JPH0892344A - Thermoplastic polyurethane resin composition and molding material - Google Patents

Abstract

PURPOSE: To obtain an ether-based thermoplastic polyurethane resin suitably useful as a bag main body of an air bag device and a molded article of pad, having excellent strength, flexibility, impact resistance at ultra-low temperature to ultrahigh temperature and high durability, by making loss elastic moduli at -40 deg.C and 100 deg.C, a flow starting point and a melt viscosity at 2O0 deg.C be in specific ranges. CONSTITUTION: This thermoplastic polyurethane resin composition comprises (a) a polyether-based polymer diol, (b) 1-7mols based on the component (a) of a low-molecule diol having <=300 molecular weight and (c) an organic diisocyanate having <=300 molecular weight in an amount of the number of mols equal to the total mols of the components (a) and (b) and has 192-198 deg.C flow starting point of the reacted resin, 86-98 deg. hardness (JIS A) at a normal temperature of 23 deg.C, 2-20×10<8> dyne/cm<2> loss elastic modulus at -40 deg.C and 0.7-7×dyne/cm<2> loss elastic modulus at 100 deg.C and 0.1-25×10<5> poise melt viscosity at 200 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention has excellent strength, elongation, impact resistance from -40 ° C to 100 ° C.
The present invention relates to a thermoplastic polyurethane resin composition that can be used for an air bag device such as an air bag or an air bag pad because it has high durability.

[0002]

2. Description of the Related Art Conventionally, a thermoplastic polyurethane resin is prepared by adjusting a high molecular diol having a molecular weight of 500 or more and a low molecular diol of 300 or less by various arbitrary blending, and the number of moles substantially equal to the total number of terminal hydroxyl groups. Has been synthesized by reaction with an organic polyisocyanate of. Based on the thermoplastic polyurethane resin and the resin, alloy products such as PVC, polyester elastomer, nylon and the like, and thermoplastic resins utilize abrasion resistance superior to general-purpose resins such as polyethylene and ABS, and It is also used for various sports shoes such as shoes and women's soles.

However, the thermoplastic polyureta resin of the type described above is an alloy product with a polymer diol or a low molecular diol component having different contents or different properties, and at room temperature, hardness, tensile strength, elongation and flexural modulus. For example, various physical properties may be obtained. Especially -40 ° C
Applications with high durability in the environment of -100 ° C, for example, -40 ° C ultra-low temperature when deployed to air bag body and air bag pad material applications as air bag devices that are part of vehicle safety devices It is the current situation that we are dealing with it while conducting practical tests in the ultrahigh temperature range of 100 ° C.

[0004]

The object of the present invention is excellent in adaptability and practical durability in a wide temperature range environment range of -40 ° C. ultra low temperature to 100 ° C. ultra high temperature region suitable for the above-mentioned applications. , To obtain a thermoplastic polyurethane resin composition that can be used in an air bag and its device.

[0005]

Therefore, the present inventors have
For applications that require high durability in the ultra-low temperature range of 40 ℃ to 100 ℃, for example, in the characteristic aspect of thermoplastic polyurethane resin used for air bag which is a safety device for vehicles and molded products of air bag pad material. As a result of intensive research, a loss elastic modulus in a certain constant temperature range does not deviate from a certain specific range, and a melt viscosity at a certain constant temperature does not deviate from a certain specific range. As low as -40 ° C to 100
It was found that a thermoplastic polyurethane resin excellent in high durability in the ultrahigh temperature range of ℃ can be obtained, and the present invention has been completed.

