KR20080045436A - Composition for thermoplastic polyurethane elastomer blend with excellent high frequency weldability - Google Patents

Abstract

A polyurethane elastomer blend composition is provided to ensure excellent reactivity to high frequency and to be superior in adhesion by high frequency and cutting property by a forming mold. A polyurethane elastomer blend composition includes (a) 50-95wt% of polyurethane elastomer prepared by polymerizing ester-based polyol having a number average molecular weight of 600-2500, a diol-based chain extender, and isocyanate and (B) 5-50wt% of methacrylate/butadiene/styrene-based resins. The polyurethane elastomer blend composition has a shore hardness of 70-95 A, a tensile strength of 220 kgf/cm^2 or less, and a tearing resistance of 90 kgf/cm or less.

Description

Composition for thermoplastic polyurethane elastomer blend with excellent high frequency weldability

1 is a view schematically illustrating the principle of high frequency welding.

※ Explanation of code about main part of drawing ※

1: electromagnetic wave 2: electrode

3: vibration

The present invention relates to a thermoplastic polyurethane elastomer blend composition having excellent high frequency processability. More specifically, the present invention exhibits excellent responsiveness to high frequency, and is excellent in adhesiveness by high frequency and cutting property by molding mold, so that it can replace high frequency adhesion using conventional PVC and synthetic rubber, and high frequency workability. This excellent thermoplastic polyurethane elastomer blend composition relates to.

In general, thermoplastic polyurethane resins are composed of isocyanates, polyols and chain extenders. Among them, polyols are divided into polyesters, polyethers, and polycarbonates according to intramolecular bonding.

Such polyurethane elastomers can be largely prepared in a batch or continuous reaction equipment, and catalysts such as dibutyl tin dilaurate are used to further improve the completion of the reaction. In addition, in order to increase the UV, heat resistance, hydrolysis stability of the resin, and the like to add an additive for each purpose to prepare a polyurethane elastomer.

Thermoplastic polyurethane elastomer has characteristics such as cold resistance, flex resistance, wear resistance, oil resistance, antibacterial resistance, thermal processing resistance, high frequency adhesiveness, etc., and has excellent tensile strength, elongation, etc., in particular, its use in injection molding, extrusion, etc. The use of the logs varies. In addition, it has a wide range of Shore hardness (Shore 60A to Shore 75D), and its use range is widened to replace PVC and rubber products through environmentally friendly composition and excellent physical properties.

On the other hand, the high frequency processing referred to in the present invention relates to the bonding and mold molding using a high frequency welding machine, the high frequency processing technology is made in the following manner.

High frequency in high frequency welding means an electromagnetic wave 1 having a frequency of 27.12 MHz. As shown in FIG. 1, the poles of both electrodes 2 are changed by the frequency. At this time, in the case of a material having a polarity among the materials positioned between the electrodes, the electromagnetic force is received by the pole which is rapidly switched, and the vibration 3 is rapidly caused by the property of being attracted to the opposite pole.

By the above principle, the high frequency reactivity of the polymer material is affected by the polarity of the material. Especially, the properties of PVC, thermoplastic polyurethane elastomer, etc. are excellently expressed, and in the nonpolar polymer material such as polypropylene and polyethylene, There is little effect. The polymer molecules polarized by the vibration generate frictional heat, and the molten resin is adhered by the heat.

In order to exhibit excellent high frequency characteristics, first, it must include polar molecules, and second, it must be easily deformed due to melting or softening at low temperature, and third, it must be easily cut because of high physical properties.

The following equation is about the high frequency reactivity of the polymer material.The higher the DLF value is, the higher the high frequency reactivity is.It is inactive at 0.05 or less, weak activity at 0.05 ~ 0.1, high frequency processing at 0.1 or higher, and suitable for high frequency processing at 0.2 or higher. Known. Table 1 shows the high frequency reactivity of each polymer.

