Adaptive vapor barrier

Abstract

The present invention relates to the use, as water vapour barrier, of a film, of a textile or of a layer of material P, said material P comprising, or even consisting of, at least one copolymer A which is a polyamide of PAXY/XAIS M.sup.n+.sub.1/n type or of PAZ/XAISM.sup.n+.sub.1/n type. It also relates to a construction element comprising a film, a textile or a layer of said material P and a construction material.

Claims

1. A method for manufacturing an ambient humidity adaptive water vapor barrier, the method comprising preparing a film, a textile or a layer of material P, said material P comprising at least one copolymer A which is a polyamide represented by PAXY/XAIS M.sup.n+.sub.1/n or represented by PAZ/XAISM.sup.n+.sub.1/n, in which X, Y and Z represent, independently of one another, integers ranging from 3 to 36, M.sup.n+.sub.1/n, with n representing the number of charges of M, and M representing Li.sup.+, Na.sup.+, K.sup.+, Ag.sup.+, Cu.sup.+, Cu.sup.2+Zn.sup.2+, Mn.sup.2+, Mg.sup.2+, Fe.sup.2+, Fe.sup.3+, Al.sup.3+, NH.sup.4+, and/or phosphonium, and AIS represents a residue derived from 5-sulfoisophthalic acid; and combining the film, textile or layer of material P with a solid support selected from the group consisting of reinforced or non-reinforced concrete, bricks, metal, cellular glass, metal sheets, and glass; wherein the film, textile or layer of material P, has a water vapor permeability: less than or equal to 0.25 g.Math.mm/m.sup.2.Math.J, at 23 C. and at an average humidity level of 25%, and/or greater than or equal to 3 g.Math.mm/m.sup.2.Math.J, at 23 C. and at an average humidity level of 75%.

2. The method according to claim 1, wherein the film, textile or layer of material P, has a (water vapor permeability at 23 C. and at an average humidity level of 75%)/(water vapor permeability at 23 C. and at an average humidity level of 25%) ratio greater than or equal to 15.

3. The method according to claim 2, wherein the film, textile or layer of material P, has a (water vapor permeability at 23 C. and at an average humidity level of 75%)/(water vapor permeability at 23 C. and at an average humidity level of 25%) ratio greater than or equal to 35.

4. The method according to claim 1, wherein the copolymer A is obtained by polymerization: of a diamine selected from the group consisting of 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane or hexamethylenediamine (HMD), 2-methylpentamethylenediamine, 2-methylhexamethylenediamine, 3-methylhexamethylenediamine, 2,5-dimethylhexamethylenediamine, 2,2-dimethylpentamethylenediamine, 1,8-diaminooctane, methyl-1,8-diaminooctane, 1,9-diaminononane, 5-methylnonanediamine, 1,10-diaminodecane or decamethylenediamine, 1,12-diaminododecane, or dodecamethylenediamine, and N-(6-aminohexyl)-N-methyl-1,6-hexanediamine, of a diacid selected from the group consisting of oxalic acid, succinic acid (HOOC(CH.sub.2).sub.2COOH), glutaric acid (HOOC(CH.sub.2).sub.3COOH), 2-methylglutaric acid (HOOCCH(CH.sub.3)(CH.sub.2).sub.2COOH), 2,2-dimethylglutaric acid (HOOCC(CH.sub.3).sub.2(CH.sub.2).sub.2COOH), adipic acid (HOOC(CH.sub.2).sub.4COOH), 2,4,4-trimethyladipic acid (HOOCCH(CH.sub.3)CH.sub.2C(CH.sub.3).sub.2CH.sub.2COOH), pimelic acid (HOOC(CH.sub.2).sub.5COOH), suberic acid (HOOC(CH.sub.2).sub.6COOH), azelaic acid (HOOC(CH.sub.2).sub.7COOH), sebacic acid (HOOC(CH.sub.2).sub.8COOH), undecanedioic acid (HOOC(CH.sub.2).sub.9COOH), dodecanedioic acid (HOOC(CH.sub.2).sub.10COOH), terephthalic acid and isophthalic acid, and of 5-sulfoisophthalic acid of lithium, sodium, potassium, silver, copper I or II, zinc, manganese, magnesium, iron II or III, ammonium or phosphonium.

