JPH09208820A - Thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoplastic resin composition which is excellent in film-forming stability, mold release properties and blocking resistance and can smoothly produce a molded article, such as a film or sheet, and a laminate excellent in mechanical characteristics, such as elastic recovery, strength and extensibility, and flexibility. SOLUTION: This composition consists of 70-98wt.% thermoplastic polyurethane (A) having a JIS A hardness of 55 to 85 and obtained by reacting a polyester diol containing at least 30mol% branched 6-9C diol units, consisting of diol units and dicarboxylic acid units, and having a number-average molecular weight of 1,000 to 6,000, an organic diisocyanate and a chain extender, and 2-30wt.% olefin elastomer (B) having a JIS A hardness of 40 to 80. The molded article, such as a film or sheet, is produced from the composition. The laminate consists of a melt molded layer comprising the composition and a fibrous base layer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic resin composition comprising a specific thermoplastic polyurethane and an olefin elastomer, a molded article such as a film or sheet comprising the thermoplastic resin composition, and the thermoplastic resin composition. The present invention relates to a laminate comprising a melt-molded layer composed of and a fibrous substrate layer. The thermoplastic resin composition of the present invention has film-forming stability,
It has excellent blocking resistance and release properties, and can be used to smoothly and easily manufacture molded products such as films and sheets. Molded products such as films and sheets obtained from the thermoplastic resin composition of the present invention have excellent properties such as elastic recovery, strength and elongation, and flexibility, and are useful as stretchable films or sheets. Furthermore, the thermoplastic resin composition of the present invention is also useful as a raw material for manufacturing a laminate with a fibrous substrate.

[0002]

2. Description of the Related Art Thermoplastic polyurethanes have elastic recoverability,
Although it is a material with excellent performance in terms of strength and elongation, flexibility, etc., it has strong adhesiveness and is liable to cause sticking. Therefore, for example, when a film or sheet is manufactured by extrusion molding, etc. Peelability is poor and it is difficult to form a stable film. Furthermore, when a thermoplastic polyurethane is melt-extruded in a film shape or a sheet shape onto a fibrous base material made of a non-woven fabric or other fiber cloth to produce a laminated body, when the laminated body produced is wound up, sticking occurs. Occurs, which makes it difficult to unwind the rolled-up laminate, or it becomes impossible and unusable. Especially,
A low-hardness thermoplastic polyurethane having excellent flexibility has a large stickiness and is very inconvenient to handle. Therefore, in order to reduce the stickiness of the thermoplastic polyurethane, it has been proposed to add 1 to 15% by weight of a high-density polyethylene resin (see Japanese Patent Laid-Open No. 3-185062).

[0003]

However, since thermoplastic polyurethane and high-density polyethylene resin have low compatibility, when a resin composition composed of thermoplastic polyurethane and high-density polyethylene resin is subjected to film forming, Membrane stability is poor and it is difficult to form a smooth film. This difficulty of forming a film becomes particularly remarkable when a flexible thermoplastic polyurethane having a low hardness is used. Furthermore, when the thermoplastic polyurethane is blended with a high-density polyethylene resin, the excellent mechanical properties originally possessed by the thermoplastic polyurethane are impaired.

The object of the present invention is to obtain the excellent properties inherent in thermoplastic polyurethane, in particular the elastic recovery, the strength and elongation,
Excellent film-forming stability, releasability, blocking resistance, etc. without sacrificing mechanical properties such as flexibility, film,
It is intended to provide a thermoplastic resin composition capable of smoothly producing a molded product such as a sheet and a laminate. Further, an object of the present invention is to provide a molded article such as a film or sheet made of the thermoplastic resin composition, and a laminate comprising a melt-molded layer made of the thermoplastic resin composition and a fibrous substrate layer. It is in.

[0005]

Means for Solving the Problems As a result of extensive studies by the present inventors in order to achieve the above-mentioned object, by blending an olefinic elastomer having a specific hardness with a thermoplastic polyurethane, a low-hardness and flexible thermal Even in the case of plastic polyurethane, it has excellent film-forming stability, release properties, blocking resistance, etc. without impairing its mechanical properties, and is a thermoplastic resin that can smoothly produce molded products such as films and sheets, and laminates. It was found that a resin composition can be obtained, and the present invention was completed based on these findings.

