Polyurethane resin composition and method for producing same

Abstract

The present invention provides a polyurethane resin composition for hot melt adhesives that uses polytrimethylene ether glycol from which cyclic oligomers have been removed, and a method for producing the same.

Description

[Technical Field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0072269, filed June 14, 2022, and Korean Patent Application No. 10-2023-0073024, filed June 7, 2023, and all contents disclosed in the documents of said Korean patent applications are incorporated herein by reference.

[0002] The present invention relates to a polyurethane resin composition for hot melt adhesives and a method for producing the same. [Background technology]

[0003] Generally, products such as shoes, bags, and wallets have various parts, decorations, or fabrics for interlocking attached to a woven or synthetic resin body by sewing or gluing. However, when multiple sewing steps are performed, complex stitching lines are formed, which can lead to problems such as foreign objects getting caught between the stitching lines over long periods of use, and reduced productivity due to the multiple sewing steps during the manufacturing process. Therefore, active research is being conducted into technologies for thermally bonding various decorations and parts using adhesive films in a seamless manner.

[0004] On the other hand, adhesive films have a relatively high melting point and require relatively high temperatures during thermal bonding, which can cause damage to the adherend or fabric, so there is an increasing demand for materials that can maintain adhesion even at low temperatures and for short periods of heating.In addition, there is an increasing demand for adhesives with excellent elongation and elastic recovery properties in order to be used in areas where stretchability is required.

[0005] The thermoplastic polyurethane resin used in hot melt adhesive films is made by reacting a high molecular weight diol, such as a polyester diol or polyether diol, called a polyol, with a diisocyanate and a low molecular weight diol as a chain extender.These thermoplastic polyurethane hot melt adhesives are widely used in clothing applications due to the excellent physical properties of the polyurethane resin, which give them high tensile strength and elongation at break, as well as good texture and stretch recovery.

[0006] Among these, polyether-based polyurethanes have relatively low adhesive strength and mechanical properties compared to polyester-based polyurethanes, but are suitable for use as adhesives for clothing because they are inexpensive and have excellent flexibility, elongation, and hydrolysis resistance.

[0007] In addition, interest in environmentally friendly materials that can reduce greenhouse gas emissions such as carbon dioxide and secure carbon emission credits is growing. As a measure to this end, the polyurethane industry is moving toward switching to biobased raw materials to reduce the carbon footprint generated during the manufacturing process. In fact, plastics with a biocontent of 25% or more by weight are labeled as "bio-based plastics" and new product development and industrialization are being promoted. Currently available biopolyols can be divided into fatty acid-based polyols made from natural fat-based feedstocks such as castor oil, and polyester-based polyols made from monomers such as diacid and diol produced by fermentation using glucose as a feedstock. Of these, fatty acid-based polyols contain a mixture of primary and secondary alcohols, which creates a polarity difference compared to the petroleum-based polyols previously used. This reduces reactivity with diisocyanates, resulting in poor mechanical properties for the resulting polyurethane.

[0008] In addition, polyester polyols are typically made from 1,3-propanediol (1,3-PDO) and succinic acid, and while they offer excellent mechanical properties when applied to polyurethanes, they have weaknesses in low-temperature flexibility and hydrolysis resistance. In contrast, polytrimethylene ether glycol (PO3G), made from biomass-derived 1,3-PDO, offers the most practical alternative for reducing greenhouse gas emissions without compromising the quality of polyurethane, and research is ongoing to apply it industrially.

[0009] However, the polymerization method for PO3G involves reacting 1,3-PDO in the presence of an acid catalyst for a long period of time, which produces various oxidation by-products and low-molecular-weight oligomers. Among these, cyclic oligomers can cause numerous side effects in industrial applications. For example, in the case of polytetramethylene ether glycol (PTMG), an ether-based polyol, residual cyclic oligomers during film formation are known to cause problems such as a deterioration in mechanical properties and a blooming phenomenon in which they migrate to the surface of the product and precipitate as a white deposit on the film surface.

