JP6530810B2 - Antifouling suede-type artificial leather and method for producing the same - Google Patents

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 separately added. It relates to a simple and easy manufacturing method.

  The artificial leather is formed by impregnating a non-woven fabric formed by three-dimensionally entangled ultrafine fibers with a polymeric elastic body. Since artificial leather has a soft texture and a unique appearance similar to natural leather, it is widely used in various fields such as footwear, clothing, gloves, sundries, furniture, and automotive interior materials.

  The artificial leather differs in the characteristics etc. which should be provided by the use. For example, properties required of 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 an antifouling function including a water repellent function and an oil repellent function is provided so that the occurrence of contamination is suppressed even when used for 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 non-woven fabric, and fluorine linear or silicon is formed on the surface of the artificial leather. There is a way to control the external contamination by making straight chains.

  However, fluorine-based or silicon-based surfactants generally do not form chemical bonds and are free to behave in the urethane molecular structure when mixed with polyurethane as a non-active additive. This causes a phenomenon of transition to the surface of the artificial leather and causes a time-dependent change of the surface of the artificial leather.

  Korean Patent No. 0 969 839 describes a modified polyurethane to which a fluorine-containing compound is not separately added and a fluorine-bonded modified polyurethane and a method of producing a sheet-like material similar to leather using such 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) contains 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, the water repellency and the water resistance become excellent in a cross section obtained by cutting a sheet-like material similar to leather.

  However, the modified polyurethane according to the above-mentioned patent exhibits the effect as a water repellant by using a sheet-like processing solution similar to leather as an additive to be added together with the elastic polyurethane.

  Therefore, development has been advanced in order to exhibit antifouling properties by means of an impregnated elastic body, even without using antifouling additives in artificial leather.

  An object of the present invention is to provide a novel modified polyurethane-impregnated artificial leather in which an antifouling function is imparted without adding an additive having an antifouling function, in order to solve the above-mentioned problems. .

  In order to solve the above problems, the present invention provides an artificial leather in which a non-woven fabric formed by three-dimensionally intertwining ultrafine fibers is impregnated with a high-polymer elastic body and a raised is formed. The body is a fluorine-containing modified polyurethane, and the fluorine-containing modified polyurethane is a polyurethane prepolymer having an isocyanate group located at the end obtained by reacting a diol and a diisocyanate, and a fluorinated one having a hydroxy functional group at both ends A suede-type artificial leather having antifouling properties, which is a polymerization product by reaction with a carbon compound and having a weight average molecular weight (Mw) of 500,000 to 800,000.

  Further, according to the present invention, a non-woven fabric formed by three-dimensionally intertwining ultrafine fibers is impregnated with the above-mentioned polymer elastic body by immersing it in an impregnating solution containing the polymer elastic body, and a raising process is carried out In the method for producing a synthetic artificial leather, the polymer elastic body is a fluorine-containing modified polyurethane, and the fluorine-containing modified polyurethane is a urethane pretreated to have a weight average molecular weight (Mw) of 400,000 to 700,000 by reacting a diol and a diisocyanate. 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, characterized by the following.

  The artificial leather to which the antifouling function is imparted and impregnated with the fluorine-containing modified polyurethane elastic body according to the present invention exhibits a water repellent function which is superior to the antifouling property. The artificial leather of the present invention changes with time in comparison with the artificial leather manufactured by separately adding a fluorine-based surfactant, compared with the occurrence of a large change with time on the surface due to the migration of the surfactant. Can be made smaller.

  In addition, since it is not necessary to separately use and add a fluorine-based surfactant, it is possible to simplify the 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 an artificial leather. It is a grade standard of the water repellency evaluation.

  The present invention is an artificial leather in which a polymer elastic body is impregnated into a non-woven fabric formed by three-dimensionally interlacing ultrafine fibers and a raised hair is formed, wherein the polymer elastic body is a fluorine-containing modified polyurethane. It relates to an artificial leather characterized by a certain characteristic.

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

  As the diol, diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol 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 And there is no limitation to this.

  In the present invention, when the diol and the diisocyanate are reacted, the reaction ratio needs to be such that the total NCO group is in excess to the total OH group. By adjusting the proportions of the diol and the diisocyanate and reacting them in this manner, the resulting urethane prepolymer can have an isocyanate group end in the side chain.

  Here, it is desirable that the molar ratio of diol to diisocyanate is in the range of 1: 1.2 to 1: 1.4, since a fluorine-containing modified polyurethane having the weight average molecular weight range of the present invention can be produced.