That is, according to the present invention, the number average molecular weight of 10 is composed of a diol unit containing a branched diol unit having 6 to 9 carbon atoms in an amount of 30 mol% or more and a dicarboxylic acid unit.
JIS obtained by reacting 100 to 6000 polyester diol, organic diisocyanate and chain extender
Thermoplastic polyurethane (A) 70 having A hardness of 55 to 85
To 98% by weight, and 2 to 30% by weight of olefin elastomer (B) having JIS A hardness of 40 to 80%.

The present invention also provides a molded product such as a film or sheet made of the above thermoplastic resin composition, and a laminate comprising a melt-molded layer made of the above thermoplastic resin composition and a fibrous substrate layer. is there.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polyester diol used for producing the thermoplastic polyurethane (A) is substantially composed of diol units and dicarboxylic acid units. The diol unit constituting the polyester diol needs to contain branched diol units having 6 to 9 carbon atoms in an amount of 30 mol% or more, preferably 50 mol% or more, based on the total diol units. . The number of branched diol units having 6 to 9 carbon atoms is 3 with respect to all diol units.
By using the polyester diol containing 0 mol% or more, a thermoplastic resin composition having excellent mechanical properties such as elastic recovery, strength and flexibility can be obtained.

Examples of branched diol units having 6 to 9 carbon atoms include units derived from 3-methyl-1,5-pentanediol, 2-methyl-1,8-octanediol and the like. It is possible to use one or more of these. Examples of the diol unit that can be used in combination with the branched diol unit having 6 to 9 carbon atoms include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, and 1,9-nonanediol. Units derived from saturated aliphatic diols such as Among these, units derived from 1,4-butanediol and 1,6-hexanediol are preferable because the effects derived from branched diol units having 6 to 9 carbon atoms are not easily lost.

Examples of the dicarboxylic acid unit constituting the polyester diol include glutaric acid, adipic acid,
Pimelic acid, suberic acid, azelaic acid, sebacic acid,
Decanedicarboxylic acid, 2-methylsuccinic acid, 2-methyladipic acid, 3-methyladipic acid, 3-methylpentanedioic acid, 2-methyloctanedioic acid and the like has 6 to 1 carbon atoms.
2 aliphatic dicarboxylic acids; units derived from aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, etc., among which 1
Species or two or more can be used. Among these, units derived from an aliphatic dicarboxylic acid having 6 to 10 carbon atoms such as adipic acid, azelaic acid and sebacic acid are preferable.

The number average molecular weight of polyester diol is 1
000-6000, preferably 1500-5000. Number average molecular weight of polyester diol is 1
When it is less than 000, the thermoplastic resin composition has insufficient performance such as elastic recovery, flexibility, and cold resistance. on the other hand,
When the number average molecular weight of the polyester diol exceeds 6000, a rapid increase in viscosity tends to occur when the thermoplastic resin composition is melted, resulting in poor moldability. The number average molecular weight of the polyester diols referred to in the present specification is the number average molecular weight calculated based on the hydroxyl value measured according to JIS K 1557.

The method for producing the polyester diol is not particularly limited, and the polyester diol can be produced by polycondensation using 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 may be carried out in the presence of a titanium-based or tin-based polycondensation catalyst. However, when a titanium-based polycondensation catalyst is used, it is included in the polyester diol after completion of the polycondensation reaction. It is preferable to deactivate the titanium-based polycondensation catalyst. By producing a thermoplastic polyurethane (A) using a polyester diol in which a titanium-based polycondensation catalyst has been deactivated, a polyurethane can be formed even if the thermoplastic polyurethane (A) is kept in a molten state at a high temperature during molding. Since the deterioration of the block property of the hard segment and the soft segment is suppressed, various properties such as heat resistance and elastic recovery property of the thermoplastic polyurethane (A) are retained in the molded products such as films and sheets and laminated products. It can be effectively used as it is on the body.

