KR20230040476A - Manufacturing method of solvent-free polyurethane resin adhesive - Google Patents

Abstract

For a method for manufacturing a solvent-free polyurethane resin additive, the technical idea of the present invention is to comprise: a main agent and a curing preparing step which mixes polyol and glycol to manufacture a main agent, and mixes isocyanate and polyol to manufacture a curing agent, thereby preparing the main agent and the curing agent, respectively; an additive preparing step which mixes a catalyst, an oxide prevention agent, a light stabilizer, and NO_x prevention agents to prepare an additive; a mixing and discharging step which injects the main agent, the curing agent, and the additive into each injector of a 3-way mixing head, and mixes the same while discharging the same to form a solvent-free polyurethane resin; and a resin aging step which ages the solvent-free polyurethane resin at a high temperature to form a solvent-free polyurethane resin additive. Accordingly, the solvent-free polyurethane resin additive, which is eco-friendly since organic solvents are not used and has an excellent physical property, can be obtained.

Description

Solvent-free polyurethane resin adhesive manufacturing method {Manufacturing method of solvent-free polyurethane resin adhesive}

The present invention relates to a method for manufacturing a solvent-free polyurethane resin adhesive, and more particularly, to a method for manufacturing a solvent-free polyurethane resin adhesive that is environmentally friendly because it does not use an organic solvent and exhibits excellent physical properties.

Recently, when manufacturing shoes, automobile seats, etc., some products are manufacturing seamless type products using hot melt adhesive films to prevent needle marks from being left. In the process of manufacturing these hot-melt adhesive films, solvent-type polyurethane resins have been used for a long time. In the case of solvent-type polyurethane resins, the physical properties required for an adhesive film such as abrasion resistance and bending resistance are excellent, as well as adhesion and appearance characteristics. It has the advantage of being

However, solvent-type polyurethane resin used in the process of manufacturing adhesive films uses organic solvents that are regulated as carcinogens, such as dimethylformamide (DMF), methyl ethyl ketone (MEK), and toluene. These organic solvents act as environmental hazards and have a problem in that their use is restricted by global environmental regulations in accordance with changes in the industrial environment. In addition, there is a problem that the above organic solvents are a major cause of fire in the workplace due to their high volatility.

Therefore, in order to respond to the strengthening regulations, related industries are developing water-dispersion polyurethane resins that can replace solvent-type polyurethane resins, but when water-dispersion polyurethane resins are processed into adhesive films, the resin migrates to the adhesive film. (migration), the touch becomes hard, the elasticity is lowered, and there are disadvantages in that wrinkles are formed in the adhesive film.

Korea Intellectual Property Office Registration Patent No. 10-2174657

The present invention has been made to solve the above problems, and is to provide a solvent-free polyurethane resin adhesive manufacturing method that is environmentally friendly because it does not use an organic solvent and exhibits excellent physical properties.

The above object is to prepare a subject by mixing polyol and glycol, prepare a hardener by mixing isocyanate and polyol, and prepare the subject and hardener, respectively; Additive preparation step of preparing by mixing a catalyst, antioxidant, light stabilizer and NO _x inhibitor; A mixing and discharging step of injecting the main agent, the curing agent and the additives into separate inlets in a 3-way mixing head, and mixing them simultaneously with discharging to form a solvent-free polyurethane resin; and a resin aging step of aging the solvent-free polyurethane resin at a high temperature to form a solvent-free polyurethane resin adhesive.

Here, in the additive preparation step, it is preferable to prepare the additive by further including a silicone-based leveling agent and a non-silicone-based wetting agent, and in the mixing and discharging step, the discharge temperature of the three-way mixing head is 120° C. and the discharge speed is 12 m. It is preferable that the main agent, the curing agent, and the adhesive are respectively discharged by controlling / min.

As described above, according to the present invention, since no organic solvent is used, it is possible to obtain a solvent-free polyurethane resin adhesive that is environmentally friendly and exhibits excellent physical properties.

1 is a flowchart of a method for manufacturing a solvent-free polyurethane resin adhesive according to an embodiment of the present invention;
2 is a photograph of a three-way mixing head,
3 is a graph showing the change in viscosity of a resin using a conventionally used amine catalyst or organometallic catalyst;
4 is a graph showing the change in viscosity according to the content of the thermally sensitive catalyst at room temperature;
5 is a graph showing the change in viscosity according to the content of the thermally sensitive catalyst at the activation temperature;
6 is a graph showing the change in viscosity according to the content of the thermally sensitive catalyst at overtemperature;
7 is a photograph of a specimen subjected to 10,000 bending tests;
8 is a photograph of a film aging test specimen,
9 is a graph showing the results of a heat aging test of a film;
10 is a photograph of a specimen showing the results of a UV aging test of a film,
11 is a graph of UV aging test results of a film,
12 is a graph of the result of comparative analysis of the degree of NCO extinction by temperature and time by FT-IR,
13 is an FT-IF graph for analysis of unreacted substances of a solvent-free polyurethane resin adhesive,
14 is a glass transition temperature (T _g ), crystallization temperature (T _c ), melting temperature (T _m ) measurement graph,
15 is a graph showing the results of analyzing the solvent-free adhesive PY-GCMS,
16 is a graph showing the results of TGA-GCMS analysis of solvent-free adhesives;
17 to 21 are test reports of non-solvent type adhesives.

Hereinafter, the technical idea of the present invention will be described in more detail using the accompanying drawings. Since the accompanying drawings are only examples shown to explain the technical idea of the present invention in more detail, the technical idea of the present invention is not limited to the form of the accompanying drawings.

