JP2017534773A - Suede type artificial leather having antifouling property and method for producing the same - Google Patents

Abstract

TECHNICAL FIELD The present invention relates to a suede type artificial leather having antifouling properties, and an artificial leather obtained by impregnating a polymer elastic body into a nonwoven fabric formed by three-dimensionally interlacing ultrafine fibers and raising the surface. In the above, the polymer elastic body is a fluorine-containing modified polyurethane, and the fluorine-containing modified polyurethane is produced by reacting a diol with diisocyanate to produce a urethane prepolymer having a weight average molecular weight (Mw) of 400,000 to 700,000. The prepared prepolymer is reacted with a fluorocarbon compound having hydroxy functional groups at both ends to produce a weight average molecular weight (Mw) of 500,000 to 800,000. According to the present invention, by using a fluorine-containing polyurethane elastic body having an antifouling function at the time of manufacturing artificial leather, it is not necessary to separately use a fluorosurfactant for antifouling properties. It is possible to provide a suede-type artificial leather having antifouling properties that does not cause a change in the surface of the artificial leather due to the use of a surfactant.

Description

  The present invention relates to a suede type artificial leather having antifouling properties, and more specifically, as an artificial leather impregnated with a modified polyurethane having an antifouling function, an additive having an antifouling function is not added separately. The present invention relates to a simple manufacturing method.

  Artificial leather is made by impregnating a polymer elastic body into a nonwoven fabric formed by three-dimensionally interlacing ultrafine fibers. Artificial leather has a soft texture and unique appearance similar to natural leather, and is therefore widely used in various fields such as footwear, clothing, gloves, sundries, furniture, and automobile interior materials.

  The artificial leather has different characteristics to be provided depending on the application. For example, properties required for artificial leather for clothing include high durability, high sensitivity, excellent dyeability that can be dyed in various colors and densities, and high fastness.

  Among the properties required in this way, in the improvement of durability, the addition of antifouling functions including water and oil repellent functions that suppress the occurrence of contamination even when used over a long period of time, It is required for artificial leather.

  As a method for imparting an antifouling function to artificial leather, a fluorine-based or silicon-based surfactant is mixed with polyurethane, which is a polymer elastic body, and impregnated into a nonwoven fabric. There is a method of suppressing contamination from the outside by growing a straight chain.

  However, when a fluorine-based or silicon-based surfactant is generally mixed with polyurethane as an inactive additive, a chemical bond is not formed and the behavior within the urethane molecular structure is free. As a result, there is a problem in that a phenomenon of transition to the surface of the artificial leather occurs and the surface of the artificial leather changes over time.

  Korean Registered Patent No. 0969839 describes a modified polyurethane to which fluorine is bonded without separately adding a fluorine compound and a method for producing a sheet-like material similar to leather using such a modified polyurethane.

According to said patent,
(i) 3 to 12 fluorine-containing side chains having a molecular weight of 200 to 1,000 are bonded to a urethane bond-containing compound having a molecular weight of 500 to 5,000,
(ii) the fluorine content is 20 to 60% by weight in terms of fluorine atoms,
(iii) containing 6 to 36 urethane bonds per molecule;
It is described that by using a fluorine-containing side chain-modified urethane compound and this urethane compound, a sheet-like material similar to leather is cut and the water repellency and water resistance are excellent.

  However, the modified polyurethane according to the above patent exhibits an effect as a water repellent by using a sheet-like treatment liquid similar to leather as an additive added together with polyurethane as an elastic body.

  Therefore, development is being promoted so as to exhibit antifouling properties by an impregnated elastic body without using antifouling additives in artificial leather.

  In order to solve the above problems, an object of the present invention is to provide an artificial leather impregnated with a new modified polyurethane, which is provided with an antifouling function without adding an additive having an antifouling function. .

