JP2000212430A - Low-hardness thermoplastic polyurethane resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition exhibiting low hardness and excellent in moldability and mechanical characteristics by admixing a specific amount of diisononyl phthalate with a thermoplastic polyurethane resin. SOLUTION: This composition comprises 5-80 pts.wt., based on 100 pts.wt. of a thermoplastic polyurethane resin (hereinafter described as TPU), of diisononyl phthalate (hereinafter described as DINP). As the TPU can be employed anyone usually used. These TPUs are mainly composed of a polymer diol, a chain extender and a polyisocyanate. DINP is preferable from the viewpoint of compatibility with the TPU, mechanical properties, processability, costs, safety and the like. This composition is obtained by mixing the TPU with DINP. Mixing can be carried out using any conventional method; soaking of a flaky TPU with DINP, previous mixing of DINP with a raw material for TPU, simultaneous addition of DINP in one shot preparation of a TPU or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermoplastic polyurethane resin composition characterized by low hardness and excellent mechanical properties.

[0002]

2. Description of the Related Art Conventionally, as a method for obtaining a low-hardness thermoplastic polyurethane resin (hereinafter abbreviated as TPU), a hard segment comprising a chain extender and an isocyanate component is compounded in a compounding aspect with a small amount, and a crystal is obtained in a raw material side. For the purpose of breaking down the reaction, a method of using a polyol having a large molecular weight or a raw material having a side chain structure has been adopted. Meanwhile, general-purpose plasticizers such as 2-ethylhexyl phthalate, butylbenzyl phthalate, and di-phthalate as plasticizer-added TPUs.
A method of blending n-butyl and the like has also been adopted.

[0003]

However, in the conventional method of lowering the hardness of the TPU itself, the reaction hardening in the synthesis stage is slow, and it has been difficult to efficiently manufacture the TPU due to its tackiness and low melting point characteristics. Further, even if it can be manufactured, there are problems in molding such as adhesion between products during molding and adhesion to a mold, and shapeability due to slow hardness development.
In addition, plasticizer-added TPU cannot contain a large amount of plasticizer in terms of compatibility, and recently, these plasticizers have been taken up by chemical substances suspected of having an endocrine disrupting effect. Therefore, a change to a desirable composition is required.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in order to improve such conventional problems, and as a result, diisononyl phthalate (hereinafter abbreviated as DINP) has been added to a general-purpose TPU.
, A TPU composition characterized by low hardness and excellent moldability and mechanical properties was found, and the present invention was completed.

That is, according to the present invention, diisononyl phthalate is added in an amount of 5 to 80 parts by weight to 100 parts by weight of a thermoplastic polyurethane resin.
The addition of parts by weight provides a thermoplastic polyurethane resin composition characterized by low hardness and excellent mechanical properties.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As a TPU of the present invention, all commonly used TPUs are used. These TPUs are mainly composed of a polymer diol, a chain extender and a polyisocyanate. The high molecular weight diol used in the TPU of the present invention includes a hydroxyl group-terminated molecular weight of 400 to 100 which is usually used as a reaction partner of polyisocyanate.
00 polyethers, polyesters, polyesteramides, polyetheresters, polycarbonates and the like. Examples of polyethers include, for example, polymerization products such as tetrahydrofuran, propylene oxide, and ethylene oxide, copolymerization products thereof, and graft polymers of polyether with vinyl monomers. Examples of the polyesters and polyesteramides include those obtained by a condensation reaction from a polyhydric alcohol and a polycarboxylic acid, optionally using a diamine or an amino alcohol in combination. Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 2-methylpropanediol, neopentyl glycol, and 3-methyl- Examples include 1,5-pentanediol, 2-methyloctanediol, 1,9 nonanediol, and 1,4-cyclohexanedimethanol. As polyvalent carboxylic acids, for example, succinic acid, adipic acid, sebacic acid, dimer acid,
Examples include hydrogenated dimer acid, phthalic acid, alkyl phthalates, maleic acid, fumaric acid, and itaconic acid.
Further, those obtained by ring-opening polymerization of cyclic esters such as butyrolactone, valerolactone, and caprolactone are also included. Examples of the polyetheresters include those obtained in the same manner as polyesters except that polyethers are used for part or all of the polyhydric alcohols used in the condensation reaction for obtaining the polyesters. As polycarbonates, 1,6-
Examples thereof include those obtained by transesterification of a diol such as hexanediol or 1,4-cyclohexanedimethanol with a cyclic carbonate such as dialkyl carbonate, diaryl carbonate or ethylene carbonate.