1 is a flowchart of a method for manufacturing a solvent-free polyurethane resin adhesive according to an embodiment of the present invention, FIG. 2 is a photograph of a three-way mixing head, and FIG. 3 is a viscosity of a resin using a conventionally used amine catalyst or organometallic catalyst. Figure 4 is a graph showing the change in viscosity according to the content of the heat-sensitive catalyst at room temperature, Figure 5 is a graph showing the change in viscosity according to the content of the heat-sensitive catalyst at the activation temperature, Figure 6 is a graph showing the change in viscosity at overtemperature A graph showing the change in viscosity according to the content of the sensitive catalyst, FIG. 7 is a photograph of a specimen subjected to a 10,000 bending test, FIG. 8 is a photograph of a film aging test specimen, FIG. 9 is a graph of the result of a heat aging test of a film, and FIG. 11 is a graph of UV aging test results of a silver film, FIG. 12 is a graph showing the result of comparative analysis of NCO extinction by temperature and time by FT-IR, and FIG. FT-IF graph for analysis of unreacted substances of solvent-free polyurethane resin adhesive, Figure 14 is a glass transition temperature (T _g ), crystallization temperature (T _c ), melting temperature (T _m ) measurement graph, Figure 15 is a useless A graph showing the results of analyzing the formulated adhesive PY-GCMS, FIG. 16 is a graph showing the TGA-GCMS analysis results of the solvent-free adhesive, and FIGS. 17 to 21 are test reports of the non-solvent adhesive.

It is preferable to prepare the physical properties of the solvent-free polyurethane resin adhesive according to the present invention to be similar to those of the currently used solvent-type polyurethane resin adhesive having excellent physical properties. In particular, the shape of the resin for applying the solvent-free polyurethane resin adhesive is advantageously maintained in a liquid state at room temperature, and it is preferred to have a low viscosity so that coating is possible at 30 to 40 ° C. That is, it is an object of the present invention to manufacture a solvent-free polyurethane resin adhesive capable of exhibiting high physical properties while having a low glass transition temperature (T _g ).

As shown in FIG. 1, the solvent-free polyurethane resin adhesive manufacturing method according to the present invention includes a main agent and a curing agent preparation step (S100), an additive preparation step (S200), a mixing discharge step (S300), and a resin aging step (S400). ).

First, the subject and hardener preparation step (S100) means a step of preparing a subject and a hardener, respectively, by preparing a subject by mixing polyol and glycol, and preparing a hardener by mixing isocyanate and polyol.

As the polyol, one selected from the group consisting of polyester polyol, polyether polyol, polycarbonate diol, and mixtures thereof is prepared. As shown in Table 1, these polyols include adipate, polycaprolactone (PCL), polypropylene glycol (PPG), polytetramethylene glycol (PTMG), and polyethylene glycol (PEG). ), etc. can be applied, but is not limited thereto.

division designation Raw material polyester polyol adipate adipic acid + glycol polycaprolactone (PCL) caprolactone polyether polyol Polypropylene glycol (PPG) PO(propylene oxide) Polytetramethylene glycol (PTMG) Tetrahydrofuran (THF) Polyethylene glycol (PEG) Ethylene oxide (EO) polycarbonatediol PC 1,6HG + ethylene carbonate

Isocyanates are aromatic isocyanates such as toluene diisocyanate (TDI), 4,4-diphenyl methane diisocyanate (MDI), xylene diisocyanate (XDI), and aliphatic isocyanate hexa It is selected from the group consisting of hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), which is an alicyclic isocyanate, cyclohexane diisocyanate (H ₁₂ MDI), and mixtures thereof. The characteristics of these isocyanates are shown in Table 2.

division designation M.P (℃) B.P(℃) Mw aromatic TDI toluene diisocyanate 13 120 174 MDI 4,4-diphenyl methane diisocyanate 37 175 250 XDI xylene diisocyanate -7 188 aliphatic HDI hexamethylene diisocyanate 113 168 alicyclic IPDI isophorone diisocyanate -60 158 223 _H12 MDI Cyclohexane diisocyanate 12 262

Glycol is ethylene glycol, 1,4-butanol, 1,6-hexanediol, neopentyl glycol, diethylene glycol ), 3-methyl-1,5-pentanediol (3-methyl-1,5-pentanediol), and is preferably selected from the group consisting of mixtures thereof, and the physical properties of these glycols can be confirmed through Table 3.

designation M.P (℃) B.P(℃) Mw ethylene glycol -12.9 197.3 62.07 1,4-butanol 230 90.12 1,6-hexanediol 250 118.17 neopentyl glycol 129.1 208 104.15 diethylene glycol 244 106.12 3-methyl-1,5-pentanediol <-10 249 118.17

Among them, a polycarbonate diol copolymer having a molecular weight of 1,000 to 2,000 is preferred as the polyol for manufacturing the main material. If the molecular weight exceeds the molecular weight, it is difficult to manufacture an adhesive without using an organic solvent, so it has a low viscosity. In order to maintain, it must consist of a molecular weight of 1,000 to 2,000. Also, as the glycol, 1,4-butanediol is most preferred. The isocyanate for preparing the curing agent is preferably 4,4-MDI and C-MDI, and the polyol mixed therewith is preferably a polycarbonate diol copolymer having a molecular weight of 1,000 to 2,000.

In the case of the solvent-type polyurethane resin according to the prior art, processing is performed after additionally diluting the organic solvent to adjust the viscosity appropriate for the addition of additives and roll coating, but in the case of the non-solvent-type polyurethane resin as in the present invention Since the liquid is used immediately, additives must be prepared in advance.