  In order to solve the above problems, the present invention provides an artificial leather obtained by impregnating a non-woven fabric formed by three-dimensionally entanglement of ultrafine fibers with a polymer elastic body to form raised hair. The body is a fluorine-containing modified polyurethane, and the fluorine-containing modified polyurethane is obtained by reacting a diol with a diisocyanate, a urethane prepolymer having an isocyanate group located at the terminal, and a fluorinated group having hydroxy functional groups at both terminals. Provided is a suede type artificial leather having antifouling property, which is a polymerization product obtained by a reaction with a carbon compound and having a weight average molecular weight (Mw) of 500,000 to 800,000.

  Further, the present invention is to impregnate the polymer elastic body by raising the nonwoven fabric formed by three-dimensionally entanglement of ultrafine fibers in an impregnating liquid containing the polymer elastic body, and raising the surface. In the method for producing artificial leather, the polymer elastic body is a fluorine-containing modified polyurethane, and the fluorine-containing modified polyurethane reacts with a diol and a diisocyanate to give a urethane prepolymer having a weight average molecular weight (Mw) of 400,000 to 700,000. A polymer is produced, and the produced prepolymer is reacted with a fluorocarbon compound having hydroxy functional groups at both ends to produce a polymer having a weight average molecular weight (Mw) of 500,000 to 800,000. The present invention provides a method for producing a suede type artificial leather having antifouling properties.

  The artificial leather impregnated with a fluorine-containing modified polyurethane elastic body imparted with an antifouling function according to the present invention exhibits an excellent water repellent function in addition to the antifouling property. The artificial leather of the present invention is a time-dependent change in the surface of the artificial leather produced by adding a fluorosurfactant separately, as compared with the fact that a change with time occurs on the surface due to the migration of the surfactant. Can be reduced.

  Moreover, since it is not necessary to add and use a fluorine-type surfactant separately, it is possible to simplify a manufacturing method.

1 is a polymerization reaction formula of a fluorine-containing modified polyurethane according to one embodiment of the present invention. It is drawing of the water repellency evaluation test equipment of artificial leather. It is a grade standard for the evaluation of water repellency.

  The present invention relates to an artificial leather formed by impregnating a non-woven fabric formed by three-dimensionally entanglement of ultrafine fibers with a polymer elastic body to form raised hair, and the polymer elastic body is a fluorine-containing modified polyurethane. It relates to an artificial leather characterized by being.

  The fluorine-containing modified polyurethane is a urethane prepolymer having an isocyanate group located at the end obtained by addition reaction of diol and diisocyanate and having a weight average molecular weight (Mw) of 400,000 to 700,000, and a hydroxy functional group at both ends. A fluorine-containing modified polyurethane having a Mw of 500,000 to 800,000, which is a polymerization product obtained by an addition reaction with a fluorinated carbon compound.

  Examples of the diol include diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, either alone or in combination. Can be used.

  Examples of the diisocyanate include 1,4-tetramethylene diisocyanate, 1,6 hexamethylene diisocyanate, 1,12-dodecamethylene diisocyanate, cyclohexane-1,3- to 1,4-diisocyanate, 1-isocyanate-3-isocyanate methyl- 3,5,5-trimethylcyclohexane (isophorone diisocyanate), bis- (4-isocyanatocyclohexyl) methane (hydrogenated MDI), 2- to 4-isocyanatocyclohexyl-2-isocyanatocyclohexylmethane, 1,3- to 1,4 -Tetramethylxylene diisocyanate, 2,4- to 2,6-toluene diisocyanate, 2,2-2,4- to 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, xylene diisocyanate, diphenyl-4,4 -There is a diisocyanate etc., but it is not limited to this.

  In the present invention, when the diol and the diisocyanate are reacted, the ratio of the reaction needs to be an amount ratio in which all the NCO groups are in excess of all the OH groups. Thus, the urethane prepolymer obtained by adjusting and reacting the ratio of diol and diisocyanate can have the terminal of an isocyanate group in a side chain.