[0010] Therefore, there is a need for research into the industrial application of PO3G produced from biomaterials to polyurethane resins to ensure environmental friendliness, while also ensuring the quality to replace polyurethane resins that use existing petroleum-based polyols. Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention provides a polyurethane resin composition for hot melt adhesives that uses polytrimethylene ether glycol from which cyclic oligomers have been removed, and a method for producing the same. [Means for solving the problem]

[0012] To solve the above problems, there is provided a polyurethane resin composition comprising a reaction product of polytrimethylene ether glycol, a chain extender, and a diisocyanate, wherein the polytrimethylene ether glycol has a cyclic oligomer content of 0.3 wt % or less.

[0013] The present invention also provides a method for producing the polyurethane resin composition, comprising: polymerizing 1,3-propanediol to produce a product containing polytrimethylene ether glycol (Step 1); distilling the product at a temperature of 100 to 250°C and a pressure of 100.0 to 1.0 torr to remove cyclic oligomers (Step 2); mixing the polytrimethylene ether glycol-containing product from which the cyclic oligomers have been removed with a chain extender to produce a mixture (Step 3); and adding a diisocyanate compound, a catalyst, and a viscosity modifier to the mixture to produce a polyurethane resin (Step 4).

[0014] The present invention will be described in detail below.

[0015] Polyurethane adhesives are classified into polyester polyol-based polyurethanes and polyether polyol-based polyurethanes. The adhesive strength of an adhesive is determined by the properties of the adhesive itself and the bonding strength with the substrate. In particular, hot melt adhesives have better flowability at the bonding temperature as the melting temperature decreases, making them excellent for adhesive strength with substrates that have an uneven surface, such as textiles.

[0016] In general, polyester polyol-based polyurethane adhesives have excellent mechanical strength, but have a high melting temperature, which results in low bonding strength with the adhesive, and damage to fabrics due to high adhesive temperatures can be a problem.

[0017] The present invention relates to a polyurethane resin composition that uses polytrimethylene ether glycol (PGE), a polyether polyol, instead of the polyester polyol. The polyurethane resin composition according to the present invention has a low melting temperature, thereby solving the above-mentioned problems. Furthermore, compared to existing polytetramethylene glycol, the number of carbon atoms in the repeating unit is smaller, resulting in excellent adhesive elongation. Furthermore, it has been confirmed that PGE produced from biomass materials exhibits superior adhesive strength and flexibility compared to polyester biopolyols produced from other biomass materials.

[0018] On the other hand, polytrimethylene ether glycol (PGE) is obtained by condensation polymerization of 1,3-propanediol (1,3-PDO), but the product contains significant levels of oligomers, including cyclic oligomers, which cause blooming when applied to polyurethane adhesives, resulting in reduced mechanical properties and adhesive strength.

[0019] Therefore, the present invention is characterized in that the cyclic oligomers in the polytrimethylene ether glycol are selectively removed to reduce the content thereof to a certain level or less, thereby providing excellent adhesive strength and mechanical properties even when a polyurethane resin composition is prepared using the polytrimethylene ether glycol.

[0020] Preferably, the polytrimethylene ether glycol has a cyclic oligomer content of 0.3 wt% or less, 0.25 wt% or less, 0.2 wt% or less, 0.15 wt% or less, 0.1 wt% or less, 0.09 wt% or less, 0.08 wt% or less, 0.07 wt% or less, 0.06 wt% or less, or 0.05 wt% or less. Meanwhile, the term "cyclic oligomer" refers to a substance having a cyclic chemical structure in which 1,3-PDO loses functional groups due to an intramolecular reaction during condensation polymerization, and in particular, in the present invention, refers to highly volatile dimers to pentamers (polymerized from 2 to 5 monomers) that cause problems in product use. Furthermore, the theoretical lower limit of the cyclic oligomer content in polytrimethylene ether glycol is 0 wt%, but it may be, for example, 0.001 wt% or more, 0.002 wt% or more, 0.003 wt% or more, 0.004 wt% or more, or 0.005 wt% or more.

[0021] Preferably, the molecular weight distribution of the polytrimethylene ether glycol is 1.0 or more, 1.1 or more, 1.2 or more, 1.3 or more, 1.4 or more, or 1.5 or more; or 3.0 or less, 2.9 or less, 2.8 or less, 2.7 or less, 2.6 or less, or 2.5 or less. As will be described later, such a molecular weight distribution does not significantly decrease from the molecular weight distribution of polytrimethylene ether glycol produced from 1,3-PDO. In other words, this means that only components that affect the physical properties of polytrimethylene ether glycol have been effectively removed from the polytrimethylene ether glycol of the present invention.