  When the molar ratio is smaller than 1: 1.2, side reactions occur due to moisture in the air, active hydrogen, etc., or the isocyanates react with each other to form the property of the isocyanate which tends to form a trimer, resulting in non-activation. The increase in NCO reduces the polymerization efficiency. If the molar ratio is greater than 1: 1.4, it is undesirable because the excess of NCO groups makes the shortage of OH groups excessive and makes it difficult to increase the degree of polymerization.

  In order to ensure the mechanical properties required when the fluorine-containing modified polyurethane of the present invention is applied to artificial leather, it is necessary to easily increase the molecular weight to an appropriate level, for which purpose Urethane prepolymers can be produced first.

  If the weight average molecular weight (Mw) of the urethane prepolymer is less than 400,000, the molecular weight of the finally obtained fluorine-containing modified polyurethane decreases, and the mechanical properties such as tear strength decrease and the thermal stability is improved. Chemical physical properties such as resistance and hydrolysis resistance also decrease. If it exceeds 700,000, the gelation phenomenon may occur in the production of the fluorine-containing modified polyurethane, and the workability is lowered due to the high viscosity of the fluorine-containing modified polyurethane in the production by combining the elastic body impregnating solution. It is not desirable because the sensitivity and quality of the artificial leather may be lowered because the finally obtained fluorine-containing modified polyurethane may become hard.

  The fluorocarbon compound having a hydroxy functional group at its both ends is represented by the following chemical formula 1, and 8 to 14 fluorine groups are bonded to one chain, and a fluorine content is added to one structural group. Is 50 to 70% by mole, and is an ether diol having a hydroxy functional group 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 Chemical Formula 1 with a urethane polymer can be bonded to the side chain of the urethane polymer by bonding fluorine, which is present in the form of diatomic molecules, to other atoms or By suppressing the bond with the molecule, it is possible to impart water repellency and oil repellency. Thereby, the fluorine-containing modified polyurethane of the present invention can suppress the deposition of the external contamination source so that the contamination on the coated surface can be easily removed.

  Commercially available products for fluorinated carbon compounds having hydroxy functional groups at both ends are Solvay's Fluorolink (FLUOROLINK®).

  In the polymerization of the fluorine-containing modified polyurethane of the present invention, the fluorinated carbon compound in which the hydroxy functional group is added to the both ends only in the mole of excess isocyanate in the urethane prepolymer in which the isocyanate is bonded to both ends is By dropping into the urethane prepolymer, addition polymerization can be performed until it reaches an appropriate molecular weight.

  When the fluorinated carbon compound having a hydroxy functional group at its both ends is added once, a bond is partially formed to result in insufficient dispersion of the fluorine group, which leads to an entirely uniform stain resistance. Since it becomes difficult to express performance, it is desirable to add it slowly and drop it.

  The fluorine-containing modified polyurethane of the present invention is characterized by being polymerized by the above method and having a weight average molecular weight (Mw) of 500,000 to 800,000. When the weight-average molecular weight (Mw) is less than 500,000, the artificial leather may cause deterioration in mechanical strength such as tear strength and chemical physical properties such as thermal stability and hydrolysis resistance. 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 produced by combining the elastic body-impregnated solution, and the fluorine-containing modified finally obtained It is not desirable because the stiffness and hardness of the artificial leather can be reduced because the polyurethane becomes hard.

  The fluorine-containing modified polyurethane of the present invention preferably has a fluorine content of 5 to 20 mol%, but if it is 5 mol% or less, expression of antifouling performance is not sufficient, and if it exceeds 20 mol%, water repellency Since the performance is expressed too strongly, it is not desirable because substitution coagulation of the fluorine-containing modified polyurethane may not proceed in the process of manufacturing the artificial leather.

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

Reaction formula

  At that time, R and R ′ are each independently an alkyl group.

  Generally, in artificial leather, a non-woven fabric formed by three-dimensionally intertwining ultrafine fibers is impregnated with a polymer elastic body by immersing it in an impregnating solution containing a polymer elastic body such as polyurethane, and then solidified. After applying an elastic body to the non-woven fabric, it can be manufactured by grinding, napping 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 solution, but 100 to 200% of dimethylformamide with respect to the weight of the fluorine-containing modified polyurethane can be used. Containing modified polyurethane can be diluted and used as an impregnating solution.

  Hereinafter, the present invention will be specifically described by Examples and Comparative Examples. However, the following examples and comparative examples are for the purpose of illustrating the present invention, the present invention is not limited to the following examples, within the scope not departing from the technical concept of the present invention, Substitutions and alterations to other equivalent embodiments will be apparent to those skilled in the art to which the present invention pertains.