  Here, the molar ratio of the diol and the diisocyanate is preferably in the range of 1: 1.2 to 1: 1.4 because the fluorine-containing modified polyurethane having the weight average molecular weight range of the present invention can be produced.

  When the molar ratio is less than 1: 1.2, side effects occur due to moisture in the air, active hydrogen, etc., and the properties of isocyanates that try to form trimers by reacting with isocyanates are expressed and are inactive. The polymerization efficiency decreases due to the increase in NCO. If the molar ratio is greater than 1: 1.4, an excessive amount of NCO groups will cause a shortage of OH groups, making it difficult to increase the degree of polymerization.

  In order to secure the mechanical properties required when the fluorine-containing modified polyurethane of the present invention is applied to artificial leather, it is necessary to easily raise the polymerization molecular weight to an appropriate level. The urethane prepolymer can be manufactured first.

  In the urethane prepolymer, if the weight average molecular weight (Mw) is less than 400,000, the molecular weight of the finally obtained fluorine-containing modified polyurethane is lowered, mechanical properties such as tear strength are lowered, and thermal stability is reduced. Chemical properties such as resistance and hydrolysis resistance also deteriorate. If it exceeds 700,000, gelation may occur in the production of fluorine-containing modified polyurethane, and the workability is reduced because the viscosity of fluorine-containing modified polyurethane is high when combined with the elastic material impregnation liquid. In addition, since the finally obtained fluorine-containing modified polyurethane can be hardened, the sensitivity and quality of the artificial leather can be lowered, which is not desirable.

  The fluorocarbon compound having a hydroxy functional group at both ends is represented by the following chemical formula 1, wherein 8 to 14 fluorine groups are bonded to one chain, and fluorine content is contained in one structural group. Is an ether diol having 50 to 70 mol% and having hydroxy functional groups at both ends.

[Chemical formula 1]
HO-CH ₂ -CF ₂ -O- (CF ₂ CF ₂ O) m- (CF ₂ O) n-CF ₂ -CH ₂ -OH

  The fluorine-containing modified polyurethane obtained by reacting the ether diol of the chemical formula 1 with a urethane polymer is bonded to the side chain of the urethane polymer with fluorine existing as a diatomic molecule in the elemental state, thereby allowing other atoms or By suppressing the bond with the molecule, water repellency and oil repellency can be imparted. Thereby, the fluorine-containing modified polyurethane of the present invention can suppress the deposition of the external contamination source, and can easily remove the contaminant on the coated surface.

  A commercial product of the fluorinated carbon compound having hydroxy functional groups at both ends is Solvay's FLUOROLINK (registered trademark).

  Polymerization of the fluorine-containing modified polyurethane of the present invention is carried out by adding a fluorocarbon compound having hydroxy functional groups attached to both ends of the urethane prepolymer in which isocyanate is bonded to both ends, in excess of the mole of isocyanate. By adding dropwise to the urethane prepolymer, addition polymerization can be carried out until an appropriate molecular weight is reached.

  When the above-mentioned fluorinated carbon compounds having hydroxy functional groups attached to both ends are added all at once, bonds are partially formed and the dispersion of the fluorine groups becomes insufficient. Since it becomes difficult to develop the performance, it is desirable to slowly drop the solution.

  The fluorine-containing modified polyurethane of the present invention is polymerized by the above-described method, and has a weight average molecular weight (Mw) of 500,000 to 800,000. If the weight average molecular weight (Mw) is less than 500,000, the artificial leather can cause mechanical strength such as tear strength and chemical properties such as thermal stability and hydrolysis resistance to be lowered. If the weight average molecular weight (Mw) exceeds 800,000, the workability may be reduced due to the high viscosity of the fluorine-containing modified polyurethane when the elastic body impregnating liquid is combined, and the fluorine-containing modified finally obtained Since polyurethane becomes stiff, sensitivity and quality in artificial leather can be lowered, which is not desirable.

