Composition that is suitable for producing polyurethane foams and that contains at least one nucleating agent

Abstract

Disclosed herein is a method for producing polyurethane or polyisocyanurate foams. The method involves reacting a composition (Z1) with at least one polyisocyanate, and occurs in the presence of at least one nucleating agent and a blowing agent, in which the nucleating agent and the blowing agent are mixed to obtain a composition (Z2) that is added to the composition (Z1) before it is reacted with the at least one polyisocyanate. The composition (Z1) contains (i) 100 parts by mass of a composition (ZP) including at least one polyol and at least one catalyst that catalyzes formation of a urethane, urea or isocyanuarate bond, and (ii) from 0.05 to 10 parts by mass of a surfactant TD having an HLB value below 6 and no silicon atom.

Claims

1. A method of producing polyurethane or polyisocyanurate foams, the method comprising: (a) forming a composition (Z1) by adding a surfactant TD, having an HLB value below 6 and no silicon atom, to a composition (ZP) comprising at least one polyol and at least one catalyst that catalyzes formation of a urethane, urea or isocyanurate bond; and (b) reacting the composition (Z1) with at least one polyisocyanate, to obtain a polyurethane foam or a polyisocyanurate foam, wherein: from 0.05 to 10 parts by mass of the surfactant TD are added per 100 parts by mass of the composition (ZP); the reacting occurs in the presence of at least one nucleating agent selected from the group consisting of a perfluorinated hydrocarbon, an ether having at least one perfluorinated hydrocarbyl moiety and a ketone having at least one perfluorinated hydrocarbyl moiety, and a blowing agent, wherein the nucleating agent differs from the blowing agent; and the nucleating agent and the blowing agent are mixed to obtain a composition (Z2) that is added to the composition (Z1) to obtain a composition (ZS) before the reacting with the at least one polyisocyanate, wherein after composition (Z2) is added to composition (Z1) and prior to the reacting with the at least one polyisocyanate, the composition (ZS) is stabilized such that said composition (ZS) is clear and devoid of any droplet formation or clouding as perceivable by the naked eye, and wherein the surfactant TD is isotridecanol or isononanol.

2. The method according to claim 1, wherein the surfactant TD is isotridecanol.

3. The method according to claim 1, wherein the surfactant TD is isononanol.

4. The method according to claim 1, wherein the nucleating agent is at least one selected from the group consisting of a perfluorinated hydrocarbon and an ether having at least one perfluorinated hydrocarbyl moiety.

5. The method according to claim 1, wherein from 0.1 to 10 parts by mass of the nucleating agent is added per the 100 parts by mass of composition (ZP).

6. The method according to claim 1, wherein the nucleating agent is selected from the group consisting of perfluoropentane C.sub.5F.sub.12, perfluorohexane C.sub.6F.sub.14, perfluorocyclohexane C.sub.6F.sub.12, perfluoroheptane C.sub.7F.sub.16, perfluorooctane C.sub.8F.sub.18, a perfluorinated olefin of the empirical formulae C.sub.5F.sub.10, C.sub.6F.sub.12, C.sub.7F.sub.14, C.sub.8F.sub.16, a dimer of 1,1,2,3,3,3-hexafluoro-1-propene, methoxyheptafluoropropane, methoxynonafluorobutane and ethoxynonafluorobutane.

7. The method according to claim 1, wherein the at least one polyol is selected from the group consisting of a polyether alcohol and a polyester alcohol.

8. The method according to claim 1, wherein the at least one polyisocyanate comprises an aromatic polyfunctional isocyanate.

9. The method according to claim 1, wherein the catalyst comprises at least one selected from the group consisting of triethylamine, dimethylcyclohexylamine, tetramethylethylene diamine, tetramethylhexanediamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, triethylenediamine, dimethylpiperazine, 1,2-dimethyl imidazole, N-ethylmorpholine, tris(dimethylaminopropyl)hexahydro-1,3,5-triazine, N, N-dimethylbenzylamine, dimethylaminoethanol, dimethylaminoethoxyethanol and bis(dimethylaminoethyl) ether.

10. The method according to claim 1, wherein the catalyst comprises at least two selected from the group consisting of triethylamine, dimethylcyclohexylamine, tetramethylethylene diamine, tetramethylhexanediamine, pentamethyldiethylenetriamine, pentamethyldipropylenetriamine, triethylenediamine, dimethylpiperazine, 1,2-dimethyl imidazole, N-ethylmorpholine, tris(dimethylaminopropyl)hexahydro-1,3,5-triazine, N, N-dimethylbenzylamine, dimethylaminoethanol, dimethylaminoethoxyethanol and bis(dimethylaminoethyl) ether.