That is, when a solvent-type polyurethane resin is properly mixed with a crosslinking agent and a solvent-type polyurethane resin having a certain level of molecular weight, overall physical properties are uniformly formed due to volatilization of the organic solvent and relatively long pot life. On the other hand, in the case of solvent-free polyurethane resin, since organic solvents that can lower the viscosity are not separately used, polyol and glycol crosslinking agents of unimaginably low molecular weight must be used to adjust the viscosity for coating and working. .

50 parts by weight of each of the main agent and the curing agent are prepared to correspond to a 1:1 weight ratio.

The additive preparation step (S200) means a step of mixing and preparing a catalyst, an antioxidant, a UV stabilizer, a UV absorber, and an NO _x inhibitor.

When a catalyst is added during the process of forming a solvent-free polyurethane resin adhesive, even a small amount of catalyst can cause an explosive reaction because it does not contain an organic solvent that dilutes the main material and the curing agent. Therefore, in the present invention, it is preferable to use a thermally sensitive catalyst having low reactivity at low temperature or room temperature and increasing reactivity at high temperature. Here, it is preferable to prepare 0.1 part by weight of the heat-sensitive catalyst.

When such a catalyst is not used or used in a small amount, pot life and tacky time for each process become longer, thereby reducing the line speed and increasing the aging time, thereby reducing the productivity of the adhesive. On the other hand, if the catalyst is used in excess, the pot life and time required for each process can be reduced, but there is a problem in that it is difficult to secure uniformity of physical properties due to the mixture of over-reactants and unreacted materials in the roll coater. Therefore, it is desirable to set the optimum amount of catalyst to be used by adjusting the working time and the holding time for each process in the line where uniformity of physical properties is secured. This can increase the line speed and increase production efficiency by reducing aging time as much as possible.

Antioxidants are added to prevent the adhesive from being oxidized by atmospheric oxygen or other exhaust gases, Octadecyl 3-(3,5-di-t-butyl-4-hydroxy phenyl)-propionate, 4,4'-Bis(alpha,alpha-dimethylbenzyl)di-phenylamine, polymerized 1,2-dihydro-2,2, 4-trimethyl quinoline, 2,5-di-t-butyl-4-methylphenol, Hydroquinoline, N,N'-diphenyl-p-phenylenediamine, Tri(nonylatedphenyl)phosphite, 2-Mercaptobenziaidazole, N-Cyclohexy thiophthal ilnide and mixtures thereof It can be selected from the group consisting of 0.3 parts by weight of these antioxidants can be prepared.

The light stabilizer is added to delay the discoloration of the adhesive by ultraviolet rays (UV), heat, etc., and it is preferable to prepare 1.0 parts by weight of the UV stabilizer and 1.0 part by weight of the UV absorber. In addition, it is preferable that 0.5 parts by weight of the NO _x inhibitor is prepared. In some cases, 0.3 parts by weight of a silicone-based leveling agent and 0.3 parts by weight of a non-silicone-based wetting agent may be additionally added.

After mixing various types of additives, prepare them separately from the main agent and curing agent.

The mixing and discharging step (S300) means a step of injecting the main agent, curing agent, and additives into separate inlets in a 3-way mixing head, and then mixing them simultaneously with discharging to form a solvent-free polyurethane resin. do.

Instead of forming a polyurethane resin by pre-mixing the subject and hardener formed through the subject and hardener preparation step (S100) and the additive formed through the additive preparation step (S200), in a state where the subject, hardener, and additives are separately provided When production of an adhesive is necessary, it is mixed to prepare a polyurethane resin.

When forming the solvent-type polyurethane resin, since the organic solvent exists, the polyurethane resin is not cured even if it is mixed in advance. However, since the present invention does not contain organic solvents, as shown in FIG. 2, the main agent, curing agent, and additives are separately injected into the 3-way mixing head in advance to prevent them from mixing with each other, and only when necessary, the three-way mixing head The mixing head is driven to form a solvent-free polyurethane resin.

At this time, the discharge temperature of the three-way mixing head is adjusted to 120 ° C and the discharge speed is adjusted to 12 m / min so that the polyurethane resin is discharged and aligned in a flat film shape at the same time. In some cases, if the ratio of the main ingredient, hardener, and additives needs to be adjusted, the discharge speed of the three-way mixing head can be individually adjusted rather than adjusting the addition amount. In addition, the discharge temperature can be individually adjusted according to the composition.

The resin aging step (S400) means a step of forming a solvent-free polyurethane resin adhesive by aging the solvent-free polyurethane resin at a high temperature.

When the main agent, curing agent and additives are mixed and discharged through the mixing and discharging step (S300), the mixed solvent-free polyurethane resin is discharged and then aligned in a film shape. This solvent-free polyurethane resin is aged at a high temperature. When the solvent-free polyurethane resin adhesive is formed. At this time, the aging temperature is preferably 80 ° C. or higher, and the aging time is preferably 48 hr or higher.

Hereinafter, embodiments of the present invention will be described in more detail.

<Comparative Example 1>

Solvent-type polyurethane resin adhesive uses poly(1,4-butylene ethylene diethylene glycol adipate) and poly(1,4-butylene ethylene glycol adipate) as polyols, and uses 1,4-butanediol and Neopentyl glycol as glycols. , Polyurethane resin was prepared using toluene diisocyanate as isocyanate. The organic solvents used here are dimethylformamide (DMF) and methyl ethyl ketone (MEK), and antioxidants and light stabilizers are added as additives. A linear polymer having a molecular weight of about 10,000 to 20,000 was synthesized by reacting the polyol, glycol, and diisocyanate, and an antioxidant and a light stabilizer were additionally added due to vulnerability to yellowing.

