JPH0925407A - Thermoplastic polyurethane composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject non-adhesive composition excellent in blocking resistance and mold release characteristics and capable of giving a forming such as a film and a sheet having excellent softness, elastic recovery and mechanical properties. SOLUTION: This composition is obtained by compounding 50-90wt.% of a thermoplastic polyurethane A, 10-40wt.% of a thermoplastic polyurethane B and 5-30wt.% of an aromatic vinyl compound-conjugated diene block copolymer C. The thermoplastic polyurethane A has a number average molecular weight of 2000-8000, it is obtained by reacting a polyester diol consisting of 3-methyl-1,5-pentanediol unit of >=30mol.% based on a diol unit with an organic diisocyanate and a chain extender, and it contains nitrogen atoms in a weight ratio of <=2.5%. The thermoplastic polyurethane B is obtained by reacting a polyester diol having a number average molecular weight of 1500-4000 with an aromatic diisocyanate and a chain extender, and it contains nitrogen atoms in a weight ratio of >=3.5%. Optionally, a higher fatty acid bisamide is compounded in an amount of 0.3-5wt.% based on the total weight of the components A to C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic polyurethane composition comprising a low-hardness thermoplastic polyurethane, a high-hardness thermoplastic polyurethane and a block copolymer, and a molded article such as a film or sheet made of the same. The thermoplastic polyurethane composition of the present invention is non-adhesive, has excellent blocking resistance and release property, and when formed into a film, sheet, etc., can be smoothly wound up without using release paper. In addition, these rolled-up molded articles can be smoothly rewound without causing blocking. Molded products such as films and sheets obtained from the thermoplastic polyurethane composition of the present invention are also excellent in elastic recovery, flexibility and mechanical properties, and the films and sheets are particularly useful as stretchable films and sheets. .

[0002]

2. Description of the Related Art Since thermoplastic polyurethane has many characteristics such as excellent elasticity, abrasion resistance and oil resistance, it has been attracting attention as a substitute material for rubber and plastic, and ordinary plastic molding processing methods can be applied. Used as a molding material in a wide range of applications. However, in particular, low-hardness thermoplastic polyurethane has strong adhesiveness and is apt to cause blocking, so that it is difficult to wind the film or sheet alone when it is produced by extrusion molding or the like. That is, when wound alone, it is difficult to rewind the film or sheet,
The current situation is that it becomes impossible and cannot be used. Therefore, for the purpose of detackifying, preventing blocking, imparting releasability, etc., a method of adding a lubricant to the thermoplastic polyurethane, a method of blending another polymer with the thermoplastic polyurethane, a film or sheet of the thermoplastic polyurethane is used. A method of forming a film on a release paper containing silicone or a release paper laminated with polyethylene or polypropylene and winding the release film together with the release paper is used.

[0003]

However, in the case of the above-mentioned method, it is necessary to use a large amount of lubricant in order to exert the antiblocking effect and the releasing effect, and as a result, the lubricant is applied to the surface of the product. Have bleeding out, resulting in fog on the film or sheet surface and poor smoothness. In addition, when adhesion is required during the secondary processing, insufficient adhesion may occur, which is not preferable. In the case of the above method,
Since it is necessary to blend a large amount of polymer in order to obtain anti-blocking properties, the inherent properties of thermoplastic polyurethane are apt to be lost, and further, the surface of a film or sheet is roughened, resulting in poor appearance. Further, in the case of the above-mentioned method, it is necessary to use a release paper or the like, which requires time and effort for molding, and since expensive release paper or the like is used, there is a drawback that the cost becomes high.

The object of the present invention is not to lose the excellent properties inherent to thermoplastic polyurethanes, in particular the flexibility, elastic recovery and mechanical properties, but also to use a large amount of lubricants, polymers and expensive release papers. Provide a thermoplastic polyurethane composition capable of effectively producing a molded article such as a thermoplastic polyurethane film or sheet excellent in appearance and physical properties by effectively preventing adhesion and blocking without using It is to be. Another object of the present invention is to provide a molded article such as a film or sheet made of the above-mentioned thermoplastic polyurethane composition.

[0005]

Means for Solving the Problems As a result of repeated studies by the present inventors to achieve the above object, as a result, a thermoplastic polyurethane of a specific high hardness and an aromatic polyurethane of a specific high hardness are obtained. When a vinyl compound-conjugated diene block copolymer is blended in a specific ratio, the thermoplastic polyurethane composition has excellent properties inherent in a low-hardness thermoplastic polyurethane, and is also excellent in non-adhesiveness, blocking resistance and releasability. When a molded product such as a film or a sheet is produced using this thermoplastic polyurethane composition, it is possible to wind, rewind, and mold without using a release paper or a release agent. Can be smoothly and easily removed, and the obtained film or sheet has excellent flexibility, elastic recovery and mechanical properties. Or it was useful as a sheet. Further, the present inventors further improve the non-adhesiveness, the blocking resistance, and the releasability by further blending the higher fatty acid bisamide in the thermoplastic polyurethane composition in a specific ratio. The present invention has been completed based on the findings and these findings.