  In the fluorine-containing modified polyurethane of the present invention, the fluorine component is preferably 5 to 20 mol%, but if it is 5 mol% or less, the antifouling performance is not sufficiently expressed, and if it exceeds 20 mol%, the water repellent property Since the performance is expressed so strongly, the substitutional coagulation of the fluorine-containing modified polyurethane may not proceed in the artificial leather manufacturing process, which is not desirable.

  An example of the synthesis reaction formula of the fluorine-containing modified polyurethane described above can be shown by the following reaction formula.

[Reaction formula]

  In this case, R and R ′ are each independently an alkyl group.

  In general, artificial leather is made by impregnating and coagulating a polymer elastic body by immersing a nonwoven fabric formed by three-dimensionally entanglement of ultrafine fibers in an impregnation liquid containing a polymer elastic body such as polyurethane. After an elastic body is imparted to the nonwoven fabric, it can be produced by grinding, raising, and dyeing.

  In the present invention, the fluorine-containing modified polyurethane of the present invention can be used as the polymer elastic body of the impregnating liquid, but 100% to 200% of dimethylformamide with respect to the weight of the fluorine-containing modified polyurethane is replaced with fluorine. The contained modified polyurethane can be diluted and used as an impregnation liquid.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. However, the following examples and comparative examples are for the purpose of illustrating the present invention, and the present invention is not limited to the following examples, and within the scope of the technical idea of the present invention, It will be apparent to those skilled in the art to which the present invention pertains that substitutions and modifications can be made to other equivalent embodiments.

[Production Example 1]
Polytetramethylene glycol 0.45 mol (Mw: 1500-2500), ethylene glycol 0.47 mol, and 1,4-butanediol 0.08 mol were polymerized by addition reaction with 4,4'-diphenylmethane diisocyanate 1.2 mol, thus polymerizing The NCO-terminated polyurethane prepolymer having a weight average molecular weight (Mw) of 700,000 was prepared by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized product was 40% by weight.

  The resulting prepolymer was subjected to addition polymerization with 0.2 mol of a fluorocarbon compound (trade name FLUOROLINK D10-H, Solvay, Mw: 1,400) having hydroxy side chains bonded to both ends, and then Fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 800,000, diluted and dissolved in dimethylformamide so that the total solid content of the polymerized polymer is 30% by weight. Manufactured.

[Production Example 2]
Polytetramethylene glycol 0.45 mol (Mw: 1500-2500), ethylene glycol 0.47 mol, and 1,4-butanediol 0.08 mol were polymerized by addition reaction with 1.3 mol of 4,4′-diphenylmethane diisocyanate. An NCO-terminated polyurethane prepolymer having a weight average molecular weight (Mw) of 600,000 was prepared by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized polymer was 40% by weight.

  The prepared prepolymer was subjected to addition polymerization with 0.3 mol of a fluorocarbon compound (trade name: FLUOROLINK D10-H, Solvay, Mw: 1,400) having hydroxy group side chains bonded to both ends, The fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 700,000, which was diluted and dissolved in dimethylformamide so that the total solid content of the polymerized polymer was 30% by weight. Manufactured.

[Production Example 3]
Polytetramethylene glycol 0.45 mol (Mw: 1500-2500), ethylene glycol 0.47 mol, and 1,4-butanediol 0.08 mol were polymerized by addition reaction with 1.4 mol of 4,4′-diphenylmethane diisocyanate. The NCO-terminated polyurethane prepolymer having a weight average molecular weight (Mw) of 400,000 was prepared by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized polymer was 40% by weight.

  The prepared prepolymer is subjected to addition polymerization with 0.4 mol of a fluorocarbon compound having hydroxy group side chains bonded to both ends, and dimethyl so that the total solid content of the polymerized polymer is 30% by weight. A fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 500,000 was prepared by diluting and dissolving in formamide.