In the case of a two-component polyurethane resin, since a film cannot be formed alone even if the organic solvent is removed, the film properties are exhibited only when a crosslinked structure is created by adding a crosslinking agent. Therefore, after volatilizing the organic solvent, set the green tacky of the resin according to the line condition, and proceed with adhesion to the backing cloth and backing hotmelt thermoplastic polyurethane. In general, it takes 24 to 48 hours at 50 to 60° C. for a two-component polyurethane resin to completely cure or crosslink.

As such, the polyurethane resin adhesive prepared using an organic solvent has physical properties shown in Table 4 below.

100% modulus (kgf/cm²) elongation (%) tensile strength (kgf/cm2) 35 to 45 300~400 250 to 350

<Comparative Example 2>

An experiment was conducted to prepare a solvent-free polyurethane resin adhesive using the compositions used in the manufacture of a solvent-type polyurethane resin adhesive. For the polyurethane resin adhesive, Poly(1,4-butylene ethylene diethylene glycol adipate) and Poly(1,4-butylene ethylene glycol adipate) were used as polyols, 1,4-butanediol and Neopentyl glycol were used as glycols, and isocyanate prepared a polyurethane resin using toluene diisocyanate. The organic solvents used here are dimethylformamide (DMF) and methyl ethyl ketone (MEK), and antioxidants and light stabilizers are added as additives.

As a manufacturing process, a polyol and glycol having a molecular weight of 2,000 were sequentially added to a stirrer and stirred at 70° C. for 2 hours to form a main agent. Then, isocyanate was added to the stirrer separately, and after raising the temperature to 60° C., polyol having a molecular weight of 2,000 was similarly added. Thereafter, a curing agent was formed by stirring at 70° C. for 3 hours.

Comparative Example 2 viscosity
(cps/30℃) hydroxyl value
(mgKOH/g) NCO cont. Mixing ratio subject 1,100 208 - 100 curing agent 1,900 - 17.5 100

Physical property result Comparative Example 1 Comparative Example 2 tacky time (min) 5 to 8 8 to 10 pot life (min) 60-90 16-20 Adhesive strength (kg/2.5cm) 3.9 2.3 film properties 100% modulus (kgf/cm²) 42 27 elongation (%) 370 360 tensile strength (kgf/cm2) 300 190

As a result of using the composition applied to the solvent-type polyurethane resin adhesive as it is to the non-solvent-type polyurethane resin adhesive and using it on a film, the structural pattern during the reaction is different, resulting in poor physical properties overall, even considering tacky time and pot life. A difference can be seen. In the case of elongation, it can be said to be good around the target value, but low result values were shown in the strength of the film and 100% modulus, and in particular, it was confirmed that the adhesive strength was very weak. This is because solvent-type polyurethane resin adhesives grow linear molecules to have a network structure as a cross-linking agent, whereas non-solvent-type polyurethane resin adhesives cannot increase molecular weight compared to viscosity because they must match the appropriate viscosity during processing, resulting in a random reaction of small molecules This is considered to be the result of the difference.

In order to overcome such reactive and structural disadvantages, the applicable composition was identified, and the direction of changing the hydroxyl value of the subject and the NCO cont. of the curing agent. It is intended to confirm the composition according to the composition and the difference in physical properties according to the mixing ratio by making changes.

<Example 1>

In order to select a composition suitable for a solvent-free polyurethane resin adhesive, experiments were conducted with various compositions and mixing ratios. In Example 1, physical properties were confirmed after selecting various subjects in a state in which a specific curing agent was prepared. Table 7 shows the subject matter of various compositions, and Table 8 shows one curing agent selected for mixing with the subject matter.

subject polyol glycol Topic 1-1 polytetramethylene ether glycol
Company K, Mw: 1,000 1,4-butanediol Topic 1-2 polytetramethylene ether glycol
Company K, Mw: 2,000 1,4-butanediol Topic 1-3 polytetramethylene ether glycol
Company K, Mw: 3,000 1,4-butanediol Topics 1-4 polytetramethylene ether glycol
Company H, Mw: 2,000 1,4-butanediol

curing agent isocyanate polyol curing agent 1 4,4-diphenyl methane diisocyanate polytetramethylene ether glycol
Company K, Mw: 2,000

After preparing such a subject and curing agent, the respective physical property values can be confirmed through Table 9, and the resulting values of the physical properties of the solvent-free polyurethane resin adhesive and the film to which the adhesive is applied can be confirmed through Table 10. there is. Here, Example 1-1 mixes curing agent 1 and subject 1-1, Example 1-2 mixes hardener 1 and subject 1-2, and Example 1-3 mixes hardener 1 and subject 1-3. Examples 1-4 are mixtures of Curing Agent 1 and Subject 1-4.

viscosity
(cps/30℃) hydroxyl value
(mgKOH/g) NCO cont.
(%) Mixing ratio
(Subject: Hardener) curing agent 1 1,600 - 18.3 - Topic 1-1 700 200 - 100:92 Topic 1-2 650 223 - 100:93 Topic 1-3 700 225 - 100:94 Topics 1-4 750 220 - 100:92

Physical property result Example 1-1 Example 1-2 Example 1-3 Example 1-4 tacky time (80℃*min) 8 to 10 8 to 10 10 to 12 8 to 10 pot life (30℃*min) 16-20 16-20 20 to 25 16-20 Adhesive strength (kg/2.5cm) 2.2 2.0 1.8 2.1 film properties 100% modulus (kgf/cm²) 33 29 28 29 elongation (%) 320 340 360 330 tensile strength (kgf/cm2) 270 250 230 260

