsequently a solution of 48.1 g ethylene diamine with 747 g deionized water was poured into the reaction mixture within 5-10 min. The reaction mixture was stirred with a stirring rate of 500 to 800 rpm for about 2-3 h. When the reaction time was over, the reaction mixture was filtered through a 70-100 micron filter and acetone was distilled off under reduced pressure to obtain an organic solvent free polyurethane composition. Filtering the polyurethane composition by using a 100-micron polyester filter bag gave the desired comparative polyurethane composition.

[0076] The experimental results of the flame retardant polyurethane composition were shown in the following Table 2.

TABLE-US-00002 TABLE 2 Comparison of the inventive example 2 and the comparative example 3 Parameters Example 2 Comparative example 3 pH value 8.21 pH 8.63 pH Viscosity, 20 C 190 mPa * s 164 mPa * s Non-volatile 40 wt-% 40 wt-% content Fire Paper; After-burning time of Paper: Burn to the Performance: each sample <10 sec after the retaining dip holding 1st flame treatment; after the the sample; 2nd flame treatment one out burning dripping of five samples started (inflammation of the burning (Total of all cotton wool) after-burning times <50 sec); Cellulose Cloth: Burn no burning dripping to the retaining Cellulose Cloth: After- clip holding burningtime of each sample the sample; burning <10 sec; no burning dripping dripping (inflammation of the cotton wool)

[0077] From the above results, it was shown that the flame retardant polyurethane urea composition achieved flame retardancy comparable to the class UL-94 VTM-0 respectively UL-94 VTM-1 of the UL 94 flammability testing standards.

[0078] Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.

[0079] As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

[0080] The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.