That is, the present invention has a number average molecular weight of 20.
It is from 0 to 8000, and the nitrogen atom content is 2., which is obtained by reacting a polyester diol in which 30 mol% or more of diol units are 3-methyl-1,5-pentanediol units, an organic diisocyanate, and a chain extender. 5
Weight% or less of thermoplastic polyurethane (A); obtained by reacting a polyester diol having a number average molecular weight of 1500 to 4000, an organic diisocyanate and a chain extender, the nitrogen atom content is 3.5% by weight or more, and the logarithmic viscosity is It is 0.9 dl / g or less, and the differential scanning calorimetry (DS
C) has an endothermic peak in the range of 200 to 220 ° C. and has a crystallization enthalpy (ΔH) of 2 to 15 J / g, which is determined from the endothermic peak, and a thermoplastic polyurethane (B); and an aromatic vinyl compound-conjugated diene A thermoplastic polyurethane composition comprising a block copolymer (C), comprising:
Based on the total weight of (A) to (C), the thermoplastic polyurethane (A) is 50 to 90% by weight, the thermoplastic polyurethane (B) is 10 to 40% by weight, and the aromatic vinyl compound-conjugated diene block copolymer weight. 5-30% by weight of coalescence (C)
The thermoplastic polyurethane composition is characterized in that it is contained at a ratio of. Then, the present invention is based on the total weight of the thermoplastic polyurethane (A), the thermoplastic polyurethane (B) and the aromatic vinyl compound-conjugated diene block copolymer (C), and further higher fatty acid bisamide (D).
Is the thermoplastic polyurethane composition containing 0.3 to 5% by weight. Further, the present invention is a molded article such as a film or sheet made of the above thermoplastic polyurethane composition.

Polyester diol [hereinafter referred to as polyester diol (A)] used in the production of thermoplastic polyurethane (A) and polyester diol [hereinafter referred to as polyester diol (B)] used in the production of thermoplastic polyurethane (B). ) Is composed essentially of diol units and dicarboxylic acid units.

The content of the 3-methyl-1,5-pentanediol unit in the diol unit constituting the polyester diol (A) is required to be 30 mol% or more, and 50 mol% or more. preferable. When the content of the 3-methyl-1,5-pentanediol unit is less than 30 mol%, the crystallinity of the polyester diol (A) becomes large, so that the thermoplastic polyurethane (A) obtained has flexibility and cold resistance. Inferior in elasticity and elastic recovery.

If the diol unit constituting the polyester diol (A) is 70 mol% or less, 3-
Diol units other than methyl-1,5-pentanediol units can be included. For example, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,7-heptanediol, 1,8 Derived from aliphatic diols such as -octanediol, 1,9-nonanediol, 1,10-decanediol and 2-methyl-1,8-octanediol; cycloaliphatic diols such as cyclohexanedimethanol and cyclohexanediol A unit can be mentioned, and these can be contained 1 type or 2 types or more.

Examples of the dicarboxylic acid unit constituting the polyester diol (A) include saturated aliphatic dicarboxylic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid; and saturated such as cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acid; phthalic acid,
Examples thereof include units derived from aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and one or more of these can be included.

Examples of the diol unit constituting the polyester diol (B) include ethylene glycol, propylene glycol, 1,3-propanediol, 1,
4-butanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 1,
7-heptanediol, 1,8-octanediol,
1,9-nonanediol, 1,10-decanediol,
3-methyl-1,5-pentanediol, 2-methyl-
Examples thereof include aliphatic diols such as 1,8-octanediol; units derived from alicyclic diols such as cyclohexanedimethanol and cyclohexanediol, and one or more of these can be contained.

Examples of the dicarboxylic acid unit constituting the polyester diol (B) include saturated aliphatic dicarboxylic acids such as glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid and sebacic acid; saturated such as cyclohexanedicarboxylic acid. Alicyclic dicarboxylic acid; phthalic acid,
Examples thereof include units derived from aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, and one or more of these can be included. Among these, it is preferable to include a unit derived from a saturated aliphatic dicarboxylic acid because the flexibility and elastic recovery are good.

The number average molecular weight of the polyester diol (A) is 2000 to 8000, and 3000 to 6000.
It is preferred that When the number average molecular weight is less than 2000, it is not possible to obtain a low hardness thermoplastic polyurethane (A) having excellent properties such as elastic recovery and flexibility.
On the other hand, when the number average molecular weight exceeds 8000, not only the productivity of the thermoplastic polyurethane (A) is lowered, but also the extrusion moldability of the obtained thermoplastic polyurethane composition becomes poor.