Production Example 1
Polymerization is carried out by the addition reaction of 0.45 moles of polytetramethylene glycol (Mw: 1500-2500), 0.47 moles of ethylene glycol, and 0.08 moles of 1,4-butanediol with 1.2 moles of 4,4'-diphenylmethane diisocyanate, and thus polymerization An 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 resulting polymer was 40% by weight.

  After the prepared prepolymer is addition-polymerized with 0.2 mol of a fluorocarbon compound (trade name: FLUOROLINK D10-H, Solvay Mw: 1,400, Mw: 1,400) having a hydroxy side chain bonded to both ends, as described above The final reaction is completed by diluting and dissolving in dimethylformamide so that the total solid content of the polymerized polymer is 30% by weight, and the final reaction is completed, the fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 800,000 Manufactured.

Production Example 2
0.45 moles of polytetramethylene glycol (Mw: 1500-2500), 0.47 moles of ethylene glycol, and 0.08 moles of 1,4-butanediol are polymerized by the addition reaction with 1.3 moles 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 is addition-polymerized with 0.3 mole of a fluorocarbon compound (trade name: FLUOROLINK D10-H, Solvay, Mw: 1,400) having hydroxy side chains bonded to both ends, Fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 700,000, which is diluted and dissolved in dimethylformamide so that the total solid content of the polymerized product is 30% by weight, and the final reaction is completed Manufactured.

[Production Example 3]
0.45 moles of polytetramethylene glycol (Mw: 1500-2500), 0.47 moles of ethylene glycol and 0.08 moles of 1,4-butanediol are polymerized by the addition reaction with 1.4 moles of 4,4'-diphenylmethane diisocyanate, An 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.

  After addition polymerization of the produced prepolymer with 0.4 mol of a fluorocarbon compound having hydroxy side chains attached to both ends, dimethyl is carried out so that the total solid content of the thus polymerized polymer will be 30% by weight The solution was diluted and dissolved in formamide to produce a fluorine-containing modified polyurethane compound having a weight average molecular weight (Mw) of 500,000, and the final reaction was finished.

Production Example 4
0.45 moles of polytetramethylene glycol (Mw: 1500-2500), 0.47 moles of ethylene glycol, and 0.08 moles of 1,4-butanediol are subjected to an addition reaction with 1.0 mole of 4,4'-diphenylmethane diisocyanate to polymerize, It was diluted and dissolved in dimethylformamide so that the total solid content of the polymerized polymer would be 70% by weight, and a reaction-terminated polyurethane compound having a weight average molecular weight (Mw) of 700,000 was produced.

Production Example 5
0.45 moles (Mw: 1500-2500) of polytetramethylene glycol, 0.47 moles of ethylene glycol and 0.08 moles of 1,4-butanediol are polymerized by addition reaction with 1.7 moles of 4,4'-diphenylmethane diisocyanate, An 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 addition polymerization of the produced prepolymer with 0.7 mol of a fluorocarbon compound having hydroxy side chains attached to both ends, the total solid content of the polymer thus polymerized is 30% by weight, It was diluted and dissolved in dimethylformamide to produce a fluorine-containing modified polyurethane compound having a weight-average molecular weight (Mw) of 450,000 that the final reaction ended.

Production Example 6
0.45 moles of polytetramethylene glycol (Mw: 1500-2500), 0.47 moles of ethylene glycol, and 0.08 moles of 1,4-butanediol are subjected to an addition reaction with 1.0 mole of 4,4'-diphenylmethane diisocyanate to polymerize, It was diluted and dissolved in dimethylformamide so that the total solid content of the polymerized polymer was 70% by weight, and a reaction-terminated polyurethane compound having a weight average molecular weight (Mw) of 700,000 was produced.

Example 1
The fluorine-containing modified polyurethane compound of Preparation Example 1 was diluted in 150% dimethylformamide with respect to the weight of the compound to prepare an impregnating solution.

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

  Thereafter, the surface of the elastic body-impregnated non-woven fabric was ground to form fiber raising on the surface, thereby producing a suede-type artificial leather.

Example 2

  A suede-type artificial leather was manufactured using the same method as in Example 1, except that the impregnating solution was prepared using the fluorine-containing modified polyurethane compound of Preparation Example 2 in Example 1.

[Example 3]
A suede-type artificial leather was manufactured using the same method as in Example 1, except that the impregnating solution was prepared using the fluorine-containing modified polyurethane compound of Preparation Example 3 in Example 1.