[0022] Preferably, the polytrimethylene ether glycol has a 1,3-propanediol content of 0.1 wt% or less. More preferably, the 1,3-propanediol content in the polytrimethylene ether glycol according to the present invention is 0.09 wt% or less, 0.08 wt% or less, 0.07 wt% or less, 0.06 wt% or less, or 0.05 wt% or less. While the theoretical lower limit of the 1,3-propanediol content in polytrimethylene ether glycol is 0 wt%, it may be, for example, 0.001 wt% or more, 0.002 wt% or more, 0.003 wt% or more, 0.004 wt% or more, or 0.005 wt% or more.

[0023] Preferably, the number average molecular weight of the polytrimethylene ether glycol is 500 to 4000. More preferably, the number average molecular weight of the polytrimethylene ether glycol according to the present invention is 600 or more, 700 or more, 800 or more, 900 or more, or 1000 or more; and 3800 or less, 3600 or less, 3400 or less, 3200 or less, or 3000 or less.

[0024] Preferably, the chain extender comprises one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methylpentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, and neopentyl glycol. More preferably, the chain extender is 1,6-hexanediol.

[0025] The diisocyanate may be an aromatic isocyanate, an aliphatic diisocyanate, or an alicyclic diisocyanate, and may preferably be selected from the group consisting of naphthalene diisocyanate, diphenyl methane diisocyanate (MDI), toluene diisocyanate (TDI), tolidine diisocyanate (TODI), p-phenyl diisocyanate (PPDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (H12MDI), isophorone diisocyanate (IPDI), and a mixture of two or more thereof.

[0026] Preferably, the composition contains 50 to 89 parts by weight of the polytrimethylene ether glycol, 1 to 10 parts by weight of the chain extender, and 10 to 40 parts by weight of the diisocyanate compound. More preferably, the composition contains 51 parts by weight or more, 52 parts by weight or more, 53 parts by weight or more, 54 parts by weight or more, or 55 parts by weight or more of the polytrimethylene ether glycol; or 85 parts by weight or less, 84 parts by weight or less, 83 parts by weight or less, 82 parts by weight or less, 81 parts by weight or less, or 80 parts by weight or less of the chain extender. More preferably, the composition contains 2 parts by weight or more, 3 parts by weight or more, or 3.5 parts by weight or more, or 9 parts by weight or less, 8 parts by weight or less, or 7.5 parts by weight or less of the chain extender. More preferably, the diisocyanate compound is contained in an amount of 12 parts by weight or more, 13 parts by weight or more, 15 parts by weight or more, or 17 parts by weight or more; or 38 parts by weight or less, 36 parts by weight or less, 35 parts by weight or less, or 33 parts by weight or less.

[0027] Preferably, the polyurethane resin composition has a bio-content of 25 wt% or more, more preferably 30 wt% or more, 35 wt% or more, 40 wt% or more, 45 wt% or more, or 50 wt% or more. The polyurethane resin composition can be produced from polytrimethylene ether glycol produced by polymerizing biomass-derived 1,3-propanediol, and the bio-content refers to the carbon content of the bio-based raw materials relative to the total carbon content of the polyurethane resin composition.

[0028] The present invention also provides an adhesive film comprising the above-mentioned polyurethane resin composition.

[0029] The present invention further provides a hot melt adhesive comprising the adhesive film.

[0030] The present invention also provides a method for producing the above-mentioned polyurethane resin composition, which comprises the following steps: polymerizing 1,3-propanediol to produce a product comprising polytrimethylene ether glycol (Step 1); Step 2: removing cyclic oligomers by distilling the product at a temperature of 100 to 250°C and a pressure of 100.0 to 1.0 torr; mixing the product containing the polytrimethylene ether glycol from which the cyclic oligomers have been removed with a chain extender to produce a mixture (Step 3); and Step 4: Adding a diisocyanate compound, a catalyst, and a viscosity modifier to the mixture to prepare a polyurethane resin.

[0031] The present invention will be described in detail below for each step.

[0032] Phase 1 Step 1 of the present invention is the polymerization of 1,3-propanediol to produce a product comprising polytrimethylene ether glycol.