DLF (dielectric loss factor) = (dielectric constant constant) × (dielectric loss tangent)

Dielectric loss factor (G: Good, F: Normal, P: Bad, N: None) ABS polymer 0.025 F-P Acetal 0.025 F-P Epoxy 0.12 F Melamine 0.2 G Phenylformaldehyde 0.2 G Polycarbonate 0.03 F-P polyester 0.05 F Polyethylene 0.0008 N Polypropylene 0.001 N Polyamide 0.013 P polystyrene 0.001 N PTFE ⁽¹⁾ 0.0004 N Polyurethane 0.4 G PVC ⁽²⁾ film (ductile) 0.4 G TPE ⁽³⁾ 0.13 F silicon 0.009 P-N

(1) PTFE: polytetrafluoroethylene

(2) PVC: polyvinyl chloride

(3) TPE: thermoplastic elastomer (mainly styrene-butadiene copolymer)

Source: JD Ferry, Viscoelastic Properties of Polymers (New York Wiley, 1970) and S Saito and T Narajiman Journal of Applied Polymer Science 2: 1959, 93.

Currently, PVC is widely used for high frequency bonding, and some polyurethane elastomers and synthetic rubbers are also used. PVC is widely used due to the convenience of processing and cost advantages, but is increasingly regulated due to the environmental hazards of plasticizers such as phthalates. In order to use for this purpose, PVC has a low softening point and a high physical property. In the case of urethane elastomer, the first and second conditions described above are satisfied, but high physical properties such as tensile strength and tear strength have limited application of high frequency applications. In addition, synthetic rubber resins, such as styrene-butadiene rubber, which are considered to be PVC substitutes, have relatively low transparency and thus are not widely used.

Accordingly, the present inventors have made efforts to improve the disadvantages of the thermoplastic polyurethane elastomer in the conventional high frequency processing. As a result, in order to improve burrs and cutting surfaces generated after high frequency work, MBS-based resins are compounded in a certain component ratio to general thermoplastic polyurethane elastomers to lower tensile strength and elongation of thermoplastic polyurethane elastomers, Good quality was achieved by removing the burrs.

Accordingly, one aspect of the present invention is to provide a polyurethane elastomer blend composition having excellent reactivity to high frequencies.

Another aspect of the present invention is to provide a polyurethane elastomer blend composition excellent in adhesiveness by high frequency and cutting property by molding mold.

A polyurethane elastomer blend composition according to one preferred embodiment of the present invention is:

(a) 50 to 95% by weight of a polyurethane elastomer obtained by polymerizing an ester polyol having a number average molecular weight of 600 to 2500, a diol chain extender, and an isocyanate; And

(b) 5 to 50% by weight of methacrylate / butadiene / styrene (MBS) resin;

Characterized in that it comprises a.

The polyurethane elastomer blend composition preferably has a Shore hardness of 70 A to 95 A, a tensile strength of 220 kgf / cm 2 or less, and a tear strength of 90 kgf / cm or less.

The ester polyol is preferably poly (3-methylpentyl adipate), poly (1,4-butylene adipate), poly (ethylene adipate), poly (ethylene-butylene adipate), poly (ethylene Diethylene glycol adipate), poly (hexylene-butylene adipate), poly (diethylene glycol adipate), poly (1,6-hexylene adipate) and mixtures thereof have.

The diol chain extender is preferably 1,2-ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol , 1,4-cyclohexanedimethanol and mixtures thereof.

The isocyanate is preferably methylene diphenyl diisocyanate, 2,4-toluene diisocyanate, naphthalene diisocyanate, xylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, isophorone Group consisting of diisocyanate, paraphenylene diisocyanate, 3,3'-toluene-4,4'-diisocyanate, 1,6-hexamethylene diisocyanate, methylene-bis (4-cyclohexyl isocyanate) and mixtures thereof Can be selected from.

The MBS-based resin preferably has a core-shell structure, and more preferably, in the core-shell structure, methacrylate may be included in the shell portion and a copolymer of styrene and butadiene may be included in the core portion.

The polyurethane elastomer blend composition may also further comprise an additive selected from the group consisting of UV stabilizers, antioxidants, lubricants, and combinations thereof.

The polyurethane elastomer blend compositions are also suitable for use in high frequency processing.

Hereinafter, the thermoplastic polyurethane elastomer blend composition of the present invention will be described in more detail.

Polyurethane elastomer blend composition according to a preferred embodiment of the present invention is 50 to 95% by weight of a polyurethane elastomer obtained by polymerizing an ester polyol having a number average molecular weight of 600 to 2500, a diol chain extender and an isocyanate, and methacrylate It contains 5-50 weight% of / butadiene / styrene (MBS) type resin.