The polyesterdiol (B) has a number average molecular weight of 1500 to 4000 and 2000 to 3500.
It is preferred that When the number average molecular weight is less than 1500, the blocking resistance of the resulting thermoplastic polyurethane composition is lowered. The number average molecular weight is 4000
When it exceeds the above range, the fluidity of the thermoplastic polyurethane (B) is lowered, and the dispersibility in the thermoplastic polyurethane (A) is poor, so that the extrusion moldability of the resulting thermoplastic polyurethane composition becomes poor. The number average molecular weights of the polyester diols referred to in this specification are all JIS K.
It is the number average molecular weight calculated based on the hydroxyl value measured according to 1577.

Polyester diols (A) and (B)
Is produced by polycondensing the above-mentioned dicarboxylic acid component and diol component by a conventionally known transesterification reaction, direct esterification reaction, or the like. In that case, the polycondensation reaction can be carried out in the presence of a titanium-based or tin-based polycondensation catalyst, but when a titanium-based polycondensation catalyst is used, it is contained in the polyester diol after completion of the polycondensation reaction. It is preferable to deactivate the titanium-based polycondensation catalyst.

Polyester diols (A) and (B)
When a titanium-based polycondensation catalyst is used in the production of the above, any of the titanium-based polycondensation catalysts conventionally used in the production of polyester diols can be used, and there is no particular limitation, but examples of preferred titanium-based polycondensation catalysts Examples thereof include titanic acid, tetraalkoxytitanium compounds, titanium acylate compounds, and titanium chelate compounds. More specifically, tetraisopropyl titanate, tetra-n-butyl titanate, tetra-2
-Ethylhexyl titanate, tetraalkoxy titanium compounds such as tetrastearyl titanate, polyhydroxy titanium stearate, titanium acylate compounds such as polyisopropoxy titanium stearate, titanium acetyl acetate, triethanolamine titanate, titanium ammonium lactate, titanium ethyl lactate, Mention may be made of titanium chelate compounds such as titanium octylene glycolate.

The amount of the titanium-based polycondensation catalyst used is not particularly limited, but is generally about 0.1 to 50 ppm with respect to the total weight of the reaction components for forming the polyester diol.
Is preferred and about 1 to 30 ppm is more preferred.

Examples of the method for deactivating the titanium polycondensation catalyst contained in the polyester diol include, for example, a method in which the polyester diol obtained after the completion of the esterification reaction is brought into contact with water under heating to deactivate it. Examples thereof include a method of treating phosphoric acid, a phosphoric acid ester, a phosphorous acid, and a phosphorous compound such as phosphorous acid ester. When the titanium-based polycondensation catalyst is contacted with water to deactivate it, water is added to the polyester diol obtained by the esterification reaction in an amount of 1% by weight or more to obtain 70-150.
C., preferably 90 to 130.degree. C. for 1 to 3 hours. The deactivation treatment of the titanium-based polycondensation catalyst may be performed under normal pressure or under pressure. It is desirable to depressurize the system after deactivating the titanium-based polycondensation catalyst, since water used for deactivation can be removed.

Thermoplastic polyurethanes (A) and (B)
The type of organic diisocyanate used in the production of the above is not particularly limited, and any of the organic diisocyanates conventionally used in the production of ordinary polyurethane can be used, and those having a molecular weight of 500 or less are preferable. Examples of organic diisocyanates include, for example, 4,4′-diphenylmethane diisocyanate, p-phenylene diisocyanate, toluylene diisocyanate, 1,5-naphthylene diisocyanate, 3,3′-dichloro-4,
Aromatic diisocyanates such as 4′-diphenylmethane diisocyanate and xylylene diisocyanate,
Aliphatic or alicyclic diisocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate and hydrogenated xylylene diisocyanate can be mentioned. One or more of these organic diisocyanates are used. Among these, 4,
Preference is given to using 4'-diphenylmethane diisocyanate. In addition, a tri- or higher functional polyisocyanate such as triphenylmethane triisocyanate can be used in a small amount as necessary.

Thermoplastic polyurethanes (A) and (B)
As the chain extender used in the production of the above, any of those conventionally used in the production of ordinary polyurethane can be used, and it is not particularly limited, but it has two or more active hydrogen atoms capable of reacting with an isocyanate group in the molecule. Having, molecular weight 30
It is preferable to use a low molecular weight compound of 0 or less. For example, ethylene glycol, 1,2-propanediol,
1,4-butanediol, 1,5-pentanediol,
1,6-hexanediol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-cyclohexanediol, bis (β-hydroxyethyl) terephthalate,
Diols such as xylylene glycol, hydrazine, ethylenediamine, propylenediamine, xylylenediamine, isophoronediamine, piperazine, piperazine derivatives, phenylenediamine, tolylenediamine,
Examples thereof include diamines such as xylylenediamine, adipic acid dihydrazide and isophthalic acid dihydrazide, amino alcohols such as aminoethyl alcohol and aminopropyl alcohol, and one or more of them are used. Among these, it is preferable to use 1,4-butanediol in terms of flexibility, elastic recovery and mechanical properties.