Table 11 shows the subject matter of various compositions, as in Table 9, Table 12 shows the physical property values of each subject, and Tables 13 and 14 are solvent-free polyurethane resin adhesives and adhesives prepared using curing agent 1 and subject matter. It shows the resulting value of the physical properties of the film applied.

subject polyol glycol Topics 1-5 poly(1.4-butanediol adipate)
Mw: 1,000 1,4-butanediol Topics 1-6 poly(methylene glycol adipate)
Mw: 1,000 1,4-butanediol Topic 1-7 poly(neopentyl glycol adipate)
Mw: 1,000 1,4-butanediol Topics 1-8 poly(1,6-hexanediol adipate)
Mw: 1,000 1,4-butanediol Topics 1-9 polycarbonatediol (1,6-hd homo)
Mw: 1,000 1,4-butanediol Topics 1-10 polycarbonatediol (1,5pd/1,6hd copolymer)
Mw: 1,000 1,4-butanediol Topic 1-11 polypropylene glycol (1,4-hd) 1,4-butanediol Topic 1-12 polypropylene glycol (gloh) 1,4-butanediol

viscosity
(cps/30℃) hydroxyl value
(mgKOH/g) NCO cont.
(%) Mixing ratio
(Subject: Hardener) curing agent 1 1,600 - 18.3 - Topics 1-5 800 220 - 100:92 Topics 1-6 700 221 - 100:92.5 Topic 1-7 750 223 - 100:93 Topics 1-8 730 224 - 100:93.5 Topics 1-9 680 225 - 100:94 Topics 1-10 700 215 - 100:90 Topic 1-11 650 220 - 100:92 Topic 1-12 690 219 - 100:91.5

Physical property result Example 1-5 Example 1-6 Examples 1-7 Examples 1-8 tacky time (80℃*min) 8 to 10 8 to 10 8 to 10 8 to 10 pot life (30℃*min) 20 to 24 16-20 20 to 25 16-20 Adhesive strength (kg/2.5cm) 2.4 2.2 2.3 1.9 film properties 100% modulus (kgf/cm²) 30 30 29 31 elongation (%) 300 340 350 365 tensile strength (kgf/cm2) 280 280 270 255

Physical property result Examples 1-9 Examples 1-10 Example 1-11 Examples 1-12 tacky time (80℃*min) 8 to 10 8 to 10 10 to 12 10 to 12 pot life (30℃*min) 16-20 16-20 20 to 24 20 to 24 Adhesive strength (kg/2.5cm) 2.3 2.4 1.4 1.5 film properties 100% modulus (kgf/cm²) 32 33 20 21 elongation (%) 345 330 400 410 tensile strength (kgf/cm2) 290 290 150 160

As a result of fixing the curing agent and applying various materials for each polyol, it was confirmed that the polycarbonatediol (copolymer) type exhibited the best physical properties. In particular, since carbonate has a structure having strengths in its own mechanical properties and aging properties, synthesis was performed to select the subject of Examples 1-10 as a composition in selecting the overall composition. That is, polycarbonate diol copolymers having a molecular weight of 1,000 corresponding to subjects 1-10 were selected as polyols, and 1,4-butanediol was selected as glycols.

<Example 2>

Through Example 1, it was confirmed that subject matter 1-10 had the best physical properties, and subject matter 1-10 was fixed as the subject matter, and a curing agent of various components was synthesized and an experiment was conducted to select a hardener. Table 15 shows the curing agents of various components, and Tables 16 to 19 show the physical properties of the curing agents.

curing agent isocyanate polyol Hardener 2-1 4,4-MDI
C-MDI polytetramethylene ether glycol
Company K, Mw: 2,000 Hardener 2-2 4,4-MDI
L-MDI polytetramethylene ether glycol
Company K, Mw: 2,000 Hardener 2-3 4,4-MDI
L-MDI, C-MDI polytetramethylene ether glycol
Company K, Mw: 2,000 Hardener 2-4 4,4-MDI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000 Hardener 2-5 4,4-MDI
C-MDI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000 Hardener 2-6 4,4-MDI
L-MDI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000 Hardener 2-7 4,4-MDI
L-MDI, C-MDI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000 Hardener 2-8 MI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000 Hardener 2-9 MI
L-MDI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000 Hardener 2-10 4,4-MDI
MI polycarbonatediol
(1,5pd/1,6hd copolymer)
Mw: 1,000

viscosity
(cps/30℃) hydroxyl value
(mgKOH/g) NCO cont.
(%) Mixing ratio
(Subject: Hardener) Hardener 2-1 500 - 17.8 100:93 Hardener 2-2 500 - 18.1 100:91 Hardener 2-3 610 - 17.6 100:93.5 Hardener 2-4 630 - 16.5 100:100 Hardener 2-5 580 - 16.7 100:99 Hardener 2-6 570 - 16.5 100:100 Hardener 2-7 700 - 16.8 100:98 Hardener 2-8 680 - 16.9 100:97 Hardener 2-9 710 - 17.0 100:97 Hardener 2-10 750 - 17.2 100:95.5

Here, Example 2-1 mixes base material 1-10 and curing agent 2-1, Example 2-2 mixes curing agent 2-2, Example 2-3 mixes curing agent 2-3, and Example 2-4 is mixed with curing agent 2-4, Example 2-5 is mixed with curing agent 2-5, Example 2-6 is mixed with curing agent 2-6, Example 2-7 is mixed with curing agent 2-7, Example 2 -8 is a mixture of a curing agent 2-8, Example 2-9 is a mixture of a curing agent 2-9, Example 2-10 is a solvent-free polyurethane resin adhesive formed by mixing a curing agent 2-10 and physical properties of the film to which the adhesive is applied It shows the result value.