[0033] The reaction conditions of Step 1 are not particularly limited as long as it is a reaction for producing polytrimethylene ether glycol from 1,3-propanediol. Preferably, polytrimethylene ether glycol is produced by polycondensing 1,3-propanediol using a polycondensation catalyst.

[0034] Specifically, the polycondensation catalyst is selected from the group consisting of Lewis acids, Bronsted acids, super acids, and mixtures thereof. More preferably, the catalyst is selected from the group consisting of inorganic acids, organic sulfonic acids, heteropolyacids, and metal salts. Most preferably, the catalyst is selected from the group consisting of sulfuric acid, fluorosulfonic acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, phosphotungstic acid, phosphomolybdic acid, trifluoromethanesulfonic acid, 1,1,2,2-tetrafluoroethanesulfonic acid, 1,1,1,2,3,3-hexafluoropropanesulfonic acid, bismuth triflate, yttrium triflate, ytterbium triflate, neodymium triflate, lanthanum triflate, scandium triflate, and zirconium triflate. The catalyst may also be selected from the group consisting of zeolites, fluorinated alumina, acid-treated silica, acid-treated silica-alumina, heteropolyacids, and heteropolyacids supported on zirconia, titania, alumina, and / or silica. More preferably, sulfuric acid is used as the polycondensation catalyst.

[0035] The catalyst is preferably used at a concentration of 0.1 to 20 wt %, more preferably 1 to 5 wt %, based on the weight of the reaction mixture.

[0036] The polycondensation is preferably carried out at a temperature of 150 to 250° C., more preferably 160 to 220° C. Furthermore, the reaction is preferably carried out in the presence of an inert gas, and more preferably under nitrogen.

[0037] After the polycondensation, a hydrolysis reaction may be additionally carried out to remove the acid bonded to the polytrimethylene ether glycol, and a neutralization reaction may be additionally carried out following the hydrolysis reaction.

[0038] Phase 2 Step 2 of the present invention is a step of removing cyclic oligomers, 1,3-PDO, and oxidation by-products by distilling the product of Step 1. For this purpose, the thin-film distillation conditions of Step 2 are a temperature of 100 to 250°C and a pressure of 100.0 to 1.0 torr.

[0039] Meanwhile, the term "thin film distillation" as used herein refers to a distillation method that utilizes a thin film of a mixture to be separated, thereby increasing the surface area in contact with a heat source. For example, thin film distillation can be performed by forming a thin film on the inner wall of a thin film distiller using a physical force (e.g., a wiper) when the mixture flows into the thin film distiller, and then applying an appropriate temperature to the thin film using a heat source (e.g., heating media). Another advantage is that reducing the pressure inside the thin film distiller reduces the vapor pressure of the substance, allowing it to evaporate at a temperature lower than its original boiling point. Furthermore, a condenser can be installed inside the thin film distiller to recover the evaporated substance, i.e., the substance to be removed.

[0040] Furthermore, thin film distillation has the advantage that it can be applied continuously to the mixture to be separated. For example, thin film distillation can be performed continuously by continuously introducing the mixture to be separated into the top of the distiller and collecting the purified mixture from the bottom of the distiller.

[0041] The thin film distillation in step 2 is carried out at a temperature of 100 to 250°C, preferably 110°C or higher, 120°C or higher, 130°C or higher, 140°C or higher, or 150°C or higher; or 240°C or lower, 230°C or lower, 220°C or lower, 210°C or lower, or 200°C or lower. If the temperature is lower than 100°C, the distillation effect is small and it is difficult to remove the target substance, and if the temperature is higher than 250°C, thermal oxidation of polytrimethylene ether glycol may occur.

[0042] The thin film distillation in step 2 is carried out at a pressure of 100.0 to 1.0 torr, preferably 90.0 torr or less, 80.0 torr or less, 70.0 torr or less, 60.0 torr or less, or 50.0 torr or less, and more preferably 5.0 torr or more, 6 torr or more, 7 torr or more, 8 torr or more, 9 torr or more, or 10.0 torr or more. If the pressure exceeds 100.0 torr, the separation efficiency may be reduced, and if the pressure is less than 1.0 torr, the separation efficiency may be too high, resulting in the separation of components that should remain in the product, resulting in a low yield of the final product.