The chain extender used in the present invention includes ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, bis-β-hydroxy Compounds having a molecular weight of less than 400, such as ethoxybenzene, 3-methyl-1,5-pentanediol, neopentyl glycol, N-phenyldiisopropanolamine, and monoethanolamine. These compounds can be used alone or in a mixture of two or more.

The polyisocyanate used in the present invention includes phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, naphthylene diisocyanate, diphenylmethane diisocyanate, and aromatic diisocyanates comprising isomers thereof. 6
Aliphatic diisocyanates such as hexamethylene diisocyanate, 1,12-dodecane diisocyanate, trimethyl-hexamethylene diisocyanate, cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, hydrogenated xylylene diisocyanate, alicyclic diisocyanates such as norbornane-diisocyanate methyl, etc. Can be mentioned. Further, an isocyanate group-terminated compound obtained by the reaction of these compounds with an active hydrogen group-containing compound, or a modified polyisocyanate obtained by the reaction of these compounds, for example, a carbodiimidization reaction, etc., can also be mentioned. Also, methanol, n-butanol,
Polyisocyanates partially stabilized with a blocking agent having one active hydrogen in the molecule, such as benzyl alcohol, ethyl acetoacetate, ε-caprolactam, methyl ethyl ketone oxime, phenol and cresol, can also be mentioned.

In producing the TPU of the present invention,
A catalyst can be added as needed. Catalysts that can be used include, for example, triethylamine, triethylenediamine, N-methylimidazole, N-ethylmorpholine,
1,8-diazabicyclo-5,4,0-undecene-7
Amines such as (DBU); organic metals such as potassium acetate, stannasoctoate and dibutyltin dilaurate; and phosphorus-based compounds such as tributylphosphine, phosphorene and phosphorene oxide.

The TPU of the present invention comprises three components of a polymer diol, a chain extender and a polyisocyanate, and a ratio (R) of the number of moles of isocyanate groups of the polyisocyanate to the total number of moles of active hydrogen groups of the polymer diol and the chain extender. Value) is adjusted to 0.7 to 1.3, preferably 0.9 to 1.05. The chain extender and the polymer diol are preferably blended such that the ratio (R ′ value) of the mole number of the active hydrogen group of the chain extender to the mole number of the active hydrogen group of the polymer diol is 0.1 to 15. .

DINP used in the present invention is an ester compound of phthalic acids such as phthalic anhydride and alkyl phthalate and isononyl alcohol. DINP
Is preferred in terms of compatibility with TPU, mechanical properties, workability, price, safety, etc. <5 to 8 parts by weight of TPU
It is desirably contained in an amount of 0 parts by weight, preferably 10 to 50 parts by weight. If the DINP is less than 5 parts by weight based on 100 parts by weight of the TPU, the characteristics of DINP cannot be exhibited, which is not preferable. If it exceeds 80 parts by weight, the compatibility and mechanical properties are deteriorated.

The TPU composition of the present invention comprises TPU and DIN
Obtained by mixing P. As the mixing method, all the usual mixing methods can be used. For example, the flake TPU has
Method of impregnating INP, DINP to TPU in molten state
, A method of previously mixing DINP with a TPU raw material to obtain a TPU composition, and a method of simultaneously adding DINP at the time of one-shot production of TPU. The TPU composition obtained by such a composition varies depending on the hardness of the base TPU, but is 75 A (JIS-K7311).
The following low hardness products are possible. Further, the molded product processed with the TPU composition of the present invention has a transparent appearance.

For the production of the TPU of the present invention, a known TPU is used.
Production methods, for example, one-shot method, prepolymer method, batch reaction method, continuous reaction method, kneader method,
A method such as a method using an extruder can be adopted. For example, in a method using a kneader, a polymer diol and 1,4-butanediol are charged into a kneader, heated to 80 ° C., charged with polyisocyanate, reacted for 10 to 60 minutes, and cooled to form a powder or block. TPU can be produced. Further, the TPU composition can be obtained by heating and impregnating these powdery or block-like TPUs by mixing DINP with a Henschel mixer. This impregnated material is formed into pellets by an extruder or the like as necessary. As a device used for the production of TPU, a kneader connected with a multi-component measuring mixer, a single-screw or multi-screw extruder, or the like can be used.

The TPU composition obtained according to the present invention comprises:
Other resins can be added as needed. Resin that can be used, for example, ABS resin, SAN resin, vinyl chloride resin, polypropylene, polyethylene, polystyrene, polyacetal, polyamide, polyester, polyester ether, polycarbonate, epoxy resin,
An amino resin, a phenol resin, a silicone resin, a fluorine resin, and the like. These resins can be added in an amount of 1 to 100 parts by weight based on 100 parts by weight of the TPU composition of the present invention. The TPU composition obtained according to the present invention may contain other substances as necessary. Substances that can be added include, for example, antioxidants, ultraviolet absorbers, heat resistance improvers, plasticizers, lubricants, antistatic agents, conductivity-imparting agents, coloring agents,
Inorganic and organic fillers, fibrous reinforcing materials, hydrolysis inhibitors, reaction retarders and the like.