Physical property result Example 2-1 Example 2-2 Example 2-3 Example 2-4 tacky time (80℃*min) 8 to 10 8 to 10 8 to 10 8 to 10 pot life (30℃*min) 20 to 24 16-20 16-20 16-20 Adhesive strength (kg/2.5cm) 2.2 2.2 2.3 2.3 film properties 100% modulus (kgf/cm²) 29 28 29 31 elongation (%) 300 340 350 365 tensile strength (kgf/cm2) 280 280 270 255

Physical property result Example 2-5 Example 2-6 Examples 2-7 Example 2-8 tacky time (80℃*min) 8 to 10 8 to 10 8 to 10 8 to 10 pot life (30℃*min) 16-20 16-20 16-20 20 to 25 Adhesive strength (kg/2.5cm) 2.2 2.4 2.2 2.3 film properties 100% modulus (kgf/cm²) 31 34 32 29 elongation (%) 365 310 320 350 tensile strength (kgf/cm2) 275 295 290 270

Physical property result Example 2-9 Examples 2-10 tacky time (80℃*min) 8 to 10 8 to 10 pot life (30℃*min) 16-20 16-20 Adhesive strength (kg/2.5cm) 1.9 2.2 film properties 100% modulus (kgf/cm²) 31 32 elongation (%) 365 320 tensile strength (kgf/cm2) 255 290

As a result of fixing the subject to 1-10 and checking the physical properties of each isocyanate (classified for initial injection and later dilution) and each polyol, 4,4-MDI and L-MDI types of curing agents showed the best physical properties. Could know. Based on these results, additional tests were conducted to improve physical properties based on 1-10 for the main material and 2-6 for the curing agent.

<Example 3>

Figure 3 shows the case of using an amine catalyst or an organometallic catalyst conventionally used to prepare a polyurethane resin adhesive, after adding 0.1 parts by weight of a Bi-based catalyst, a Zr-based catalyst, and a tertiary amine catalyst, respectively. The change in viscosity was confirmed. As a result, it can be confirmed that an exothermic reaction occurs at the same time as mixing, and the reaction progress rate is accelerated. As a result, a mixture of unreacted and overreacted materials occurs in the roll coater, and the semi-dry time tends to decrease. That is, even if the amount of catalyst is reduced from the current condition in order to meet the pot life and tacky time, it is judged that it will not be easy to control the activation of the reaction.

Therefore, Example 3 was carried out by applying a thermally sensitive catalyst having low reactivity at room temperature and increasing activity when the temperature rises. In the combination of subject 1-10 and curing agent 2-6, 0.05 part by weight, 0.1 part by weight, and 0.2 part by weight of the heat-sensitive catalyst were added to subject 1-10, respectively, and after mixing the curing agent 2-6 thereto, room temperature (25 ℃ ), the degree of viscosity increase was confirmed respectively on the activation temperature (60 ℃) and overtemperature (80 ℃). Figure 4 is a graph showing the change in viscosity according to the content of the thermally sensitive catalyst at room temperature, Figure 5 is a graph showing the change in viscosity according to the content of the thermally sensitive catalyst at the activation temperature, Figure 6 is a graph showing the viscosity according to the content of the thermally sensitive catalyst at overtemperature This is a graph showing the change.

When using a heat-sensitive catalyst, the reaction proceeds at a temperature lower than the activation temperature (60 ° C), but it can be seen that the viscosity increase is very slow, and the viscosity at the activation temperature (60 ° C) increases after 9 min. At the temperature (80 ° C.), it can be seen that the increase in viscosity increases after 5 to 7 min. Therefore, in the roll coater at room temperature, the reaction rate was maintained as stable as the state in which no heat-sensitive catalyst was added. It was confirmed that the line setting could be established.

Table 20 confirms the tacky time and pot life according to the amount of the heat-sensitive catalyst used. As a result of comparison according to the amount of heat-sensitive catalyst added to Subjects 1-10 and Curing Agents 2-6, 0.1 part by weight of the heat-sensitive catalyst was added. is considered to be the best.

thermosensitive catalyst
0.05 part by weight thermosensitive catalyst
0.1 part by weight thermosensitive catalyst
0.2 parts by weight tacky time(80℃*min) 4 to 5 2-3 1~2 pot life(30℃*min) 8 to 10 7-8 2-3

<Example 4>

In order to increase flexibility, polytetramethylene ether glycol (PTMEG), which has excellent ductility and elasticity, is added to polycarbonatediol copolymers having a molecular weight of 1,000 corresponding to subjects 1-10, and curing agent 2- In 6, PTMEG was additionally added as a polyol to form a solvent-free polyurethane resin adhesive. The physical properties of these adhesives can be confirmed through Tables 21 and 22.

viscosity
(cps/30℃) hydroxyl value
(mgKOH/g) NCO cont.
(%) Mixing ratio subject 550 208 - 100 curing agent 1,600 - 18.1 88

Physical property result Example 4 tacky time (80℃*min) 2-3 pot life (30℃*min) 7-8 Adhesive strength (kg/2.5cm) 3.4 film properties 100% modulus (kgf/cm²) 34 elongation (%) 340 tensile strength (kgf/cm2) 310

It was confirmed that the adhesive prepared with this composition had good overall physical properties such as adhesive strength, and in particular, the flexibility appeared similar to that of conventional adhesives. This can be confirmed through a photograph of a specimen subjected to 10,000 bending tests in FIG. 7 .