[0043] Meanwhile, the volatilized components in the thin film distillation vessel, i.e., the substances to be removed, can be discharged to the bottom of the thin film distillation vessel through a condenser, and the remaining purified mixture, i.e., the distillation residue, can be recovered separately.

[0044] Stage 3 Step 3 of the present invention is to mix the product containing polytrimethylene ether glycol from which cyclic oligomers have been removed with a chain extender to produce a mixture.

[0045] The content of the cyclic oligomer in the polytrimethylene ether glycol and the chain extender are described above.

[0046] The method for mixing the polytrimethylene ether glycol and the chain extender is not particularly limited, and generally, the materials can be mixed by pouring them into a mixer. At this time, it is preferable to maintain the temperature of the mixture at about 60°C to about 90°C, or about 65°C to about 85°C, so that the mixture can remain liquid.

[0047] Stage 4 Step 4 of the present invention is a step of preparing a polyurethane resin by adding a diisocyanate compound, a catalyst, and a viscosity modifier to the mixture of the polytrimethylene ether glycol and the chain extender.

[0048] Specific types of the diisocyanate compound are as described above, and it is preferable that the ratio (molar number of NCO functional groups of the diisocyanate compound / molar number of OH functional groups of the polyol compound and chain extender) is about 0.8 to about 1.2, about 0.9 to about 1.1, or about 0.95 to about 1.05.

[0049] The catalyst may be a bismuth-based catalyst, and examples of the bismuth-based catalyst include catalysts containing bismuth compounds such as bismuth octoate, bismuth naphthenate, bismuth propionate, bismuth neodecanoate, and bismuth trimeodecanate.

[0050] In addition, a viscosity modifier can be added to improve the reactivity or processability of the produced product, and dimethylformamide (DMF) is preferably used as the viscosity modifier. After adding the viscosity modifier, the reaction is continued until the viscosity reaches the target value. A reaction terminator is added, and the product is cooled to obtain a polyurethane resin composition. An alcohol, such as ethanol, is used as the reaction terminator. [Effects of the Invention]

[0051] As described above, the present invention can provide a polyurethane resin for a hot melt adhesive suitable for clothing by removing cyclic oligomers from polytrimethylene ether glycol, and a method for producing the same. DETAILED DESCRIPTION OF THE INVENTION

[0052] Hereinafter, preferred examples will be presented to aid in understanding the present invention. However, the following examples are merely illustrative of the present invention, and the scope of the present invention is not limited to the following examples.

[0053] In the following Production Examples, Examples and Comparative Examples, the physical properties were measured as follows.

[0054] 1) Molecular weight distribution (Mw / Mn) and total oligomer content (wt%) The polytrimethylene ether glycol produced in each of the following production examples was dissolved in THF (tetrahydrofuran) at a concentration of 1 wt%, and the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were calculated using gel permeation chromatography (manufacturer: WATERS, model: Alliance, detector: 2414 RI detector, column: Strygel HR 0.5 / 1 / 4) with polyethylene glycol as the standard substance. From the measured Mw and Mn, the molecular weight distribution and the content of low-molecular-weight oligomers with Mn of 400 or less were calculated.

[0055] 2) 1,3-PDO content (wt%) and cyclic oligomer content (wt%) 0.5 g of polytrimethylene ether glycol prepared in each preparation example was dissolved in 10 mL of methanol and measured using gas chromatography (model: Agilent 7890, column: DBWAX). 1 g of each reference substance was dissolved in 10 mL of methanol and further diluted according to the concentration, and measured using the standard reference to calculate the 1,3-PDO content (wt%) and cyclic oligomer content (wt%) contained in the polytrimethylene ether glycol.

[0056] 3) OHV 6 g of the polytrimethylene ether glycol prepared in each Preparation Example below and 15 mL of an acetylation reagent (acetic anhydride / pyridine = 10 / 40 vol%) were added to a 100 mL flask and reacted under reflux at 100°C for 30 minutes. After the reaction, the mixture was cooled to room temperature and 50 mL of distilled water was added. The reaction mixture was titrated with 0.5N KOH using an automatic titrator (manufactured by Metrohm, Titrino 716), and the OHV was calculated using the following equation 1.

[0057]

number

[0058] In the above formula 1, 56.11 means the molecular weight of KOH, 0.5 means the normal concentration of KOH, A is the amount of KOH solution dispensed for the blank test, B is the aliquot of KOH solution used to titrate the sample.