[Production Example 4]
Polytetramethylene glycol 0.45 mol (Mw: 1500-2500), ethylene glycol 0.47 mol, and 1,4-butanediol 0.08 mol were polymerized by addition reaction with 1.0 mol of 4,4′-diphenylmethane diisocyanate, thus A final reaction type polyurethane compound having a weight average molecular weight (Mw) of 700,000 was prepared by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized polymer was 70% by weight.

[Production Example 5]
Polytetramethylene glycol 0.45 mol (Mw: 1500-2500), ethylene glycol 0.47 mol, and 1,4-butanediol 0.08 mol were polymerized by addition reaction with 1.7 mol of 4,4′-diphenylmethane diisocyanate. The NCO-terminated polyurethane prepolymer having a weight average molecular weight (Mw) of 350,000 was prepared by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized polymer was 40% by weight.

  After the prepolymer thus produced is subjected to addition polymerization with 0.7 mol of a fluorocarbon compound having hydroxy group side chains bonded to both ends, so that the total solid content of the polymerized in this way is 30% by weight, A fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 450,000, in which the final reaction was completed, was prepared by diluting and dissolving in dimethylformamide.

[Production Example 6]
Polytetramethylene glycol 0.45 mol (Mw: 1500-2500), ethylene glycol 0.47 mol, and 1,4-butanediol 0.08 mol were polymerized by addition reaction with 1.0 mol of 4,4′-diphenylmethane diisocyanate, thus A final reaction type polyurethane compound having a weight average molecular weight (Mw) of 700,000 was prepared by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized polymer was 70% by weight.

[Example 1]
The fluorine-containing modified polyurethane compound of Production Example 1 was diluted with 150% of dimethylformamide based on the weight of the compound to prepare an impregnation solution.

  Polyester fiber (0.3 denier, fiber length 51 mm) is taken out by immersing the self-entangled non-woven fabric in the impregnating solution, coagulated with an aqueous solution diluted with 20% by weight of dimethylformamide, and elastic modified fluorine-containing polyurethane compound An elastic body-impregnated nonwoven fabric in which the body was impregnated and a fine porous layer was formed in the fiber structure was produced.

  Then, the surface of the said elastic body impregnation nonwoven fabric was ground, and the suede type artificial leather was manufactured by forming a fiber raising hair on the surface.

[Example 2]

  A suede type artificial leather was produced in the same manner as in Example 1 except that the impregnating solution was produced using the fluorine-containing modified polyurethane compound of Production Example 2.

[Example 3]
A suede type artificial leather was produced in the same manner as in Example 1 except that the impregnating solution was produced using the fluorine-containing modified polyurethane compound of Production Example 3.

[Comparative Example 1]
A suede type artificial leather was produced in the same manner as in Example 1 except that the impregnating solution was produced using the fluorine-containing modified polyurethane compound of Production Example 4.

[Comparative Example 2]
A suede type artificial leather was produced in the same manner as in Example 1 except that the impregnating solution was produced using the fluorine-containing modified polyurethane compound of Production Example 5.

[Comparative Example 3]
In Example 1, the reaction-terminated polyurethane compound of Production Example 6 was mixed into a mixture of 150% dimethylformamide by weight and 0.5% fluorosurfactant (trade name FC-4430, 3M Company). A suede type artificial leather was produced using the same method as in Example 1 except that the impregnation solution was prepared by dilution.

  The weight average molecular weight (Mw) of the polymers produced in the examples and comparative examples is tetrahydrofuran (flow rate 1 mL / min) using gel permeation chromatography (GPC) (RI-8000, Tosoh). Was passed through a column in which TSKgel super HM-L, TSKgel super HM-M, and TSKgel super HM-N (Tosoh) were connected in series, and the temperature in the column oven was 40 ° C.

  Table 1 below shows the composition ratio of the polymerization raw materials and the weight-average molecular weight of the polymerized product with respect to the above production examples.

  The properties of the artificial leathers produced in the examples and comparative examples were evaluated according to the following stain resistance evaluation method, and the results are shown in Table 2 below.