Thermoplastic polyurethanes (A) and (B)
In the production of, the organic diisocyanate is preferably used in an amount such that the isocyanate group equivalent is 0.98 to 1.10 per equivalent hydrogen atom in the polyester diol and the chain extender. By using the polyester diol, the chain extender and the organic diisocyanate in the above proportions, a thermoplastic polyurethane composition excellent in flexibility, elastic recovery, mechanical properties and moldability can be obtained, which is preferable.

In producing a thermoplastic polyurethane using the above polyester diol, organic diisocyanate, and chain extender, a tin-based urethane-forming catalyst having catalytic activity for the urethane-forming reaction can be used. When a tin-based urethane-forming catalyst is used, the molecular weight of the thermoplastic polyurethane increases rapidly, and since the molecular weight of the thermoplastic polyurethane is maintained at a sufficiently high level even after molding, a thermoplastic polyurethane with better physical properties can be obtained. can get. As the tin-based urethane-forming catalyst, for example,
Examples thereof include dialkyltin diacylate such as dibutyltin diacetate and dibutyltin dilaurate, and dialkyltin bismercaptocarboxylic acid ester salt such as dibutyltin bis (3-mercaptopropionic acid ethoxybutyl ester) salt. The amount of these tin-based urethane-forming catalysts used is, in terms of tin atoms, 0.5 to 15 ppm with respect to polyurethane (that is, the total weight of reactive raw material compounds such as polyester diol, organic diisocyanate, and chain extender). Is preferred.

Thermoplastic polyurethanes (A) and (B)
The production method of is not particularly limited, and a known urethanization reaction technique such as a prepolymer method or a one-shot method is adopted using the above polyester diol (A) or (B), an organic diisocyanate and a chain extender. be able to. When producing the thermoplastic polyurethane (A),
Among these, it is preferable to employ the method of melt polymerization in the substantial absence of a solvent, and it is particularly preferable to employ the continuous melt polymerization method using a multi-screw extruder. Further, in the case of producing the thermoplastic polyurethane (B), it is preferable to adopt a belt method by the prepolymer method because it is easy to obtain a thermoplastic polyurethane composition having excellent blocking resistance.

Thermoplastic polyurethanes (A) and (B)
, The polymerization process or after the polymerization, if necessary, a colorant,
One or more additives such as a lubricant, a crystallization nucleating agent, a flame retardant, an ultraviolet absorber, an antioxidant, a weather resistance improver, a hydrolysis inhibitor and an antifungal agent may be appropriately added.

The nitrogen atom content of the thermoplastic polyurethane (A) must be 2.5% by weight or less. When the nitrogen atom content exceeds 2.5% by weight, the hardness of the resulting thermoplastic polyurethane composition becomes high, and a molded product such as a stretchable film or sheet having excellent flexibility and elastic recovery is obtained. I can't.

On the other hand, the nitrogen atom content of the thermoplastic polyurethane (B) must be 3.5% by weight or more. If the nitrogen atom content is less than 3.5% by weight, the blocking resistance of the resulting thermoplastic polyurethane composition is reduced.

The logarithmic viscosity of the thermoplastic polyurethane (A) is not particularly limited, but the logarithmic viscosity of the resulting thermoplastic polyurethane composition is more excellent in uniformity, mechanical performance, elastic recovery, blocking resistance and the like. Viscosity is 0.7
It is preferably in the range of to 1.5 dl / g.

The inherent viscosity of the thermoplastic polyurethane (B) must be 0.9 dl / g or less. When the logarithmic viscosity is more than 0.9 dl / g, the melt fluidity is low and the mixing property with the thermoplastic polyurethane (A) is poor, so that it is difficult to obtain a thermoplastic polyurethane composition having excellent blocking resistance. Furthermore, when molded into a molded product such as a film or a sheet, lumps and the like due to unmelted material are likely to occur. Further, there is no particular lower limit to the logarithmic viscosity of the thermoplastic polyurethane (B), but if the difference in the logarithmic viscosity from the thermoplastic polyurethane (A) becomes too large, the resulting thermoplastic polyurethane composition tends to be non-uniform,
The logarithmic viscosity is preferably 0.4 dl / g or more because it is difficult to obtain a homogeneous film or sheet when molded. The logarithmic viscosity referred to in the present specification means that a polyurethane is added to an N, N-dimethylformamide solution containing 0.05 mol / l of n-butylamine and the concentration of polyurethane is 0.5 g / d.
It is the value when it was dissolved so as to be 1 and measured at 30 ° C.