Among the components constituting the polyurethane elastomer, there are various kinds of polyols such as polyester-based, polyether-based, and polycarbonate-based, but in the present invention, an ester-based polyol which is widely used and inexpensive is selected. The ester polyol is, for example, poly (3-methylpentyl adipate), poly (1,4-butylene adipate), poly (ethylene adipate), poly (ethylene-butylene adipate), poly (ethylene -Diethylene glycol adipate), poly (hexylene-butylene adipate), poly (diethylene glycol adipate), poly (1,6-hexylene adipate) can be used alone or in combination.

Such ester-based polyols are those having a number average molecular weight of 600 to 2500. If the number average molecular weight is less than 600, there is a high possibility that reaction control and quality deterioration occur in the polyurethane production step. Crystallinity is increased, and when compounding with MBS resin, smooth flow inside the compound is not achieved, and a problem of failing to secure basic transparency in the polyurethane stage occurs.

The chain extender used in the present invention is a diol-based chain extender, for example 1,2-ethylene glycol, 1,2-propylene glycol 1,3-propylene glycol, 1,4-butanediol, 1,5-pentane It can be used individually or in mixture of diol, 1, 6- hexanediol, and 1, 4- cyclohexane dimethanol.

In addition, the isocyanate used in the present invention is methylene diphenyl diisocyanate, 2,4-toluene diisocyanate, naphthalene diisocyanate, xylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate Alone, in isophorone diisocyanate, paraphenylene diisocyanate, 3,3'-toluene-4,4'-diisocyanate, 1,6-hexamethylene diisocyanate and methylene-bis (4-cyclohexyl isocyanate), or Can be mixed.

The amount of ester-based polyols, diol-based chain extenders, and isocyanates used as a reaction raw material in the polymerization of the polyurethane elastomer is not particularly limited, but is preferably 40 to 60% by weight and 5 to 15% by weight, respectively, for ease of high frequency processing. It is preferable to use in% and 25-45 weight%.

On the other hand, methacrylate / butadiene / styrene (hereinafter referred to as MBS) -based resin is generally intended to reinforce the impact resistance of engineering plastics such as polycarbonate, PVC, polyethylene terephthalate (PET) It is produced through emulsion polymerization as a resin additive used for the purpose. MBS resin used in the present invention preferably has a core-shell (CORE-SHELL) structure, the surface of the shell portion is a cross-linked form of a methacrylate-based resin having good compatibility with other resins, The core component varies depending on the purpose of impact reinforcement, but the styrene-butadiene copolymer is included in the MBS-based resin used in the present invention.

The above-mentioned polyurethane elastomer and MBS resin are included in the blend composition of the present invention in amounts of 50 to 95% by weight and 5 to 50% by weight, respectively. Here, when the content of the MBS-based resin is less than 5% by weight, the physical properties such as tensile strength and tear strength are not sufficiently lowered, and when the content of the MBS-based resin exceeds 50% by weight, the viscosity increases sharply at a temperature in the processing temperature range. .

On the other hand, in general, it is difficult to maintain transparency when compounding two or more resins, but the polyurethane elastomer and the MBS-based resin used in the present invention have similar refractive indices in compounding (for example, about 1.53 to 1.54) ), There is no difficulty in maintaining transparency, and the impact resistance can be improved by using MBS resin.

On the other hand, in order to further enhance the properties such as UV stability, heat dissipation resistance, appearance, etc. according to the actual application purpose by further compounding by using a UV stabilizer, antioxidants, lubricants, etc., it is possible to secure more excellent high-frequency processability. In this case, the additive component may be used in an amount of about 1 part by weight or less based on 100 parts by weight of the polyurethane elastomer blend, but is not particularly limited thereto.

On the other hand, the raw materials of the specific components and contents described above may be compounded through a single screw or twin screw extruder, a continuous reaction extruder, a kneader or the like generally used in the art for uniform mixing. In addition, if the method for uniform mixing can be applied and is considered to be within the scope of the present invention.