Comparative Example 1
A suede-type artificial leather was manufactured using the same method as in Example 1, except that the impregnating solution was prepared using the fluorine-containing modified polyurethane compound of Preparation Example 4 in Example 1.

Comparative Example 2
A suede-type artificial leather was manufactured using the same method as in Example 1, except that the impregnating solution was prepared using the fluorine-containing modified polyurethane compound of Preparation Example 5 in Example 1.

Comparative Example 3
In Example 1 above, the reaction-terminated polyurethane compound of Preparation Example 6 was mixed with a mixture of 150% by weight of dimethylformamide and 0.5% of a fluorine-based surfactant (trade name FC-4430, manufactured by 3M). A suede-type artificial leather was manufactured using the same method as Example 1, except that dilution was used to prepare the impregnating solution.

  The weight-average molecular weight (Mw) of the polymers prepared in the above Examples and Comparative Examples is determined using gel permeation chromatography (GPC) (RI-8000, Tosoh) with tetrahydrofuran (tetrahydrofuran) (flow rate 1 mL / min) Was used as the mobile phase, and the temperature of the column oven was measured at 40 ° C. by passing through a column in which TSKgel super HM-L, TSKgel super HM-M, and TSKgel super HM-N (Tosoh) were connected in series.

  Table 1 below shows the weight ratio of the polymerization raw material and the weight average molecular weight of the polymerized polymer for the above-mentioned Preparation Examples.

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

Evaluation method of stain resistance The artificial leather measurement sample is cut into a size of 5 × 15 cm and placed in a friction fastness tester (Model DL-2007), and a contaminated fabric (Test fabric, product name: IEC carbon black / mineral oil, EMPA) ) Is placed on the surface of the contaminated sample, and 10 reciprocating frictions are performed to compare the contaminated sample with the naked eye to give a contamination grade.

(Standard of pollution grade,
5: The contaminated material can not be seen at all. 4: Contaminated matter is slightly visible or hardly noticeable. 3: Some contaminants are visible and visible. 2: Contaminated material looks a bit dreadful. 1: Contaminated material looks quite awful. )

Method of evaluating the degree of water repellency Fix the artificial leather measurement sample as shown in Fig. 2 below (10 cm in diameter and then place at an angle of 45 °, then place 100 ml of water in the spray funnel located at the top) After the injection is completed and the injection is completed, the distribution map of water droplets attached to the surface of the sample is observed, and a grade is given based on the criteria of FIG. 3 below.

  From the said Table 2, the artificial leather of the Example which impregnated the fluorine-containing modified polyurethane of this invention as an elastic body exhibits antifouling performance equivalent to the artificial leather (comparative example 3) which added the fluorochemical surfactant separately. It can be confirmed that the water repellency is improved.

The artificial leather of the present invention is an artificial leather impregnated with a fluorine-containing modified polyurethane to which an anti-soiling function is added, and when manufacturing the artificial leather, it is not necessary to use a fluorine-based surfactant separately because of its anti-soiling properties. Improve productivity because it is good. Moreover, since the outstanding antifouling performance which suppresses the time-dependent change of the surface of the artificial leather resulting from use of a fluorine-type surfactant is shown, the appearance quality of an artificial leather is improved.

Claims (4)

In an artificial leather in which a non-woven fabric formed by three-dimensionally intertwining ultrafine fibers is impregnated with a polymer elastic body to form a raised hair,
The polymer elastic body is a fluorine-containing modified polyurethane,
The fluorine-containing modified polyurethane is a polymerization product obtained by the reaction of a urethane prepolymer having an isocyanate group at one end, obtained by reacting a diol and a diisocyanate, and a fluorocarbon compound having a hydroxy functional group at both ends. An anti-soiling suede type artificial leather characterized by having a weight average molecular weight (Mw) of 500,000 to 800,000.   The anti-soiling suede-type artificial leather according to claim 1, wherein the urethane prepolymer has a weight average molecular weight (Mw) of 400,000 to 700,000. The non-woven fabric formed by three-dimensionally intertwining ultrafine fibers is immersed in an impregnating solution containing a polymer elastic body to impregnate the polymer elastic body and produce an artificial leather formed by napping. 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, and the prepared prepolymer and a hydroxy functional group at both ends thereof A method for producing a suede-type artificial leather having antifouling properties, characterized in that it is produced into a polymer having a weight average molecular weight (Mw) of 500,000 to 800,000 by reacting it with a fluorinated carbon compound. 4. The anti-soiling suede type artificial leather according to claim 3 , wherein the molar ratio of the diol and the diisocyanate is reacted in the range of 1: 1.2 to 1: 1.4 when producing the urethane prepolymer. Production method.