The thermoplastic polyurethane (B) shows an endothermic peak in the range of 200 to 220 ° C. by differential scanning calorimetry (DSC), and the enthalpy of crystallization (ΔH) determined from this endothermic peak is 2 to 15 J / g. Must be within the range. When the endothermic peak temperature is less than 220 ° C. or the crystallization enthalpy (ΔH) is less than 2 J / g, the resulting thermoplastic polyurethane composition has poor blocking resistance. On the other hand, when the endothermic peak temperature exceeds 220 ° C, or the crystallization enthalpy (ΔH) is 15 J
If it exceeds / g, unmelted matter is liable to be generated in the obtained thermoplastic polyurethane composition, and lumps are generated when formed into a film, sheet or the like. Also, the blocking resistance tends to be poor.

The aromatic vinyl compound-conjugated diene block copolymer (C) [hereinafter sometimes referred to as block copolymer (C)] has at least one polymer block composed of an aromatic vinyl compound, preferably Has two or more,
And at least one polymer block composed of a conjugated diene
It is a block copolymer having one or more. The distribution of the aromatic vinyl compound in the block copolymer (C) may be random, tapered, partially block-shaped, or a mixed type thereof. Further, the molecular structure of the block copolymer (C) may be linear, branched or radial.

In the block copolymer (C), the content of the aromatic vinyl compound is preferably 5 to 50% by weight, more preferably 10 to 40% by weight. When the content of the aromatic vinyl compound in the block copolymer (C) is less than 5% by weight, the thermoplastic polyurethane composition obtained has poor blocking resistance. On the other hand, the content of aromatic vinyl compound in the block copolymer (C) is 5
When it exceeds 0% by weight, the dispersibility in thermoplastic polyurethane decreases, so that the molded article such as a film or sheet made of the thermoplastic polyurethane composition obtained is apt to have a poor appearance, and further has flexibility and elasticity recovery. Inferior in sex.

Examples of the aromatic vinyl compound constituting the block copolymer (C) include styrene, α-methylstyrene, styrene in which the benzene nucleus is substituted with alkyl and / or halogen, and particularly styrene. Preferably. Further, the block copolymer (C)
As the conjugated diene that constitutes 1,3-butadiene,
2-methyl-1,3-butadiene (also known as isoprene), 1,3-pentadiene, 2,3-dimethyl-1,
3-butadiene, 2-neopentyl-1,3-butadiene, 2-chloro-1,3-butadiene and the like can be mentioned, with 1,3-butadiene and / or 2-methyl-1,3-butadiene being preferred.

The melt flow rate (MI: 200 ° C., 5 kg load) of the block copolymer (C) is preferably 30 g / min or less, more preferably 10 g / min or less, and 5 g / min or less. Is more preferable.
The melt flow rate of the block copolymer (C) is 30 g
If it is greater than / min, the flexibility of molded products such as films and sheets made of the resulting thermoplastic polyurethane composition,
Elastic recovery, mechanical properties, etc. are likely to deteriorate, and film-forming properties during the production of films and sheets are likely to be poor. The lower limit of the melt flow rate of the block copolymer (C) is not particularly limited, but is preferably 0.1 g / min or more. Furthermore, it is preferable that the block copolymer (C) has a hardness (JIS A hardness) of 30 to 80 from the viewpoint of elastic recovery and flexibility.

The thermoplastic polyurethane composition of the present invention comprises:
Based on the total weight of the thermoplastic polyurethane (A), the thermoplastic polyurethane (B) and the block copolymer (C), 50 to 90% by weight of the thermoplastic polyurethane (A) and 10 to 10 of the thermoplastic polyurethane (B). It is necessary to contain 40% by weight and the block copolymer (C) in an amount of 5 to 30% by weight, and the thermoplastic polyurethane (A) is included in an amount of 55 to 90% by weight and the thermoplastic polyurethane (B) is included. It is preferable to contain 10 to 40% by weight and the block copolymer (C) in a ratio of 5 to 20% by weight.

In the thermoplastic polyurethane composition of the present invention, when the content of the thermoplastic polyurethane (A) is less than 50% by weight, the hardness of the thermoplastic polyurethane composition becomes high, and the flexibility and elastic recovery of the molded product are obtained. Sex decreases. On the other hand, the content of thermoplastic polyurethane (A) is 90% by weight.
If it exceeds the above, the blocking resistance of the thermoplastic polyurethane composition is poor, and when it is formed into a film or sheet,
Winding up and rewinding becomes difficult.

When the content of the thermoplastic polyurethane (B) is less than 10% by weight, the blocking resistance of the thermoplastic polyurethane composition is inferior, and the thermoplastic polyurethane composition is wound up and rewound when it is formed into a film or a sheet. Will be difficult. On the other hand, the content of thermoplastic polyurethane (B) is 40% by weight.
If it exceeds, the flexibility and elastic recovery of the molded article such as a film or sheet obtained from the thermoplastic polyurethane composition deteriorates.