<Example 5>

Based on Example 4, the optimal prescription amount of each of the UV stabilizer, UV absorber, antioxidant, and NO _x inhibitor was determined for the aging property test. In the test specimen, the composition corresponding to the optimal ratio was confirmed by adjusting the addition amount as shown in Table 23 in order to confirm the accurate aging degree. Through this, when 0.3 parts by weight of antioxidant, 1.0 part by weight of UV stabilizer, 1.0 part by weight of UV absorber, and 0.5 part by weight of NOx inhibitor were used, the physical properties of the solvent-type polyurethane resin adhesive were equivalent or good. This corresponds to a result that meets the physical property standards applied to shoes or automobile seats.

additive 0.0 parts by weight 0.3 parts by weight 0.5 parts by weight 0.7 parts by weight 1.0 parts by weight antioxidant × ◎ ◎ ◎ ◎ UV stabilizer × △ ○ ○ ◎ UV absorber × △ ○ ○ ◎ NO _x inhibitor × ○ ◎ ◎ ◎

*◎: very good, ○: good, △: average, ×: bad

After mixing these additives, the aging property test of the film was performed to confirm the light aging resistance property. Therefore, the film strength retention rate after heat aging can be confirmed through Table 24, FIGS. 8 and 9. Table 24 shows the comparison result of the heat resistance test, FIG. 8 corresponds to a photograph of the film aging test specimen, and FIG. 9 is a graph showing the heat resistance aging test result of the film.

100% MOD showed a retention rate of 48% in the case of solvent-type adhesive (binder) and 50% in the case of solvent-free adhesive. , In the case of tensile strength, the solvent-type adhesive showed a retention rate of 46% and the non-solvent-type adhesive showed a retention rate of 52%.

heat resistance test
120℃ solvent-based adhesive Example 5 100% MOD elongation tensile strength 100% MOD elongation tensile strength existing 40 360 340 34 340 310 1 day 33 354 246 29 325 204 3 days 23 315 175 24 378 187 5 days 20 301 168 21 374 176 7 days 19 296 157 17 380 162

In addition, as shown in Table 25, the adhesion test results confirmed that the retention rate of the non-solvent type adhesive was better.

120℃*7days Solvent-based adhesive (kg/2.5cm) Example 5 (kg/2.5 cm) existing 3.9 3.4 3 days 3.8 3.3 5 days 3.69 3.5 7 days 3.5 3.1 retention rate 89.7% 91.1%

The film strength retention rate after UV aging can be confirmed through Table 26 and FIG. 10. In particular, in the case of FIG. 10, it corresponds to a photograph of a specimen showing the UV aging test results of the film.

UV test
3kw*45℃ solvent-based adhesive Example 5 100% MOD elongation tensile strength 100% MOD elongation tensile strength existing 40 380 340 34 340 310 1 hour 39 363 295 34 535 291 2 hours 37 363 276 32 550 279 4 hours 35 352 261 31 560 265 6 hours 34 313 245 30 368 252

As shown in FIG. 11, 100% MOD showed a retention rate of 85% in the case of solvent-type adhesive (binder) and 88% in the case of solvent-free adhesive, and in the case of elongation, solvent-type adhesive was 87%, solvent-free adhesive showed a retention rate of 108%, and in terms of tensile strength, the solvent-type adhesive showed a retention rate of 72% and the solvent-free adhesive showed a retention rate of 81%.

The prescription amount was set through the aging physical property test for the optimal amount of additives from the theoretical mixing ratio adjustment, and in terms of physical properties, it is judged to be equal to or superior to existing solvent-type polyurethane resin adhesives except for elongation.

<Example 6>

In order to disperse the surface tension of the solvent-free polyurethane resin adhesive, various leveling agents were mixed in various ratios to confirm optimal leveling agent conditions. Table 27 shows the surface smoothness results according to the prescription amount of the leveling agent. Through this, it is judged that it is appropriate to use the leveling agent B or C, but rather than the siloxane-based leveling agent C, which can cause problems in adhesion, it is a silicone-based leveling agent. (silicon) It is determined that it is most preferable to add 0.3 parts by weight of leveling agent B.

additive 0.0 parts by weight 0.1 part by weight 0.3 parts by weight 0.5 parts by weight leveling agent A × △ △ ◎ leveling agent B × △ ◎ ◎ leveling agent C × △ ◎ ◎

*◎: very good, ○: good, △: average, ×: bad

<Example 7>

In order to increase the adhesive force with the adherend, there is a method of weakening the surface tension with the adherend to increase wetting or introducing a coupling agent to increase the adhesive force between the backing materials. The solvent-free polyurethane resin adhesive of the present invention was tested using a wetting agent using a hot melt type TPU as an adherend. Table 28 shows the results of the wetting effect according to the prescription amount of the wetting agent. As a result of the test, wetting agent B was the best compared to the amount used and corresponds to a non-silicone-based wetting agent, so the effect on adhesion can be minimized. Here, the adhesion unit in Table 31 corresponds to kg/2.5 cm.

additive 0.0 parts by weight 0.1 part by weight 0.3 parts by weight 0.5 part by weight Wetting Agent A 3.4 3.5 3.7 3.7 wetting agent B 3.4 3.75 3.8 3.8 wetting agent C 3.4 3.5 3.75 3.8