5. The method according to claim 1, wherein the copolymer A is obtained by polymerization: of a diamine selected from the group consisting of 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane or hexamethylenediamine (HMD), 2-methylpentamethylenediamine, 2-methylhexamethylenediamine, 3-methylhexamethylenediamine, 2,5-dimethylhexamethylenediamine, 2,2-dimethylpentamethylenediamine, 1,8-diaminooctane, methyl-1,8-diaminooctane, 1,9-diaminononane, 5-methylnonanediamine, 1,10-diaminodecane or decamethylenediamine, 1,12-diaminododecane, or dodecamethylenediamine, and N-(6-aminohexyl)-N-methyl-1,6-hexanediamine, of an amino acid or a lactam selected from the group consisting of caprolactam, 6-aminohexanoic acid, 10-aminodecanoic acid, 11-aminoundecanoic acid and 12-dodecanolactam, and of 5-sulfoisophthalic acid of lithium, sodium, potassium, silver, copper I or II, zinc, manganese, magnesium, iron II or III, ammonium or phosphonium.

6. The method according to claim 1, wherein the copolymer A comprises PA66/6AISLi and/or PA66/6AISNa.

7. The method according to claim 1, wherein the copolymer A comprises a content of aromatic repeat unit ranging from 0.1 to 60 mol %, relative to the total number of repeat units in the polyamide.

8. The method according to claim 1, wherein the material P further comprises at least one other polymer, in this case the polyamide constitutes a continuous phase.

9. The method according to claim 1, wherein the material P comprises at least one impact modifier, i.e. a compound capable of modifying the impact strength of a polyamide composition.

10. The method according to claim 1, wherein the material P further comprises pigments, mineral or organic fillers, matting agents, heat-, light- and/or UV-stabilizers, lubricants, plasticizers or flame retardants.

11. The method according to claim 1, wherein the film of material P has a thickness ranging from 10 to 500 m, the layer of material P has a thickness ranging from 1 to 500 m or the textile of material P has a thickness ranging from 50 m to 2 mm.

12. The method according to claim 1, wherein X, Y and Z represent, independently of one another, integers ranging from 4 to 18.

13. The method according to claim 1, wherein X, Y and Z represent, independently of one another, integers ranging from 4 to 12.

14. The method according to claim 1, wherein M represents Li.sup.+ and/or Na.sup.+.

15. A construction element comprising at least one film, one textile or one layer of material P and at least one construction material suitable for producing wall or roof structures selected from the group consisting of reinforced or non-reinforced concrete, bricks, metal, cellular glass, metal sheets, and glass; wherein said material P comprises at least one copolymer A which is a polyamide represented by PAXY/XAIS M.sup.n+.sub.1/n or represented by PAZ/XAISM.sup.n+.sub.1/n, in which X, Y and Z represent, independently of one another, integers ranging from 3 to 36, M.sup.n+.sub.1/n, with n representing the number of charges of M, and M representing Li.sup.+, Na.sup.+, K.sup.+, Ag.sup.+, Cu.sup.+, Cu.sup.2+Zn.sup.2+, Mn.sup.2+, Mg.sup.2, Fe.sup.2+, Fe.sup.3+, Al.sup.3+, NH.sup.4+, and/or phosphonium, and AIS represents a residue derived from 5-sulfoisophthalic acid.

Description

EXPERIMENTAL SECTION

(1) Characterizations

(2) Physicochemical Property Analysis

(3) The acid end group (CEG) and amine end group (AEG) contents are assayed by potentiometry, expressed in meq/kg.

(4) The number-average molar mass Mn is determined by the formula Mn=2.10.sup.6/(AEG+CEG), and expressed in g/mol.