That is, according to the present invention, the polyether high molecular weight diol (a) has a molecular weight of 1 to 7 mol based on (a) of 30.
A low molecular diol (b) of 0 or less and an organic diisocyanate (c) in a number of moles equal to the total moles of (a) and (b), and the flow starting point of the reacted resin 192-1
Hardness (JIS A) 86-9 at 98 ° C and room temperature of 23 ° C
At 8 °, the loss elastic modulus at −40 ° C. is 2 to 20 × 10 ⁸ dynes / cm ² , and the loss elastic modulus at 100 ° C. is 0.7 to 7 × 1.
A thermoplastic polyurethane resin composition, preferably a polyether polymer, having a melt viscosity at 200 ° C. of 0.1 to 25 × 10 ⁵ poises in the range of 0 ⁷ dynes / cm ^2. The diol (a) has a number average molecular weight of 10
A polytetramethylene ether diol of 00 to 10,000, preferably having a tensile strength of 100 kg / cm ² or more at a high temperature of 100 ° C. and having excellent durability characteristics particularly in a low temperature to a high temperature range. The present invention provides a thermoplastic polyurethane resin composition containing an alloy resin composition of a resin and another resin, and a molding material.

(Structure) The thermoplastic polyurethane resin composition of the present invention comprises a thermoplastic polyurethane resin obtained by reacting a polyether diol (a), a low molecular weight diol (b) and an organic diisocyanate, and the urethane resin. Alloy resin with another resin, which has a loss elastic modulus of 2 to 20 × 10 ⁸ dynes / cm ² at −40 ° C. and a loss elastic modulus of 0.7 to ⁷ × 10 ⁷ dynes / cm ² at 100 ° C. It is in the range, the flow starting point is 192 to 198 ° C., and the melt viscosity at 200 ° C. is 0.1 to 25 × 10 ⁵ poise.

The present invention does not seek the characteristics of the (a) to (c) compositions themselves used for obtaining the thermoplastic polyurethane resin, but is characterized by the loss elastic modulus range of the obtained thermoplastic polyurethane resin composition. Yes, loss elastic modulus at −40 ° C. 2 to 20 × 10 ⁸ dynes / cm ² , 0.7 to 7 at 100 ° C.
By obtaining a thermoplastic polyurethane resin composition having a loss elastic modulus in the range of × 10 ⁷ dynes / cm ² , a molding material excellent in high durability in the -40 ° C ultra-low temperature to 100 ° C ultra-high temperature range can be obtained. If it deviates from this range, it will be -40 ℃
It is inferior in durability in the ultra-high temperature range of ℃ and is not suitable for such applications such as air bag device molded products and parts.

The loss elastic modulus of the present invention means a measurement frequency with a solid viscoelasticity analyzer (Rheometric Co. product):
1 Hz, test piece: 2 mm thickness × 5 mm width × 45 mm length, measurement temperature rising rate: values at −40 ° C. and 100 ° C. measured at 4 ° C./min.

The melt viscosity of the present invention means that the melt viscosity is measured at 200 ° C. by a high-performance flow tester (measurement conditions such as nozzle 1 mm diameter × 1 mm length, load 30 kgf, heating rate 3 ° C./min). is there.

The flow starting point of the present invention is the temperature at which the resin melts and begins to flow, which is the temperature that is additionally measured when measuring the melt viscosity by the above-mentioned Koka flow tester.

According to the knowledge of the present inventors, as a thermoplastic polyurethane resin composition suitable for applications requiring high durability, for example, an air bag body or an air bag pad material, loss of the thermoplastic polyurethane resin at the temperature. The lower the elastic modulus, the poorer the heat resistance of the high temperature tensile strength in a soft feeling, the higher the loss elastic modulus at that temperature, the lower the low temperature impact resistance in a hard feeling, and the more it breaks during use. Since there is a problem, this point is necessary by selecting the resin composition of the present invention having a specific loss elastic modulus range at the above temperature. It is presumed that the secondary bonding force (burette bond, allophanate bond, etc.) of the isocyanate crosslinking system plays an important role in these physical properties.

The thermoplastic polyurethane resin composition of the present invention need only have an elastic modulus and a viscosity within the above ranges, but it has the above-mentioned characteristics and also has a hardness (JI) at room temperature of 23 ° C.
S) 86-98 °, tensile strength 250 kg / cm ² or more, breaking elongation 300% or more, tensile strength at high temperature of 100 ° C. 1
Preferably it has a 00kg / cm ² or more, particularly preferably a hardness 88 to 95 °, the tensile strength 300 kg / cm ² or more, elongation at break over 400%, and the high-temperature tensile strength 140 kg / cm ² or more of the physical properties of the 100 ° C. You can use what you have. The number average molecular weight of the thermoplastic polyurethane resin of the present invention is preferably 50,000 to 500,000, more preferably 1
It is from 0,000 to 300,000.