Further, if the content of the block copolymer (C) is less than 5% by weight, the blocking resistance of the thermoplastic polyurethane composition and the flexibility of the molded article tend to be poor. On the other hand, when the content of the block copolymer (C) exceeds 30% by weight, the blocking resistance of the thermoplastic polyurethane composition is poor and the mechanical properties such as strength are deteriorated.

The thermoplastic polyurethane composition of the present invention comprises
In addition to the above-mentioned thermoplastic polyurethane (A), thermoplastic polyurethane (B) and block copolymer (C), a higher fatty acid bisamide (D) is added to the above-mentioned thermoplastic polyurethane (A) based on the total weight of (A) to (C). It is preferably contained in a proportion of 3 to 5% by weight. By containing the higher fatty acid bisamide (D) in this proportion, the non-adhesiveness, blocking resistance and releasability of the thermoplastic polyurethane composition are further improved. When the content of the higher fatty acid bisamide (D) exceeds 5% by weight, the non-adhesiveness, the blocking resistance and the releasability are improved, but the higher fatty acid bisamide is fried out on the surface of a molded article such as a film or a sheet. However, the surface condition deteriorates.

The higher fatty acid bisamide (D) is preferably a higher fatty acid bisamide obtained by reacting a saturated higher fatty acid having 14 to 35 carbon atoms with an aliphatic diamine having 1 to 10 carbon atoms. Examples of saturated higher fatty acids having 14 to 35 carbon atoms in that case include myristic acid, pentadecyl acid, palmitic acid, heptadecyl acid, stearic acid, nonadecanoic acid, arachidic acid, behenic acid, lignoceric acid,
Cetic acid, cerotic acid, heptacosanoic acid, montanic acid,
Melic acid and the like can be mentioned, and also has 1 to 1 carbon atoms.
Examples of the aliphatic diamine of 0 are methylenediamine,
Examples thereof include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane and 1,10-diaminodecane. . Among the higher fatty acid bisamides obtained by the reaction of the above saturated higher fatty acid and fatty acid diamine, methylenebisstearic acid amide, ethylenebisstearic acid amide, tetramethylenebisstearic acid amide, hexanemethylenebisstearic acid amide, ethylenebismontane Acid amide,
Tetramethylenebismontanic acid amide and hexanemethylenebismontanic acid amide are preferable, and methylenebisstearic acid amide and ethylenebisstearic acid amide are more preferable. These higher fatty acid bisamides may be used alone or in combination of two or more kinds.

The thermoplastic polyurethane composition of the present invention comprises
Using the above-mentioned thermoplastic polyurethane (A), thermoplastic polyurethane (B), block copolymer (C) and optionally higher fatty acid bisamide (D), it can be produced by a usual polymer blending method. it can. For example, (A), (B), (C) and optionally (D)
Is pre-mixed at a predetermined ratio using a vertical or horizontal mixer that is usually used for mixing resin materials, and then a single-screw or twin-screw extruder, mixing roll, Banbury mixer, etc. are used. It is manufactured by melt-kneading under heating in a batch system or a continuous system. Upon mixing, if necessary, additives such as lubricants such as montanic acid wax, fillers, ultraviolet absorbers, antioxidants, plasticizers, antistatic agents, hydrolysis inhibitors, pigments, etc. You may add in the range which does not impair an effect.

The thermoplastic polyurethane composition of the present invention comprises
Hot-melt molding and heat processing are possible, and various molded products such as films and sheets can be smoothly manufactured by any molding method such as extrusion molding, injection molding, blow molding and calendar molding. In particular, when a film, sheet or the like is produced from the thermoplastic polyurethane composition of the present invention using a T-die type extruder or an inflation extruder, blocking occurs between the extruded films and sheets. Since it does not occur, it can be directly extruded and wound up without using release paper or the like, and the wound film or sheet can be easily rewound. Further, when a film is produced from the thermoplastic polyurethane composition of the present invention, the film forming stability is good, and therefore it is possible to reduce the film thickness.

Molded products such as films and sheets obtained from the thermoplastic polyurethane composition of the present invention are excellent in flexibility, elastic recovery property, mechanical strength, etc., and are therefore used for paper diapers, sanitary napkins, and sealing. It can be effectively used for various applications such as stretch film used for dustproofing; general-purpose conveyor belts, various keyboard sheets, sheet applications for laminated products and the like.

[0043]

EXAMPLES The present invention will now be specifically described with reference to examples, but the present invention is not limited thereto. In the following examples and comparative examples, the nitrogen atom content, the logarithmic viscosity, and the differential scanning calorimetry (D
SC); The hardness, blocking resistance, breaking strength, surface condition, and residual strain of the molded article made of the thermoplastic polyurethane composition were measured or evaluated by the following methods.