11. The method according to claim 1, wherein the polyol comprises at least one polyetherol containing: a structural unit based on propylene oxide, ethylene oxide, or both; and a structural unit based on trimethylolpropane, pentaerythritol, castor oil, glucose, sorbitol, mannitol, sucrose, a polyhydric phenol, a resol, melamine, an aniline, a toluendiamine, a methylenedianiline, or mixtures thereof.

12. The method according to claim 1, wherein the polyol comprises at least two polyethers, said polyetherols each containing: a structural unit based on propylene oxide, ethylene oxide, or both; and a structural unit based on trimethylolpropane, pentaerythritol, castor oil, glucose, sorbitol, mannitol, sucrose, a polyhydric phenol, a resol, melamine, an aniline, a toluendiamine, a methylenedianiline, or mixtures thereof.

13. The method according to claim 1, wherein the blowing agent does not include a hydrofluorocarbon.

Description

EXAMPLES

1. General Procedures

1.1 Measurement of Hydroxyl Number

(1) Hydroxyl numbers were determined to DIN53240.

1.2 Preparation of Stabilized Composition (ZS)

(2) The stabilized composition is obtained as follows:

(3) A composition (ZP) consisting of polyol mix, catalyst mixture, stabilizer and water in the amounts indicated in the examples is prepared by mixing the constituents and then initially charged. The surfactant TD is, as described in the examples, added under agitation to obtain composition Z1. Composition Z2 consisting of the nucleating agent and the blowing agent as indicated in the examples is likewise obtained by mixing the constituents. Z2 is admixed to Z1 under agitation to obtain stabilized composition (ZS). Compositions Z1, Z2 and ZS are all clear and devoid of any droplet formation or clouding as perceivable by the naked eye.

1.3. Determination of ZS Clouding

(4) As described under 1.2 in general terms, the polyol component (ZP) is initially charged to a three-neck flask equipped with mechanical stirrer and thermometer and subsequently admixed with the surfactant TD as described in the examples to obtain a composition Z1. Then, a composition Z2 consisting of the nucleating agent and the blowing agent as indicated in the examples is added. The flask is sealed gastight and the mixture is stirred at room temperature with a Vollrath stirrer at 1500 revolutions/min for about 30 min. The mixture obtained is stored gastight at room temperature and the clouding is determined visually. A solution is said to be clear when the naked eye is unable to discern any phase separation or droplet formation.

2. Production of Rigid Polyurethane Foams

2.1 Particulars Regarding Materials Used

(5) Polyol mixture consisting of: polyol 1: polyetherol based on sucrose, glycerol and propylene oxide. polyol 2: polyetherol based on vic-TDA, propylene oxide. polyol 3: polyetherol based on vic-TDA, ethylene oxide and propylene oxide. The polyol mixture used in the examples consists of the above polyols 1 to 3 being present at between 40-70% in the case of polyol 1, and between 15-50% in the case of polyol 2 and at between 5-25% in the case of polyol 3. Catalyst mixture consisting of: catalyst 1: dimethylcyclohexylamine catalyst 2: pentamethyldiethylenetriamine catalyst 3: tris(dimethylaminopropyl)hexahydro-1,3,5-triazine The catalyst mixture used in the examples consists of the above catalysts 1 to 3 being present at between 20-60% in the case of catalyst 1, and between 20-50% in the case of catalyst 2 and at between 15-40% in the case of catalyst 3. stabilizer: silicone stabilizer from Evonik, e.g., Tegostab B8467 blowing agent 1: cyclopentane (CP95) blowing agent 2: cyclopentane/isopentane 70/30 (CP70) blowing agent 3: 1,1,1,3,3-pentafluoropropane (HFC-245fa) nucleating agent: FA-188 (from 3M) surfactant TD 1: Isotridecanol N from BASF surfactant TD 2: cocoamide DEA (REWOMID® DC 212 S from Evonik Industries AG, HLB=4.1) surfactant TD 3 (V): laureth-23 (TEGO® Alkanol L 23 from Evonik Industries AG, HLB=10.3) surfactant TD 4 (V): ceteareth-29 (Emuldac AS-25 from Sasol, HLB=10.4) isocyanate: polymer MDI (Lupranat® M20 from BASF)

(6) The HLB value of the surfactants used was computed using the increment procedure of Griffin as per table 1.

2.2 Laboratory Tests

(7) The isocyanate component and stabilized composition (ZS) are temperature regulated to 20±0.5° C. The stabilized composition is obtained as described above under 1.2. The stabilized composition is initially charged to a 735 ml paper cup (PE coated), the isocyanate component is weighed in and the reaction mixture is stirred with a disk stirrer from Vollrath. The stopwatch is started as the stirring is started. Cream time, fiber time and apparent density are subsequently determined according to the following criteria:

(8) Cream time is defined as the time interval between the start of stirring and the beginning of the volume expansion by the reaction mixture through foaming.