According to one preferred embodiment of the present invention, by using a continuous reaction extruder melt kneaded the reaction raw material for polyurethane elastomer production into pellets, followed by injection molding through a compounding step of melt kneading with MBS resin after drying at room temperature After sufficient stabilization, various mechanical properties can be evaluated.

Such polyurethane elastomer blend compositions of the invention preferably have a Shore hardness of 70A to 95A, which is usually in a commercially available range.

On the other hand, when Shore hardness 85A is generally used, tensile strength according to ASTM D412 is 300kgf / cm or more and tear strength is 90kgf / cm or more. ) Is not commonly used due to the high frequency of occurrence. On the contrary, in the case of the polyurethane elastomer blend composition according to the present invention, the tensile strength is lowered to 220 kgf / cm 2 or less, and the tear strength is lowered to 90 kgf / cm or less, thereby facilitating cutting and significantly reducing the occurrence of burrs. Could.

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Examples 1-6 and Comparative Examples 1-2

Thermoplastic polyurethane resins have polyols, isocyanates and chain extenders in a continuous reaction extruder (Werner amp; Pfleiderer ZSK 58 twin-screw extruder) with a raw material meter and a dough block of 30% of the total screw. In each case, the polyurethane elastomer was polymerized at a reaction temperature of 190 to 220 ° C. At this time, the screw rotation speed is 250 rpm, the catalyst was used dibutyltin dilaurate 150 ppm. The thermoplastic polyurethane resin polymerized in the continuous extruder was made into chips using a pelletizer and dried at 70 ° C. for 5 hours using a dehumidifying dryer (Conair SC60, Inlet air dew point = -50 ° C.). To obtain a polyurethane elastomer.

The polyurethane elastomer obtained in the above experiment was attached to the raw material metering device, and the dough block was continuously added to the continuous biaxial compounder (TEM), which is 30% of the total screw, according to the contents shown in the following Table 3, and then 180 to Compounding was carried out at an instrument temperature of 200 ° C. At this time, the screw rotation speed was 100, and 0.2 parts by weight of stabilizer was added for UV stability, thermal stability, and processing stability, respectively.

ingredient unit Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 MDI ⁽¹⁾ weight% 30.67 30.66 30.67 30.67 30.66 30.66 30.67 30.67 Polyols 1 ⁽²⁾ weight% 65.18 0 65.18 65.18 0 0 65.18 65.18 Polyol 2 ⁽³⁾ weight% 0 64.55 0 0 64.55 64.55 0 0 BD ⁽⁴⁾ weight% 4.14 4.77 4.14 4.14 4.77 4.77 4.14 4.14

(1) MDI (diisocyanate): methylene diphenyl diisocyanate

(2) Polyol 1: Poly (butylene adipate), Mw 1000

(3) Polyol 2: Poly (ethylene-butylene adipate), Mw 1000

(4) BD (chain extender): 1,4-butanediol

Blend content unit Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Polyurethane weight% 100 100 80 70 80 70 80 70 MBS Resin 1 ⁽¹⁾ weight% 0 0 20 30 20 30 0 0 MBS Resin 2 ⁽²⁾ weight% 0 0 0 0 0 0 20 30

(1) MBS resin 1: EM-700 (LG Chemical)

(2) MBS resin 2: C-132 (Mitsubishi Rayon)

Experimental Example

Polyurethane elastomer blends prepared in Examples 1 to 6 and Comparative Examples 1 and 2 were used as a square specimen of 120 mm × 120 mm × 2.0 mm at a temperature of 180 to 200 ° C. using an injection machine (Engel, clamping force-70 ton). After injection, the physical properties were measured according to the following ASTM, and the samples prepared in each example and the comparative example were extruded to a thickness of 0.5 mm by an extruder (60, single screw), and then a high frequency welding machine (shing high frequency, 10 KW, hydraulic, twin head) and mold (10 mm x 100 mm, cutter blade height 0.7 mm) and the results are shown in Table 4 below.