[Nitrogen atom content rate] It was determined by elemental analysis of the thermoplastic polyurethane using an elemental analyzer (240-2 type manufactured by Perkin Elmer Co., Ltd.).

[Logarithmic Viscosity] A thermoplastic polyurethane is added to an N, N-dimethylformamide solution at a concentration of 0.5 g / dl.
Dissolve and use an Ostwald viscometer to
The flow-down time of the polyurethane solution at 30 ° C. was measured, and the logarithmic viscosity was determined by the following formula.

Logarithmic viscosity = {ln (t / t ₀ )} / c [where t is the flow-down time (seconds) of the polyurethane solution, t
₀ represents the flow time of the solvent (seconds), and c represents the concentration of the polyurethane solution (g / dl). ]

[Differential Scanning Calorimetry (DSC)] The melting enthalpy of the thermoplastic polyurethane (B) was measured using a differential scanning calorimeter (manufactured by Mettler; DSC30).
The amount of sample at the time of measurement was set to about 10 mg, measured at a temperature rising rate of 10 ° C./min in a nitrogen gas atmosphere, and the crystallization enthalpy (ΔH) was calculated from the temperature of the endothermic peak and the peak area of the endothermic peak at 200 to 220 ° C. ) Was asked.

[Hardness] Two disc-shaped products (diameter 120 mm, thickness 2 mm) obtained by injection molding were used, and the hardness was measured by a Shore A hardness meter according to JIS K 6301.

[Blocking Resistance] A film having a thickness of about 38 μm was produced by using a T-die type extrusion molding machine (25 mmφ) and wound up without using a release paper. The degree of blocking resistance was observed and judged according to the evaluation criteria shown in Table 1 below.

[0050]

[Table 1]

[Breaking Strength] T-die type extrusion molding machine (25 m
mφ) was used to manufacture a film, and the film was wound up without using a release paper, and the thickness was about 38 μm.
Based on K7311, the tensile breaking strength in the machine axis direction (MD direction) was measured.

[Surface Condition] T-die type extrusion molding machine (25 m
mφ) was used to manufacture a film, and the film was wound up without using release paper, and the surface condition of the film was observed. Some were marked as x.

[Residual Strain] T-die type extrusion molding machine (25 m
mφ) was used to produce a film, and the film was wound up without using release paper and the thickness was about 38 μm. A sample piece (25 mm × 100 m) cut into a strip in the MD direction was used.
m) was prepared. Using this sample piece, 23 ℃, 65%
50 mm between chucks and 300 pulling speed under RH conditions
After 100% elongation at mm / min, it was immediately returned to the original position at a speed of 100 mm / min. After repeating this operation twice, the sample length L (mm) was measured, and the residual strain was determined according to the following formula.

Residual strain (%) = [(L-50) / 50] × 100

Abbreviations and compound names used in the following Examples and Comparative Examples are shown in Table 2 below.

[0056]

[Table 2]

Example 1 PMPA, BD and MDI having a number average molecular weight of 3500 as a polyester diol were mixed at 85 ° C. and 50, respectively.
From the storage tank heated to 50 ° C, the polyesterdiol / MDI / BD molar ratio becomes 1/3/2,
It was continuously supplied to a twin-screw extruder rotating in the coaxial direction by a metering pump to carry out continuous melt polymerization. At this time, the heating zone of the extruder was divided into three zones of a front part, a middle part and a rear part, and the temperature of the middle part was set to 230 ° C and the temperature of the rear part was set to 200 ° C. The resulting polyurethane melt was continuously extruded into water in strands, then cut with a pelletizer and the pellets dried at 80 ° C. for 6 hours. The thus-obtained thermoplastic polyurethane [corresponding to thermoplastic polyurethane (A)] had a nitrogen atom content of 1.9% by weight. PBA having a number average molecular weight of 2000 as a polyester diol was placed in a reaction vessel, heated to 50 ° C., and then MDI heated to 50 ° C. with stirring had a PBA / MDI molar ratio of 1 / 7.1.
And added for 5 minutes to react. In addition, 50
BD heated to 0 ° C., PBA / MDI / BD = 1/7.
It was added so that the ratio became 1 / 6.1 and reacted for 5 minutes. After the reaction product was transferred onto a heating plate at 140 ° C. to complete the reaction, the reaction product on the obtained plate was crushed and further pelletized by a single-screw extruder to obtain a thermoplastic polyurethane [thermoplastic polyurethane ( Corresponding to B)] was obtained. This thermoplastic polyurethane has a nitrogen atom content of 4.6% by weight, an inherent viscosity of 0.6 dl / g, and a differential scanning calorimetry (DS).
C) showed an endothermic peak at 205 ° C., and the crystallization enthalpy (ΔH) determined from this endothermic peak was 9.3 J / g. The dry pellets of the thermoplastic polyurethane (A) and the thermoplastic polyurethane (B) and the block copolymer (SIS) (C) are contained in a weight ratio of (A), (B) and (C) of 70:30:10. After blending so as to become, single-screw extruder (25 mmφ, cylinder temperature: 180-2
00 ° C., die temperature: 200 ° C.) and melt-kneaded to produce a thermoplastic polyurethane composition. Further, this thermoplastic polyurethane composition was extruded from a T-die type extruder and continuously wound up through a cooling roll (surface temperature: 30 to 40 ° C.) to give a thickness of about 38 μm and a width of 300.
mm film was produced. Table 4 below shows the results of evaluation of the obtained molded products.