The polyether polymer diol (a) includes, for example, one or more alkylene oxides such as ethylene oxide, propylene oxide and tetrahydrofuran, and compounds having two or more active hydrogens, such as diols and diamines. There are products obtained by addition-polymerization of compounds such as polyethylene ether glycol, propylene ether glycol, polytetramethylene glycol, and the like. Those obtained by adding alkylene oxide to polyester diol, polysilicon diol and the like can be used. Further, ring-opening polymerization of lactones (caprolactone, valerolactone) on polytetramethylene glycol and the like are also included. A hydroxy both terminal compound of a polymer obtained by polymerizing tetrahydrofuran having a molecular weight of 1,000 to less than 10,000 is preferable, and an ether diol having a polytetramethylene chain having a molecular weight of 1,500 to 5,000 is particularly preferable.

On the other hand, the low molecular weight diol (b) is preferably a compound having a molecular weight of 300 or less and having hydroxyl groups at both ends.
The diol (b) is preferably used in an amount of 1 to 7 mol, particularly preferably 2 to 5 mol, in combination with the polymer diol (a), based on the polymer diol (a).

In order to obtain the thermoplastic polyurethane resin, the organic polyisocyanate (c) is added to (a) and (b).
Is reacted with. When obtaining the thermoplastic polyurethane resin composition of the present invention, the organic polyisocyanate (c) is
A mole number equal to the total moles of component (a) and component (b) is preferably used.

Examples of the low molecular weight diol (b) component having a molecular weight of 300 or less in the present invention include polyester diol and / or polyether diol and diol as a raw material thereof. Particularly preferred is tetramethylene glycol.

Examples of the polyester diol mentioned here include a condensation product of a polyhydric alcohol and a polybasic carboxylic acid, a condensation product of a hydroxycarboxylic acid and a polyhydric alcohol, and the like. Examples of the polyhydric alcohol used in these include ethylene glycol, propylene glycol, butanediol, diethylene glycol, 3 methylpentane glycol, glycerin, hexanetriol, trimethylolpropane, tetrameilen glycol, and the like, and polybasic carboxylic acid. For example, adipic acid,
Examples thereof include glutaric acid, azelaic acid, fumaric acid, maleic acid, phthalic acid, terephthalic acid, dimer acid, and pyromellitic acid.

As the condensate of hydroxycarboxylic acid and polyhydric alcohol, for example, castor oil, a reaction product of castor oil and ethylene glycol, propylene glycol or the like is also useful.

The polyether polymer diol (a) is
The polyether polymer diol having a number average molecular weight of 1,000 to less than 10,000 as described above may be used alone, but the polyether polymer diol may be one or two of polysilicone diol, polyethylene diol, polypropylene diol, polybutylene diol and the like. You may use together the above. The addition amount thereof is preferably 10% by weight or less, more preferably 5% by weight or less, in the polymer diol (a).

As described above, without distinguishing the magnitude of the molecular weight,
Although the components (a) and (b) are exemplified, it goes without saying that the thermoplastic polyurethane resin of the present invention can use together the polyether polymer diols (a) having different molecular weights and the low molecular diols (b) together. That is.

The organic polyisocyanate (c) used in the present invention is a compound having two or more isocyanate groups in the molecule, and various compounds generally used in the production of polyurethane resins can be used, for example, tolylene diisocyanate. , Diphenylmethane diisocyanate, dianidine diisocyanate, naphthalene diisocyanate,
Examples of aromatic polyisocyanate compounds such as triphenylmethane triisocyanate, bis (diisocyanatotolyl) phenylmethane, polymethylene polyphenyl polyisocyanate, and aliphatic polyisocyanate compounds include isophorone diisocyanate and dicyclohexymethane diisocyanate. , (Hydrogenated diphenylmethane diisocyanate), hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated tolylene diisocyanate, isopropylidene bis (cyclohexyl isocyanate), and the like.