[Measurement of physical properties]

-Tensile strength, elongation: measured according to ASTM D412

-Tear strength: measured according to ASTM D624

Hardness: measured according to ASTM D2240

Specific gravity: measured according to ASTM D792

-Vicat softening point: measured according to ASTM D1525

-For high frequency bonding and cutting, the level of PVC sheet for high frequency is set to Good, and based on this, it is classified into four stages: Excellent, Good, Fair, Poor. Indicated.

characteristic unit Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Hardness Shore a 87A 87A 89A 90 A 89A 90 A 90 A 90 A importance g / cm 3 1.19 1.10 1.145 1.124 1.05 1.077 1.15 1.13 The tensile strength kgf / ㎠ 293 304 172 170 179 202 214 201 Elongation % 802 775 659 570 655 590 645 598 Tear strength kgf / cm 92 95 74 64 79 70 85 78 Vicat Softening Point ℃ 75 82 61 58 63 60 60 61 High frequency adhesion E / G / F / P E G G G G G G G High frequency cutting E / G / F / P P P G E G E G E

As shown in Table 4, Examples 1 to 6 according to the present invention exhibited excellent physical properties compared to Comparative Examples 1 to 2, which are thermoplastic polyurethane resins having a general composition, and according to the mold shape. The cutting is easy, such as high frequency workability is shown, which can be said to be due to the synergy caused by the mixed use.

Although the present invention has been described in detail through specific examples, this is for explaining the present invention in detail, and the thermoplastic polyurethane elastomer blend composition having excellent high-frequency processability according to the present invention is not limited thereto and is within the technical spirit of the present invention. It will be apparent to those skilled in the art that modifications and variations are possible.

As described above, according to the present invention, in the case of a polyurethane elastomer obtained by polymerizing a specific polyol, a chain extender and an isocyanate, and a polyurethane elastomer blend composition using a mixture of MBS-based resins, conventional high-frequency processability of PVC level is known. It can be used in a wide range of PVC substitutes.

All simple modifications and variations of the present invention fall within the scope of the present invention, and the specific scope of protection of the present invention will be apparent from the appended claims.

Claims (10)

(a) 50 to 95% by weight of a polyurethane elastomer obtained by polymerizing an ester polyol having a number average molecular weight of 600 to 2500, a diol chain extender, and an isocyanate; And (b) 5 to 50% by weight of methacrylate / butadiene / styrene (MBS) resin; Polyurethane elastomer blend composition comprising a. The polyurethane elastomer blend composition of claim 1, wherein the polyurethane elastomer blend composition has a Shore hardness of 70A to 95A. The polyurethane elastomer blend composition of claim 1, wherein the polyurethane elastomer blend composition has a tensile strength of 220 kgf / cm 2 or less and a tear strength of 90 kgf / cm or less. The method of claim 1, wherein the ester-based polyol is poly (3-methylpentyl adipate), poly (1, 4- butylene adipate), poly (ethylene adipate), poly (ethylene- butylene adipate), From the group consisting of poly (ethylene-diethyleneglycol adipate), poly (hexylene-butylene adipate), poly (diethyleneglycol adipate), poly (1,6-hexylene adipate) and mixtures thereof Polyurethane elastomer blend composition, characterized in that selected. According to claim 1, wherein the diol chain extender 1,2-ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6 Polyurethane elastomer blend composition selected from the group consisting of -hexanediol, 1,4-cyclohexanedimethanol and mixtures thereof. The method of claim 1, wherein the isocyanate is methylene diphenyl diisocyanate, 2,4-toluene diisocyanate, naphthalene diisocyanate, xylene diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate Isophorone diisocyanate, paraphenylene diisocyanate, 3,3'-toluene-4,4'-diisocyanate, 1,6-hexamethylene diisocyanate, methylene-bis (4-cyclohexyl isocyanate) and mixtures thereof Polyurethane elastomer blend composition, characterized in that selected from the group consisting of. The polyurethane elastomer blend composition of claim 1, wherein the MBS-based resin has a core-shell structure. 8. The polyurethane elastomer blend composition of claim 7, wherein the shell portion of the core-cell structure comprises methacrylate and the core portion comprises a copolymer of styrene and butadiene. The polyurethane elastomer blend composition of claim 1, wherein the polyurethane elastomer blend composition further comprises an additive selected from the group consisting of UV stabilizers, antioxidants, lubricants, and combinations thereof. The polyurethane elastomer blend composition of claim 1, wherein the polyurethane elastomer blend composition is used for high frequency processing.

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