(5) Thermal Property Analysis:

(6) The melting points (Mp), crystallization temperatures on cooling (Tc) and glass transition temperatures (Tg) of the extruded films obtained are determined by Differential Scanning calorimetry (DSC), using a TA Instruments Q2000 device, at a rate of 10 C./min. The degree of crystallinity is obtained by calculating Xc=Hf/Hf, where Hf is the enthalpy of fusion of the polyamide sample tested and Hf is the enthalpy of fusion of a pure polyamide crystal (Hf (PA66)=188 J/g). The values are given for dry products.

(7) Water Vapor Permeability Analysis:

(8) The extruded films are conditioned at 23 C. at relative humidity of 50% (RH50) until their water uptake reaches equilibrium. The water vapor permeability is then evaluated at various relative humidities.

(9) Average Relative Humidity of 75% (RH.sub.75):

(10) Polymer films, the thickness of which has been accurately measured (approximately 300 m), are attached in leaktight-sealed aluminum permeation crucibles containing liquid water, with the internal face of the polymer film in contact with water vapor, and a layer of air of approximately 1 cm being present between the liquid water and the polymer. The cells are then placed in a laboratory in which the environment is regulated in terms of temperature (23 C.) and in terms of relative humidity (50%).

(11) In this configuration, the polymer film is exposed on the cell side to a relative humidity of 100% and on the external environment side to a relative humidity of 50%, it being possible for the average relative humidity in the membrane to be considered as equal to ((50+100)/2)=75%.

(12) The weight of the assembly (crucible+film+water) is measured over time. After a certain time called the induction time, a weight loss corresponding to the water vapor permeation through the polymer film from the inside of the crucible to the outside is measured, and a permeability value representing this weight loss related to time, at the film surface and multiplied by the film thickness can be established (Permeability P expressed in g.Math.mm/m.sup.2.Math.J).

(13) Average Relative Humidity of 25% (RH.sub.25):

(14) Polymer films, the thickness of which has been accurately measured (approximately 300 m), are attached in leaktight-sealed aluminum permeation crucibles containing silica gel dried for 48 h at 110 C. The internal face of the polymer film is in contact with dry air, a layer of air of approximately 1 cm being present between the silica gel and the polymer.

(15) The cells are placed in a laboratory in which the environment is regulated in terms of temperature (23 C.) and in terms of relative humidity (50%). In this configuration, the polymer film is exposed on the cell side to a relative humidity of 0% and on the external environment side to a relative humidity of 50%, it being possible for the average relative humidity in the membrane to be considered as equal to ((0+50)/2)=25%.

(16) The weight of the assembly (crucible+film+water) is measured over time. After a certain time called the induction time, a weight gain corresponding to the water vapor permeation through the polymer film from the outside of the crucible to the inside is measured, and a permeability value representing this weight gain related to time, at the film surface and multiplied by the film thickness can be established (Permeability P to water vapor, expressed in g.Math.mm/m.sup.2.Math.J).

Example 1 (Comparative): Films of Non-Modified PA66

(17) 92.6 kg (353 mol) of salt N (1:1 hexamethylene diamine and adipic acid salt), 84 kg of demineralized water and 6.4 g of antifoam Silcolapse 5020 are placed in a polymerization reactor. The polyamide 66 is made according to a standard polyamide 66 polymerization process, with 30 minutes finishing. The polymer obtained is poured into rods, cooled, and shaped into granules by cutting the rods.

(18) The polymer obtained has the following characteristics: CEG=70.2 meq/kg, AEG=51.5 meq/kg, Mn=16 430 g/mol.

(19) The granules of PA66 are then placed in a twin-screw co-rotating Leistritz extruder (D=34, L/D=35), with screw rate 255 rpm and temperature 280 C. An OCS wrapping machine with a flat sheet die (width 300, gap 500 m) delivers films 300 m thick, the film coming out of the die being stretched at a rate of 2 m/minute, the cooling roll temperature being 135 C.

(20) The films obtained have the following thermal characteristics: PA 66: Tg=62 C., Mp=262 C., Tc=229 C., Hf=68 J/g i.e. Xc=36.1%.