[0059] The measured OHV was converted into the average molecular weight (Mn) of the terminal group according to the following Equation 2.

[0060]

number

[0061] Production Example 1: Production of polyol 1) Production of Polyol A Step a) Biomass-derived 1,3-propanediol (15 kg) and sulfuric acid (150 g) were charged into a 20 L glass double-jacket reactor equipped with a Teflon stirrer and sparger, and the polymer was produced at 166°C for 16 hours under nitrogen sparging. Reaction by-products were removed through an overhead condenser.

[0062] Stage b) Deionized water (5 kg) was then added, and the resulting mixture was maintained at 95°C for 4 hours under nitrogen blowing to hydrolyze the acid ester formed during polymerization. After hydrolysis, 170 g of soda ash in 1000 mL of deionized water was added, and the mixture was heated to 80°C with stirring under a nitrogen stream. Neutralization was continued for 1 hour, and then the product was dried at 120°C under reduced pressure and filtered using a Nutche filter to obtain the polytrimethylene ether glycol product.

[0063] 2) Production of Polyol B A polytrimethylene ether glycol product was obtained by the same method as in the method for producing Polyol A, except that the reaction time in step a) was changed from 16 hours to 26 hours.

[0064] The physical properties of the prepared polyol A and polyol B are shown in Table 1 below.

[0065] [Table 1]

[0066] Production Example 2: Removal of cyclic oligomers by thin film distillation Each of the polyols produced in the above Production Examples was purified using a lab-scale thin-film distillation apparatus.

[0067] Specifically, the thin-film distillation equipment is a VTA VKL-70-4 model, a short-path distillation type in which a condenser is installed inside the distillation column, and the evaporation diameter and surface area are 70 mm and 0.04 m, respectively. 2The distillation column jacket was set to the appropriate temperature using a hot oil system, and the inside of the column was brought to the target vacuum level using a vacuum pump. Each sample was then fed into the top of the distillation column at the appropriate feed rate. At this time, the polytrimethylene ether glycol was formed into a thin film of uniform thickness inside the column using a mechanical stirrer equipped with a wiper. Volatilized low-molecular-weight substances were condensed in an internal condenser and discharged to the distillate side, and purified polytrimethylene ether glycol was discharged as residue.

[0068] Each produced polyol was subjected to a test at a feed rate of 1 kg / hr for 1 hour, and after the test, samples were taken and their physical properties were measured. The results are shown in Table 2 below.

[0069] [Table 2]

[0070] Example 1 61.78 wt% (50 mol%) of thin-film distilled polytrimethylene ether glycol (PO3G1000, Polyol C) with a molecular weight of 1000 and 7.30 wt% (50 mol%) of 1,6-hexanediol were added to a mixer and stirred at 80°C to maintain the liquid state. 30.92 wt% (100 mol% / OH:NCO = 1:1) MDI and the catalyst Bismuth trineodecanoate (300 ppm) were gradually added to the mixture without generating heat. Dimethylformamide (DMF) was added to adjust the viscosity, and the reaction was continued until the target viscosity was reached. Ethanol was added as a reaction terminator, and the mixture was cooled to below 40°C to produce a thermoplastic polyurethane resin. The resulting resin was bar-coated and dried in a hot air dryer at 80°C for 12 hours to produce adhesive films with thicknesses of 30-100 μm.

[0071] Example 2 A polyurethane resin and an adhesive film were produced in the same manner as in Example 1, except that the amounts of polytrimethylene ether glycol (PO3G2000, Polyol D) with a molecular weight of 2000, which was subjected to thin-film distillation, were changed to 76.37 wt% (50 mol%), 1,6-hexanediol 4.51 wt% (50 mol%), and MDI 19.11 wt% (100 mol% / OH:NCO=1:1).

[0072] Comparative Example 1 A polyurethane resin and an adhesive film were produced in the same manner as in Example 1, except that the amounts used were changed to 61.78 wt% (50 mol%) of polytrimethylene ether glycol (PO3G1000, Polyol A) with a molecular weight of 1000, 7.30 wt% (50 mol%) of 1,6-hexanediol, and 30.92 wt% of MDI (100 mol% / OH:NCO=1:1).