<Example 8>

Line conditions for preparing the main agent, curing agent, and additives for producing a solvent-free polyurethane resin adhesive are shown in Table 29, and the length of the chamber connected to the three-way mixing head corresponds to 30 m. Among them, the case where the temperature of the chamber is 120° C. and the speed of the chamfer is 12 m/min corresponds to the most desirable line condition.

coater gap (mm) chamber temp. (℃) chamber speed
(m/min) tacky time 0.15 80 12 slow/slow 0.15 80 15 slow/slow 0.15 100 12 slow/slow 0.15 100 15 slow/good 0.15 120 12 good 0.15 120 15 fast/good 0.15 130 12 fast/good 0.15 130 15 fast/fast

<Example 9>

The result of comparative analysis of the degree of NCO extinction by temperature and time by FT-IR by manufacturing a non-solvent type polyurethane resin adhesive as a film can be confirmed through FIG. It is preferable that aging is performed at a temperature of 80° C. and 48 hr or more.

As a result of performing FT-IF to analyze unreacted substances of the solvent-free polyurethane resin adhesive prepared through this process, as shown in FIG. 13, it can be confirmed that the isocyanate peak disappears around 2260 cm ^-1 . Through this, it can be seen that the content of NCO, an unreacted material, is much lower than that of commercially available solvent-free adhesives. In addition, characteristic peaks present in urethane bonds, such as NH and C=O, were observed, indicating successful polymerization.

The prepared solvent-free polyurethane resin adhesive was measured for one glass transition temperature (T _g ), crystallization temperature (T _c ), and melting temperature (T _m ) through DSC thermogram measurement, and as a result of the measurement, as shown in FIG. The glass transition temperature was -61.06 °C, the crystallization temperature was -4.69 °C, and the melting temperature was 19.93 °C. Only one value was measured. It was confirmed that the non-solvent type polyurethane resin adhesive prepared through this did not show a peak due to unreacted materials.

In addition, the gas generated as the temperature rises was analyzed through TGA-GC/MS analysis. As shown in FIG. 14, it was confirmed that the prepared solvent-free adhesive was decomposed in two stages, which was determined to be that the decomposition of the urethane group occurred first and then the decomposition of the soft segment. Specifically, the initial decomposition before 190 ° C was believed to be due to the evaporation of residual monomers, which was observed to be less than 1%, confirming that there was almost no residual monomer as an unreacted material. In addition, decomposition occurring after the initial temperature of 190 ° C is due to decomposition of the urethane bond, and decomposition occurring after 414 ° C is regarded as decomposition of the polyol component.

Figure 15 shows the results of analyzing PY-GCMS at 300 ° C to confirm the monomers and VOCs remaining in the solvent-free adhesive, and as a result of comparison with the database, 1,4-butanediol and diphenylmethanedi due to decomposition of urethane bonds Isocyanate was detected and peaks caused by benzene derivatives were observed, but stable volatile solvents were not detected even at high temperatures.

Figure 16 shows the TGA-GCMS analysis of the solvent-free adhesive, and the monomers and VOCs remaining in the developed solvent-free adhesive were confirmed by raising the temperature from 30 ° C to 1,000 ° C at 10 ° C per minute. As a result of the analysis, the peaks caused by DMF, MEK, chloroform, acetone, and benzene-type organic solvents, which are known to emit gases below 200 ° C, do not appear, confirming that there is almost no volatilization of organic solvents or the amount of remaining monomers. there was. As a result of comparison with the database, as mentioned above, gas generation due to decomposition of urethane bonds after 300 ° C and decomposition of polyol after 400 ° C were observed.

The solvent-free polyurethane resin adhesive according to the present invention has no DMF detected through the test reports of FIGS. 17 to 21, VOCs emission less than 0.01ppm, bending resistance no abnormality at 100,000 times, curing time 48 hours or less, flame retardancy 0cmm, adhesion It was clearly confirmed that the strength was 2.5 kgf/cm or more. That is, since the present invention does not use an organic solvent, it is possible to obtain a solvent-type polyurethane resin adhesive having excellent eco-friendly characteristics and excellent adhesive performance as well as solvent-type adhesives.

The present invention is not limited to the above embodiments, and the scope of application is diverse, and various modifications and implementations are possible without departing from the gist of the present invention claimed in the claims.

S100: subject and curing agent preparation step
S200: Additive preparation step
S300: Mixed discharge step
S400: Resin aging step

Claims (3)

A subject and hardener preparation step of preparing a subject by mixing polyol and glycol, preparing a hardener by mixing isocyanate and polyol, and preparing the subject and hardener, respectively;
Additive preparation step of preparing by mixing a catalyst, antioxidant, light stabilizer and NO _x inhibitor;
A mixing and discharging step of injecting the main agent, the curing agent and the additives into separate inlets in a 3-way mixing head, and mixing them simultaneously with discharging to form a solvent-free polyurethane resin; and
A method for producing a solvent-free polyurethane resin adhesive comprising a; resin aging step of forming a solvent-free polyurethane resin adhesive by aging the solvent-free polyurethane resin at a high temperature. According to claim 1,
The additive preparation step,
Solvent-free polyurethane resin adhesive manufacturing method, characterized in that for preparing the additive further comprising a silicone-based leveling agent and a non-silicone-based wetting agent. According to claim 1,
The mixed discharge step,
The solvent-free polyurethane resin adhesive manufacturing method, characterized in that the main agent, the curing agent and the adhesive are respectively discharged by adjusting the discharge temperature of the three-way mixing head to 120 ° C and the discharge speed to 12 m / min.

Images