(9) Fiber time describes the time from the start of commixing to the time in the reaction when strings can be pulled out from the foaming mass using a glass rod.

(10) Apparent Density Determination:

(11) After the foam has cured, the top of the foam is cut off. The cut is made at the edge of the test vessel perpendicularly to the direction of rise so that the location of the foam incision and the upper edge of the test vessel are in a or one plane. The beaker contents are weighed and the apparent free rise density (AD in kg/m.sup.3) is computed by the following formula:

(12) $\mathrm{AD}=\frac{\left(m_1-m_2\right)*1000}{V}$
where m.sub.1=foam weight and weight of test vessel in g m.sub.2=weight of test vessel in g V=volume of test vessel in ml

(13) The table which follows summarizes the formulation of the laboratory tests (numerical particulars in parts by weight) and the results thereof.

(14) TABLE-US-00003 Composition L1 L2 L3 L4 L5 L6 L7 L8(comp) L9(comp) polyol mixture 92.5 92.5 92.5 92.5 92.5 92.5 92.5 92.5 92.5 catalyst mixture 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 2.1 stabilizer 2.8 2.8 2.8 2.8 2.8 2.8 2.8 2.8 2.8 ZP water 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 2.6 surfactant TD 1 3 3 2 3 3 3 3 surfactant TD 2 1 surfactant TD 3 (V) 3 Z1 surfactant TD 4 (V) 3 blowing agent 1 10 15 15 15 15 blowing agent 2 10.1 15.1 blowing agent 3 19.1 28.6 ZS Z2 nucleating agent 1 1 1 1 1 1 1 1 1 sum total of parts by 114 119 119 114.1 119.1 123.1 132.6 119 119 weight of ZS ZS clouding none none none none none none none cloudy cloudy ZS foamed with Lupranat  ® M20S 151 151 151 151 151 151 151 Properties cream time [s] 8 10 10 8 10 10 10 fiber time [s] 56 64 60 55 64 60 70 apparent density 32.1 27.2 25.5 31.1 27.2 31.6 27.7 [g/l]

(15) Blowing agent proportions were adjusted so that the same molar proportions were used at all times.

2.3 Summary of Results

(16) All compositions (ZP) with various surfactants TD (resulting in Z1) are initially cloudy following admixture of the various blowing agents together with the nucleating agent (Z2). However, when TD surfactants of the present invention are used, the clouding disappears completely after a few minutes to hours. Any phase separation is no longer detectable by the naked eye. When no surfactant or a TD surfactant that is not in accordance with the present invention is used in composition Z1, all ZS's are still cloudy after weeks and phase separate.

2.4 Machine Tests

(17) The raw materials reported were used to prepare a stabilized composition (ZS) as described under 1.2. Using a Puromat® PU 30/80 IQ high-pressure machine (from Elastogran GmbH) at an output rate of 250 g/sec., ZS was mixed with the required amount of the reported isocyanate such that an isocyanate index of 110 was obtained. The reaction mixture was injected into temperature-regulated molds measuring 2000 mm×200 mm×50 mm and/or 400 mm×700 mm×90 mm and allowed to foam up therein. Overpack was 15%.

(18) The starting materials used, the preparation properties and also the mechanical properties of the foams are described in the table which follows.

(19) The table which follows summarizes the formulation of the machine tests (numerical particulars in parts by weight) and their results.

(20) Surface quality is assessed visually by determining the frequency and intensity of surface defects relative to known systems. Test 1 was chosen as reference system (0=reference; +=lower number of defects and lower intensity of surface defects as compared with reference; −=higher number of defects and higher intensity of surface defects compared with reference).

(21) TABLE-US-00004 ZS 1 2 3 (comp) 4 (comp) polyol mixture 92.55 92.55 92.7 92.7 catalyst mixture 2.1 2.1 2.05 2.05 stabilizer 2.8 2.8 2.75 2.75 water 2.55 2.55 2.5 2.5 surfactant TD 2 3.5 0 0 blowing agent 1 13.5 13.5 13.5 13.5 nucleating agent 1 1.5 1 0 sum total of 116.5 118.5 114.5 113.5 parts by weight of polyol component ZS appearance clear clear cloudy clear at RT at RT at RT at RT ZS foamed with Lupranat ® M20S 150 150 151 151 cream time [s] 5 5 4 5 fiber time [s] 44 44 38 42 free rise density 22.4 22.4 22.2 22.9 [g/l] thermal conductivity 17.9 17.8 17.9 18.6 [mW/m*K] surface quality 0 + − 0