[0073] Comparative Example 2 A polyurethane resin and an adhesive film were produced in the same manner as in Example 1, except that the amounts used were changed to 76.37 wt% (50 mol%) of polytrimethylene ether glycol (PO3G2000, Polyol B) with a molecular weight of 2000, 4.51 wt% (50 mol%) of 1,6-hexanediol, and 19.11 wt% of MDI (100 mol% / OH:NCO=1:1).

[0074] Comparative Example 3 A polyurethane resin and an adhesive film were produced in the same manner as in Example 1, except that the amounts used were changed to 61.78 wt% (50 mol%) of polytetramethylene ether glycol (PTMG1000) with a molecular weight of 1000, 7.30 wt% (50 mol%) of 1,6-hexanediol, and 30.92 wt% MDI (100 mol% / OH:NCO=1:1).

[0075] Comparative Example 4 A polyurethane resin and an adhesive film were produced in the same manner as in Example 1, except that the amounts of polytetramethylene ether glycol (PTMG2000) with a molecular weight of 2000 was changed to 76.37 wt% (50 mol%), 1,6-hexanediol to 4.51 wt% (50 mol%), and MDI to 19.11 wt% (100 mol% / OH:NCO=1:1).

[0076] Comparative Example 5 A polyurethane resin and an adhesive film were obtained in the same manner as in Example 1, except that the amounts of Poly(Succinic acid / 1,3-PDO) with a molecular weight of 1000 was changed to 61.78 wt% (50 mol%), 1,6-hexanediol to 7.30 wt% (50 mol%), and MDI to 30.92 wt% (100 mol% / OH:NCO=1:1).

[0077] Comparative Example 6 A polyurethane resin and an adhesive film were obtained in the same manner as in Example 1, except that the amounts of Poly(Succinic acid / 1,3-PDO) with a molecular weight of 2000 was changed to 76.37 wt% (50 mol%), 1,6-hexanediol to 4.51 wt% (50 mol%), and MDI to 19.11 wt% (100 mol% / OH:NCO=1:1).

[0078] Comparative Example 7 A polyurethane resin and an adhesive film were obtained in the same manner as in Example 1, except that the amounts of polybutylene adipate diol (PBA-1000) with a molecular weight of 1000, 61.78 wt% (50 mol%), 1,6-hexanediol 7.30 wt% (50 mol%), and MDI 30.92 wt% (100 mol% / OH:NCO=1:1) were added.

[0079] Comparative Example 8 A polyurethane resin and an adhesive film were obtained in the same manner as in Example 1, except that the amounts of polybutylene adipate diol (PBA-2000) with a molecular weight of 2000 was changed to 76.37 wt% (50 mol%), 1,6-hexanediol to 4.51 wt% (50 mol%), and MDI to 19.11 wt% (100 mol% / OH:NCO=1:1).

[0080] Experimental Example The polyurethane resins or adhesive films prepared in the above examples and comparative examples were evaluated for physical properties as follows, and the results are shown in Tables 3 and 4 below.

[0081] 1) Tensile strength, elongation, 100% modulus, 300% modulus and elastic modulus The tensile strength, elongation, 100% modulus, and 300% modulus were measured using a Universal Testing Machine (Model: Instron 4465, manufacturer: Instron) based on ASTM D412 (test specimen width: 20 mm, length: 100 mm, thickness: 50 μm, tensile speed: 500 mm / min).

[0082] 2) Koefler Melting Point The Köfler melting point was measured using a Köfler Hot Bench (Karg Industrietechnik, Germany). Specifically, a film measuring 50 μm thick, 1 cm wide, and 20 cm long was placed on a 30 cm long metal plate with a temperature gradient ranging from room temperature to 230°C for 30 seconds, and then lifted up. The temperature of the metal plate at the location where the film broke was recorded as the melting point (the temperature of the metal plate was measured using six substances with melting points between 69.7°C of stearin and 226.5°C of saccharin).

[0083] 3) Bio content (wt%) The bio-based carbon content of the polyurethane resins produced in the Examples and Comparative Examples relative to the total carbon content was measured.

[0084] 4) Adhesive strength A TPU fabric (VENTWIN, VENTWIN (registered trademark)), the adhesive films produced in the examples and comparative examples, and a water-repellent treated polyester fabric (Sewing House, ANS-217) were bonded in this order using a heat press at 140°C for 20 seconds, and the strength was measured using a universal testing machine (500N load cell) according to the method specified in ASTM D 1876 (the width of the bonded joint was 25 mm, and the pulling speed was 10 inches / min).