The TPU composition of the present invention can be applied to a generally used TPU molding method and molding conditions. For example, there are molding methods such as extrusion molding, injection molding, blow molding, calendar processing, roll processing, press processing, centrifugal molding, and rotational molding.

[0015]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In Examples and Comparative Examples,
All "parts" mean "parts by weight".

Example 1 In a reaction vessel equipped with a stirrer, 100 parts of an ether-based diol (PTG1000 manufactured by Hodogaya Chemical Co., Ltd., hydroxyl value 112: KOH mg / g) as a polymer diol, and 1,4-butane as a chain extender 8.1 parts of diol (1,4-BG),
0.79 parts of Irganox 1010 and 0.4 parts of Tinuvin P were added and mixed uniformly, adjusted to 100 ° C. and 4,4 ′.
-Diphenylmethane diisocyanate (MDI)
0.4 part was added, and a urethanization reaction was performed. 90 reactants
When the temperature reached ° C, it was poured on a bat and solidified. The obtained solid was aged in an electric furnace at 80 ° C. for 24 hours, and after cooling, the solid was pulverized to obtain T as a base resin of the present invention.
155 parts of PU were obtained. To 100 parts of this TPU, 20 parts of diisononyl phthalate (DINP) was stirred and mixed with a Henschel mixer, and when the DINP became impregnated with heat, it was passed through an extruder and formed into pellets to form the TMP of the invention.
A PU composition was obtained. The obtained pellets were molded using an injection molding machine at a molding temperature of 150 to 190 ° C. and a molding pressure of 600 kg.
A sheet of 110 × 55 × 2 mm was formed under the condition of f / cm ² , and the releasability from the mold was confirmed. In addition, after the sheet was annealed at 80 ° C. for 16 hours, the bleeding state and transparency of the plasticizer were observed and a tensile test (JIS-K7311) was performed.
The results are shown in Table 1.

Example 2 The procedure of Example 1 was repeated except that the amount of DINP was changed to 35 parts per 100 parts of TPU. Table 1 shows the test results.

Comparative Example 1 In a reaction vessel equipped with a stirrer, 100 parts of an ether diol (PTG1000 manufactured by Hodogaya Chemical Co., Ltd., hydroxyl value 112: KOH mg / g) as a polymer diol, and 1,4-butane as a chain extender were added. 5.5 parts of diol (1,4-BG),
0.72 parts of Irganox 1010 and 0.36 parts of Tinuvin P were added and mixed uniformly.
40.7 parts of 4'-diphenylmethane diisocyanate (MDI) was added, and a urethanization reaction was performed. 9 reactants
When the temperature reached 0 ° C., the mixture was poured onto a vat and solidified.
The obtained solid was aged in an electric furnace at 80 ° C. for 24 hours,
After cooling, the solid was pulverized to obtain 140 parts of TPU. The obtained TPU was passed through an extruder and pelletized to obtain an unplasticized TPU. The obtained pellets were evaluated in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 2 The procedure of Example 1 was repeated, except that DINP was changed to di-2-ethylhexyl phthalate (DOP). Table 1 shows the test results.

[0021]

[Table 1]

[0022]

As described above, according to the present invention, it has become possible to provide a TPU composition having low hardness and excellent mechanical properties.

The TPU composition obtained according to the present invention comprises:
For example, tube hoses such as high pressure hoses, medical tubes, oil / pneumatic tubes, watering tubes, fire hoses, air mats, diaphragms, keyboard sheets,
Films such as synthetic leather, life jackets and wet suits, power and communication cables, computer wiring, automobile wiring, electric wires and cables such as various curl cords,
Various ropes, various drive belts, various transport belts,
Various types of extruded molded products such as various food conveying belts, slip stoppers, and injection molding related products, such as ball joints, dust covers, pedal stoppers, door lock strikers, bushes, spring covers, bearings, anti-vibration parts,
Such as automotive parts, various gears, seals and packings, connectors, rubber screens, mechanical parts such as printing drums, soles and points for sports shoes, shoe-related parts such as women's shoes top lifts, rollers, casters,
It can also be used effectively for grips, snow chains, etc.

Claims (1)

[Claims] 1. A thermoplastic polyurethane resin composition characterized by low hardness and excellent mechanical properties by adding 5-80 parts by weight of diisononyl phthalate to 100 parts by weight of a thermoplastic polyurethane resin.