(21) The water vapor-barrier properties at 23 C. are then determined. At RH.sub.25, the permeability P.sub.RH25 is 0.230.01 g.Math.mm/m.sup.2.Math.J At RH.sub.75, the permeability P.sub.RH75 is 2.70.5 g.Math.mm/m.sup.2.Math.J

Example 2: Polyamide 66 Sulfonate PA66/6AISLi 95/5 Mol/Mol

(22) 85.9 kg (327.5 mol) of salt N (1:1 salt of hexamethylene diamine and adipic acid), 4,657 g of lithium 5-sulfoisophthalic acid salt at 93.33% (AISLi) (17.24 mol), 6,435 g of a solution of hexamethylene diamine (HMD) in solution in water at 32.47% by weight (17.98 mol) and 81.2 kg of demineralized water and 6.4 g of Silcolapse 5020 antifoam are placed in a polymerization reactor. The polyamide 66 sulfonate is made according to a standard polyamide 66 polymerization process, with 30 minutes finishing at atmospheric pressure. The polymer obtained is poured into rods, cooled, and shaped into granules by cutting the rods.

(23) The polymer obtained has the following characteristics: CEG=102.6 meq/kg, AEG=94.3 meq/kg, Mn 32 10 160 g/mol.

(24) The granules of PA66 sulfonate PA 66/6AISLi 95/5 mol/mol are then placed in a twin-screw co-rotating Leistritz extruder (D=34, L/D=35), with screw rate 255 rpm and temperature 280 C. An OCS wrapping machine with a flat sheet die (width 300, gap 500 m) delivers films 300 m thick, the film coming out of the die being stretched at a rate of 2 m/minute, the cooling roll temperature being 135 C.

(25) The film obtained has the following thermal characteristics: PA66/6AISLi (95/5): Tg=88 C., Mp=253 C., Tc=220 C., Hf=66 J/g i.e. Xc=35%.

(26) The water vapor-barrier properties at 23 C. are then determined. At RH.sub.25, the permeability P.sub.RH25 is 0.140.01 g.Math.mm/m.sup.2.Math.J, i.e. a 40% reduction in permeability in comparison with the non-modified PA66 film. At RH.sub.75, the permeability P.sub.RH75 is 5.30.3 g.Math.mm/m.sup.2.Math.J, i.e. a 100% increase in permeability in comparison with the non-modified PA66 film.

(27) The PA66/6AISLi 95/5 mol/mol film thus exhibits a decrease in permeability in winter-type conditions (at low RH, 40% is achieved) and an increase in permeability in summer-type conditions (at high RH, +100% is achieved) compared with a non-modified PA66 film. A factor of 38 is obtained between the permeability at low RH and the permeability at high RH.

Example 3: Polyamide 66 Sulfonate PA66/6AISNa 95/5 Mol/Mol

(28) The polyamides of example 3 is produced according to the same protocol as the one presented in example 2, except that the sodium salt of 5-sulfoisophthalic acid at 95% (AISNa) is used.

(29) The polymer obtained has the following characteristics: CEG=112.7 meq/kg, AEG=99.0 meq/kg, Mn=9450 g/mol.

(30) The granules and then the film of this polyamide are obtained in the same way as described in example 2.

(31) The film obtained has the following thermal characteristics: PA66/6AISNa (95/5): Tg=87 C., Mp=253 C., Tc=221 C., Hf=64 J/g i.e. Xc=34%.

(32) The water vapor-barrier properties at 23 C. are then determined. At RH.sub.25, the permeability P.sub.RH25 is 0.210.02 g.Math.mm/m.sup.2.Math.J, i.e. a 10% reduction in permeability in comparison with the non-modified PA66 film. At RH.sub.75, the permeability P.sub.RH75 is 11.790.2 g.Math.mm/m.sup.2.Math.J, i.e. a more than 300% increase in permeability in comparison with the non-modified PA66 film.

(33) The PA66/6AISNa 95/5 mol/mol film thus exhibits a decrease in permeability in winter-type conditions (at low RH, 10% is achieved) and a very strong increase in permeability in summer-type conditions (at high RH, +300% is achieved) compared with a non-modified PA66 film. A factor of 56 is obtained between the permeability at low RH and the permeability at high RH.