Evaluation method of contamination resistance Artificial leather measurement sample was cut out to a size of 5x15cm and placed on a friction fastness tester (model DL-2007), and the contamination fabric (Test fabric, product name: IEC carbon black / mineral oil, EMPA) ) Is placed on the surface of the contaminated sample and 10 reciprocating rubs are performed to compare the contaminated sample with the naked eye and give a contamination rating.

(Contamination grade criteria,
5: Contaminated materials are not visible at all. 4: Contaminated materials are slightly visible or hardly noticeable. 3: Some contamination is visible. 2: The contaminated material looks somewhat severe. 1: The contaminated material looks quite heavy. )

Evaluation Method of Water Repellency Artificial leather measurement sample is fixed as shown in Fig. 2 below (10cm in diameter and then tilted at an angle of 45 °. Then, 100ml of water is placed in the spray funnel located at the top. After spraying, observe the distribution map of water droplets on the surface of the sample, and give a grade according to the criteria shown in Fig. 3 below.

  From Table 2 above, the artificial leather of the example impregnated with the fluorine-containing modified polyurethane of the present invention as an elastic body exhibits the same antifouling performance as the artificial leather (Comparative Example 3) to which a fluorosurfactant is separately added. In addition, it can be confirmed that the improved water repellency is exhibited.

The artificial leather of the present invention is an artificial leather impregnated with a fluorine-containing modified polyurethane imparted with an antifouling function, and a fluorine-based surfactant is not separately used for the antifouling property when the artificial leather is manufactured. You can improve productivity. Moreover, since the antifouling property which suppresses the time-dependent change of the surface of the artificial leather resulting from use of a fluorine-type surfactant is shown, the external appearance quality of artificial leather is improved.

Claims (6)

In the artificial leather formed by impregnating a polymer elastic body into a non-woven fabric formed by entanglement of ultrafine fibers in three dimensions,
The polymer elastic body is a fluorine-containing modified polyurethane,
The fluorine-containing modified polyurethane is a polymerization product obtained by reacting a urethane prepolymer having an isocyanate group located at a terminal obtained by reacting a diol with a diisocyanate and a fluorocarbon compound having a hydroxy functional group at both terminals. A suede type artificial leather having antifouling property, wherein the weight average molecular weight (Mw) is 500,000 to 800,000.   The suede-type artificial leather having antifouling property according to claim 1, wherein the urethane prepolymer has a weight average molecular weight (Mw) of 400,000 to 700,000.   The fluorocarbon compound having a hydroxy functional group at both ends has 8 to 14 fluorine groups bonded to one chain, and the fluorine content in one structural group is 50 to 70 mol%. The suede type artificial leather having antifouling properties according to claim 1, wherein the diol is an ether diol having hydroxy functional groups at both ends. Manufacture of artificial leather made by impregnating the above-mentioned polymer elastic body by immersing a non-woven fabric formed by three-dimensionally entanglement of ultrafine fibers in an impregnating solution containing the polymer elastic body In the method
The polymer elastic body is a fluorine-containing modified polyurethane,
The fluorine-containing modified polyurethane is produced by reacting a diol and a diisocyanate to produce a urethane prepolymer having a weight average molecular weight (Mw) of 400,000 to 700,000. The prepolymer thus produced and hydroxy functional groups are imparted to both ends. A method for producing a suede-type artificial leather having antifouling property, wherein the polymer is produced by reacting with a fluorocarbon compound and having a weight average molecular weight (Mw) of 500,000 to 800,000.   The suede type artificial leather having antifouling property according to claim 4, wherein the urethane prepolymer is reacted in a molar ratio of the diol and diisocyanate in the range of 1: 1.2 to 1: 1.4. Production method. The fluorocarbon compound having hydroxy functional groups at both ends has 8 to 14 fluorine groups bonded to one chain, and the fluorine content of one structural group is 50 to 70 mol%. The method for producing a suede-type artificial leather having antifouling properties according to claim 4, wherein the diol is an ether diol having hydroxy functional groups at both ends.