[0085] [Table 3]

[0086] As shown in Table 3, the polyurethane adhesive films containing polytrimethylene ether glycol with residual cyclic oligomers (Comparative Examples 1 and 2) exhibited a blooming phenomenon in which the oligomers migrated to the surface, resulting in a decrease in the physical properties and adhesive strength of the adhesive film. However, the polyurethane adhesive films according to the present invention (Examples 1 and 2) prepared using polytrimethylene ether glycol containing a certain level or less of cyclic oligomers did not exhibit the blooming phenomenon and showed improved flexibility and adhesive strength.

[0087] [Table 4]

[0088] In Table 4, Comparative Examples 3, 4, 7, and 8, which are polyurethane resin adhesive films containing existing petroleum-based polyols, show that polyester polyols provide superior adhesive strength compared to polyether polyols, but have poor flexibility and are therefore limited in their use as adhesives for clothing that is subject to frequent deformation. Furthermore, due to the bonding properties of polyester, polyurethane adhesives tend to have a somewhat high melting point, which can cause damage to the fabric being bonded.

[0089] It was confirmed that Examples 1 and 2 according to the present invention exhibited adhesive strength at the same level as Comparative Examples 7 and 8, which contained petroleum-based polyester polyol, and also had high elongation values and excellent flexibility. It was also confirmed that Examples 1 and 2 according to the present invention exhibited superior elongation and adhesive strength compared to Comparative Examples 4 and 5, which used bio-polyester polyol.

Claims

1. Polytrimethylene ether glycol, a chain extender, and including reaction products of diisocyanates, The polytrimethylene ether glycol has a cyclic oligomer content of 0.3 wt % or less. Polyurethane resin composition.

2. The polytrimethylene ether glycol has a cyclic oligomer content of 0.05 wt % or less. The polyurethane resin composition according to claim 1.

3. The molecular weight distribution (Mw / Mn) of the polytrimethylene ether glycol is 1.0 to 3.

0. The polyurethane resin composition according to claim 1.

4. The polytrimethylene ether glycol has a 1,3-propanediol content of 0.1 wt % or less. The polyurethane resin composition according to claim 1.

5. The number average molecular weight of the polytrimethylene ether glycol is 500 to 4,000. The polyurethane resin composition according to claim 1.

6. The chain extender includes one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methylpentanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, and neopentyl glycol; The polyurethane resin composition according to claim 1.

7. The diisocyanate may be naphthalene diisocyanate, diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), tolidine diisocyanate (TODI), p-phenyl diisocyanate (PPDI), hexamethylene diisocyanate (HDI), dicyclohexylmethane diisocyanate (H12MDI), or isophorone diisocyanate (IPDI). diisocyanate), and mixtures of two or more thereof; The polyurethane resin composition according to claim 1.

8. 50 to 89 parts by weight of the polytrimethylene ether glycol, 1 to 10 parts by weight of a chain extender, and Contains 10 to 40 parts by weight of a diisocyanate compound, The polyurethane resin composition according to claim 1.

9. The bio content is 25 wt% or more; The polyurethane resin composition according to claim 1.

10. An adhesive film comprising the polyurethane resin composition according to any one of claims 1 to 9.

11. The adhesive film according to claim 10, Hot melt adhesive.

12. polymerizing 1,3-propanediol to produce a product comprising polytrimethylene ether glycol (Step 1); Step 2: Distilling the product at a temperature of 100 to 250°C and a pressure of 100.0 to 1.0 torr to remove cyclic oligomers; mixing the product containing the polytrimethylene ether glycol from which the cyclic oligomers have been removed with a chain extender to produce a mixture (Step 3); and and (4) adding a diisocyanate compound, a catalyst, and a viscosity modifier to the mixture to prepare a polyurethane resin. A method for producing the polyurethane resin composition according to any one of claims 1 to 7.

13. The temperature of step 2 is 150°C to 200°C. A method for producing the polyurethane resin composition according to claim 12.

14. The pressure in step 2 is 50.0 torr to 1.0 torr. A method for producing the polyurethane resin composition according to claim 12.

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