Examples 2-6, Comparative Examples 1-5 Thermoplastic polyurethanes (A), thermoplastic polyurethanes (B), block copolymers (SIS) (C) and higher grades shown in Tables 3 and 4 below. Aliphatic bisamide (ES
Example 1 except that BA) and (D) are used in a predetermined ratio.
A thermoplastic polyurethane composition was produced in the same manner as in.
Table 4 below shows the results of evaluation of the obtained molded products.

[0059]

[Table 3]

[0060]

[Table 4]

As is clear from Tables 3 and 4, the films obtained from the thermoplastic polyurethane compositions of Examples 1 to 6 of the present invention are not only excellent in flexibility, elastic recovery and mechanical strength. It can be seen that the anti-blocking property is also excellent. On the other hand, in the case of only the thermoplastic polyurethane (A) (Comparative Example 1), the number average molecular weight of the polyester diol of the thermoplastic polyurethane (B) was 1,500.
When it is less than (Comparative Example 3), the blocking resistance of the obtained film is poor. When the thermoplastic polyurethane (B) shows an endothermic peak at a temperature higher than 220 ° C. by differential scanning calorimetry (DSC), or the crystallization energy (Δ
When H) is more than 15 J / g (Comparative Example 2), the smoothness and elastic recovery of the surface state of the obtained film are poor. When the content of the thermoplastic polyurethane (B) exceeds 40% by weight (Comparative Example 4), the hardness of the obtained film is high, the residual strain is large, and a flexible film cannot be obtained. The content ratio of the block copolymer (C) is 3
When it exceeds 0% by weight (Comparative Example 5), the smoothness, elastic recovery, blocking resistance and strength of the surface state of the obtained film are poor.

[0062]

INDUSTRIAL APPLICABILITY The thermoplastic polyurethane composition of the present invention is non-adhesive, has excellent blocking resistance and release properties, and can be smoothly formed without using release paper when forming a film, sheet or the like. It can be rolled up and the rolled molded article can be rewound without blocking. Molded articles such as films and sheets made of the thermoplastic polyurethane composition of the present invention are also excellent in flexibility, elastic recovery and mechanical properties, and the films and sheets are particularly useful as stretchable films or sheets. . further,
The thermoplastic polyurethane composition of the present invention containing a small amount of higher fatty acid bisamide is further excellent in its non-adhesiveness, blocking resistance, and releasability.

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Claims (4)

[Claims] 1. A number average molecular weight of 2,000 to 8,000, and 30 mol% or more of diol units is 3-methyl-1,
Thermoplastic polyurethane (A) having a nitrogen atom content of 2.5% by weight or less, obtained by reacting a polyester diol composed of a 5-pentanediol unit, an organic diisocyanate and a chain extender; number average molecular weight of 1500 to 40
No. 00 polyester diol, an organic diisocyanate, and a chain extender, which have a nitrogen atom content of 3.5 wt% or more and an inherent viscosity of 0.9 dl / g or less, and are measured by differential scanning calorimetry (DSC). A thermoplastic polyurethane (B) having an endothermic peak in the range of 200 to 220 ° C. and a crystallization enthalpy (ΔH) determined from this endothermic peak of 2 to 15 J / g; and an aromatic vinyl compound-
A thermoplastic polyurethane composition comprising a conjugated diene block copolymer (C), wherein the thermoplastic polyurethane (A) is 50 to 90 based on the total weight of (A) to (C).
% By weight, 10 to 40% by weight of the thermoplastic polyurethane (B) and 5 to 30% by weight of the aromatic vinyl compound-conjugated diene block copolymer (C). Stuff. 2. Further, based on the total weight of the thermoplastic polyurethane (A), the thermoplastic polyurethane (B) and the aromatic vinyl compound-conjugated diene block copolymer (C), the higher fatty acid bisamide (D) is further added in an amount of 0. The thermoplastic polyurethane composition according to claim 1, which is contained in a proportion of 3 to 5% by weight. 3. A molded product comprising the thermoplastic polyurethane composition according to claim 1. 4. The molded product according to claim 3, which is a film or a sheet.