The organic polyisocyanate (c) used in the present invention may be a combination of two or more different organic polyisocyanate compounds. In particular, an aliphatic or alicyclic polyisocyanate compound may be combined with an aromatic isocyanate compound. Good to use together.

The polyurethane resin of the present invention can be bulk-polymerized or solution-polymerized with the compounds (a) to (c) in the presence of a catalyst, if necessary, in a predetermined molar ratio, but preferably the bulk polymerization. It is a method to let.

In order to obtain the thermoplastic polyurethane resin of the present invention, 1 to 7 mol of the compound (b) is used with respect to the compound (a), and the same mol number as the total mol number of the compounds (a) and (b). The reaction is carried out using the compound (c). Usually N
The compounds (a) to (c) are used so that the molar ratio of CO / active hydrogen atom is about 1: 1. The reaction conditions at this time are not particularly limited, and any conventional conditions can be adopted.

The thermoplastic polyurethane resin thus obtained is supplied as a molding material in the form of powder, granules or pellets, and molded into an article by an extrusion molding method or an injection molding method under normal conditions.

The polyurethane resin composition of the present invention may be used at the time of or after its production, if necessary, for example, a releasing agent, a coupling agent, a colorant, a lubricant, a weather resistance, a stabilizer,
A necessary amount of additives such as a foaming agent, a rust preventive agent, an opacifying agent, a fungicide, and a filler may be added.

In the thermoplastic polyurethane resin composition of the present invention, other thermoplastic resins or elastomers such as polyvinyl chloride, ethylene-vinyl acetate copolymer, ethylene propylene-based resin may be used without departing from the object of the present invention. Elastomers such as elastomers, modified olefin elastomers, polyester elastomers, polymamide elastomers, styrene elastomers, polybutadiene elastomers, acrylic polymers such as ABS and AES, polyamides, polyimides, polyamideimides, polymers such as polyphenylene sulfide It is also possible to use together and alloy. Particularly preferably, a polyester elastomer, a polyamide, and a polyamide elastomer (nylon elastomer) are used in combination.

The amount of addition is preferably 5 to 70 parts by weight of another resin or elastomer with respect to 30 to 95 parts by weight of the thermoplastic polyurethane resin composition. More preferably, the thermoplastic polyurethane resin is 40 to 90 parts by weight, and the other resin or elastomer is 10 to 60 parts by weight.

The polyamide and the polyamide-based elastomer of the present invention may have any composition, for example, a conventionally known polyamide resin such as nylon 6, 66, 610, 11 or 12, or a polyester or polyether-based plasticizer. The above-mentioned polyamide resin, polyester, and polyether block copolyamide resin.

Here, nylon 6 is a self-polycondensation product of ε-caprolactam, nylon 66 is a polycondensation product of hexamethylenediamine and adipic acid, and nylon 610 is hexamethylenediamine. Nylon 11 is 1
It is a polycondensate of 1-aminoundecanoic acid, and nylon 12 is a self-condensate of laurolactam. In addition to them, a polycondensate of hexamethylenediamine and dodecanoic acid (nylon 612), a polycondensate of hexamethylenediamine and terephthalic acid (nylon 6T),
Polycondensation product of xylylenediamine and adipic acid (XD6
Nylon) and polycondensates of xylylenediamine and sebacic acid (XD10 nylon) can be used.

In the present invention, a copolyamide resin can also be used. The copolyamide resin may have any composition, for example nylon 6/66, 6/610, 6 /
It is a conventionally known copolymer polyamide resin such as 11, 6/12, 66/610, and 6/66/610 copolymer. The manufacturing method thereof may be any method, for example, known methods such as a method of mixing and condensing monomers and a method of mixing polymers and heating and melting to obtain a copolymer by an amide exchange reaction can be used. Various commercially available products such as Pebax (manufactured by Atchem) and UBE nylon can be used.

The polyester elastomer of the present invention is
Polyhydric alcohol and polybasic acid, those obtained from the condensate of oxycarboxylic acid, polyhydric alcohol and polybasic acid and those obtained from the condensation product of polytetramethylene ether glycol, polyhydric alcohol and polybasic acid It is obtained by ring-opening polymerization with a lactone. The above-mentioned polyhydric alcohol and polybasic carboxylic acid can be used for these. As the lactone, caprolactone, valerolactone or the like can be used. As commercially available products, Grelax EH-620, E-500
(Manufactured by Dainippon Ink and Chemicals, Inc.), Perprene (Toyobo Co., Ltd.), Hytrel (Toray DuPont Co., Ltd.) and the like.

The thermoplastic polyurethane resin composition of the present invention comprises a polyurethane resin prepared so as to have the above-mentioned specific characteristics by mechanical mixing or the like, or the above-mentioned other thermoplastic resin or other synthetic resin such as an elastomer. It goes without saying that it also includes a polyurethane resin composition of an alloy product prepared by mixing and modifying so as to have the above-mentioned specific properties.

The resin composition of the present invention is used as a molding material, and is used for molded articles which require high durability in the range of -40 ° C ultra-low temperature to 100 ° C ultra-high temperature. As the molded product, injection molding method, extrusion molding method, film for air bag main body obtained by blow molding method, suitable for use as a sheet and air bag pad material, soccer shoe sole, baseball shoe sole,
It is used for applications requiring high durability, such as tire anti-skid devices, and applications such as conveyor belts, hoses, tubes, watch bands, heel tops, gears and casters.

[0036]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In addition, the part in an example shall mean a weight part.

(Example 1) 2000 parts of polytetramethylene ether diol having an average molecular weight of 2000 obtained from tetrahydrofuran, tetramethylene glycol 287
Part, and 1065 parts of diphenylmethane-4,4′-diisocyanate, in the same manner as in Example 1 to produce a sample of thermoplastic polyurethane resin elastomer A.

Example 2 1425 parts of a polyol having an average molecular weight of 1500 obtained from tetrahydrofuran, 75 parts of a carbinol-modified silicone diol having an average content of 13500, 330 parts of tetramethylene glycol, and 1 part of diphenylmethane-4,4'-diisocyanate.
A sample of the thermoplastic polyurethane resin elastomer B was produced from 177 parts in the same manner as in Example 1.

Comparative Example 1 A thermoplastic polyurethane resin was prepared in the same manner as in Example 1 except that 2000 parts of a polyol having an average molecular weight of 1000 obtained from tetrahydrofuran, 222 parts of tetramethylene glycol, and 885 parts of diphenylmethane-4.4'-diisocyanate were used. A sample of Elastomer C was prepared.

(Example 3) 90 parts of the urethane elastomer A obtained in Example 1, 6-66 copolymer nylon (U
A blend of 10 parts of BE nylon 5013B and Ube Industries Ltd. was kneaded at 200 to 210 ° C. and pelletized to produce a sample of a thermoplastic polyurethane resin composition D.

Example 4 A mixture of 80 parts of the urethane elastomer A obtained in Example 1 and 20 parts of a polyester elastomer (Grelax EH-620) was added in the same manner as in Example 3 to obtain a thermoplastic resin. A sample of polyurethane resin composition E was prepared.

(Example 5) A thermoplastic polyurethane resin composition was prepared in the same manner as in Example 3 except that the urethane elastomer B obtained in Example 2 was blended in an amount of 70 parts by weight and 30 parts by weight of nylon elastomer (Pepax NX1508). F
Samples were manufactured.

(Example 6) The thermoplastic elastomer obtained by mixing 40 parts of the urethane elastomer C obtained in Comparative Example 1 and 60 parts of the polyester elastomer (Grelax EH-620) in the same manner as in Example 3 was used. A sample of polyurethane resin composition G was prepared.

Comparative Example 2 70 parts of the urethane elastomer B obtained in Example 2 was mixed with 6-66 copolymer nylon (U
A sample of a thermoplastic polyurethane resin composition H was produced in the same manner as in Example 3 except that the blended amount of BE nylon 5013B) was 30 parts.

(Comparative Example 3) A thermoplastic polyurethane resin was prepared in the same manner as in Example 3, except that the urethane elastomer A obtained in Example 1 was blended in an amount of 50 parts by weight and 50 parts by weight of nylon elastomer (Pebax MX-1508). A sample of Composition I was prepared.

Comparative Example 4 A thermoplastic polyurethane was prepared in the same manner as in Example 3, except that 30 parts of the urethane elastomer A obtained in Example 1 and 70 parts of a polyester elastomer (Greak EH-620) were blended. A sample of resin composition J was manufactured.

Test pieces were prepared from the thermoplastic polyurethane resin compositions of Examples 1 to 6 and Comparative Examples 1 to 4 by thermoforming such as injection and extrusion. JIS K-7311, method, AST
Measurement of various physical properties according to the MD-790 method, solid viscoelasticity analyzer (frequency 1 Hz, test piece 2 mm thickness,
Loss modulus measurement by temperature rise rate 4 ° C / min etc. measurement condition and melt viscosity measurement result by Koka type flow tester (nozzle 1 mm diameter x 1 mm length, load 30 kgf, temperature rise rate 3 ° C / min etc. measurement condition) Are shown in Tables 1 and 2.

Tables 1 and 2 show the results of 100 ° C. high temperature tensile strength measurement and −40 ° C. low temperature tensile strength measurement according to JIS K-7311, by making a test piece from each of the above-mentioned samples by injection molding. .

Each of the above samples is extruded (T-die, inflation, blow molding, etc.) or calendered to make an air bag from a 100-500 μm thick film or sheet, and then injection-molded. An air bag pad molded product having a thickness of 1 to 7 mm was prepared and incorporated as an air bag device, and the feel and inflation expansion practical test results in a low to high temperature range of -40 ° C to 100 ° C are shown in Tables 1 and 2.

[0050]

[Table 1] Table 1

[0051]

[Table 2] Table 1 (continued)

[0052]

[Table 3] Table 1 (continued)

[0053]

[Table 4] Table 2

[Evaluation of Deployment Practical Test] ○: No problem at deployment, Δ: Some problem at deployment, but acceptable for practical use, ×: Problem at deployment

[0055]

EFFECT OF THE INVENTION The resin composition of the present invention is an ether type thermoplastic polyurethane resin, and the loss elastic modulus at -40 ° C and 100 ° C, the flow starting point and the melt viscosity at 200 ° C are within a specific range. , -40 ℃ ultra-low temperature ~ 100 ℃ ultra-high temperature range, because it has excellent durability, such as strength, flexibility, impact resistance,
It is preferably used for a bag body of an air bag device, a pad molded product, and the like that require high durability in an ultra-low temperature to ultra-high temperature range. Suitable for air bag equipment.

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Claims (6)

[Claims] 1. A polyether polymer diol (a),
A low molecular weight diol (b) having a molecular weight of 300 or less of 1 to 7 moles with respect to (a) and an organic diisocyanate (c) in a mole number equal to the total moles of (a) and (b) were reacted. Resin flow start point 192-198 ° C., 23
Hardness (JIS A) 86-98 ° at room temperature of -40, -40
Loss modulus at ℃ 2 to 20 × 10 ⁸ dynes / cm ² , 10
The loss elastic modulus at 0 ° C. is in the range of 0.7 to ⁷ × 10 ⁷ dynes / cm ² , and the melt viscosity at 200 ° C. is 0.1 to 2
A thermoplastic polyurethane resin composition, characterized in that it is 5 × 10 ⁵ poise. 2. A polyether-based polymer diol (a)
Is a polytetramethylene ether-based diol having a number average molecular weight of 1,000 to 10,000, and the thermoplastic polyurethane resin composition according to claim 1. 3. Tensile strength 250 kg / at room temperature of 23 ° C.
The thermoplastic polyurethane resin composition according to claim 1, which has physical properties of cm ² or more and elongation at break of 300% or more and has a tensile strength at 100 ° C. of 100 kg / cm ² or more. 4. The thermoplastic polyurethane resin composition according to claim 1, wherein the low molecular weight diol (c) is polytetramethylene glycol. 5. A polyamide elastomer and / or
Alternatively, the thermoplastic polyurethane resin composition according to claim 1, which contains a polyester elastomer. 6. A molding material obtained from the thermoplastic polyurethane resin composition according to claim 1.