When the titanium-based polycondensation catalyst is used in the production of the polyester diol, any of the titanium-based polycondensation catalysts conventionally used in the production of polyester diols can be used, and the titanium-based polycondensation catalyst is not particularly limited. Examples of polycondensation catalysts include titanic acid, tetraalkoxytitanium compounds, titanium acylate compounds, titanium chelate compounds and the like. More specifically, tetraisopropyl titanate, tetra-n
Tetraalkoxy titanium compounds such as butyl titanate, tetra-2-ethylhexyl titanate and tetrastearyl titanate; titanium acylate compounds such as polyhydroxy titanium stearate and polyisopropoxy titanium stearate; titanium acetyl acetate, triethanolamine titanate, titanium Examples thereof include titanium chelate compounds such as ammonium lactate, titanium ethyl lactate, and 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.

The titanium polycondensation catalyst contained in the polyester diol produced by using the titanium polycondensation catalyst can be deactivated by, for example, bringing the polyester diol into contact with water under heating to deactivate it. A method of treating the polyester diol with a phosphorus compound such as phosphoric acid, phosphoric acid ester, phosphorous acid, and phosphorous acid ester can be mentioned. Among them, the former method of contacting with water under heating is preferable. As a method of deactivating the titanium-based polycondensation catalyst by bringing it into contact with water, 1% by weight or more of water is added to the polyester diol obtained by the polycondensation reaction (usually 1
˜4% by weight) and stirring at a temperature of 80 to 150 ° C., and a method of stirring at a temperature of 100 to 150 ° C. while passing water vapor through the polyester diol.

The type of organic diisocyanate used for producing the thermoplastic polyurethane (A) is not particularly limited, and any of the organic diisocyanates conventionally used for producing ordinary thermoplastic polyurethane can be used.
One or more of aromatic diisocyanates, alicyclic diisocyanates and aliphatic diisocyanates having a molecular weight of 500 or less are preferably used. Examples of organic diisocyanates include 4,4′-diphenylmethane diisocyanate, p-phenylene diisocyanate, tolylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 4,
4'-dicyclohexyl methane diisocyanate etc. can be mentioned. Among these, it is preferable to use 4,4′-diphenylmethane diisocyanate.

As the chain extender used in the production of the thermoplastic polyurethane (A), any of the chain extenders conventionally used in the production of ordinary thermoplastic polyurethane can be used, and the type thereof is particularly Not limited. Among these, low molecular weight compounds having a molecular weight of 300 or less (for example, aliphatic diols, alicyclic diols and aromatic diols having a molecular weight of 300 or less) having two or more active hydrogen atoms capable of reacting with an isocyanate group are preferably used. . Specific examples of preferable chain extenders include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (2-hydroxyethoxy) benzene, 1,4-cyclohexanediol, Examples thereof include diols such as bis- (β-hydroxyethyl) terephthalate and xylylene glycol. These chain extenders may be used alone or in combination of two or more kinds. Among these, it is preferable to use an aliphatic diol having 2 to 10 carbon atoms as a chain extender, and it is more preferable to use 1,4-butanediol.

The thermoplastic polyurethane (A) contains the above-mentioned polyester diol, organic diisocyanate and chain extender in the number of moles of isocyanate groups of the organic diisocyanate and the total number of moles of hydroxyl groups contained in the polymer diol and the chain extender. The ratio (the number of moles of isocyanate group / the number of moles of hydroxyl group) is 0.95 to 1.30, particularly 0.96.
It is preferably obtained by reacting within the range of about 1.10.

JIS A for thermoplastic polyurethane (A)
The hardness is 55 to 85, preferably 60 to 80. When the thermoplastic polyurethane (A) having a JIS A hardness within this range is used, the thermoplastic resin composition and the molded article made thereof can have sufficient flexibility and good mechanical properties.

The method for producing the thermoplastic polyurethane (A) is not particularly limited, and the above-mentioned polyester diol, organic diisocyanate and chain extender are used, and the known urethanization reaction technique is used to carry out the prepolymer method and one-shot method. It may be produced by any method. Among them, it is preferable to carry out melt polymerization substantially in the absence of a solvent, and particularly preferable is a continuous melt polymerization method using a multi-screw extruder. The melt polymerization temperature is not particularly limited, but is 180 ° C.
The range of ˜260 ° C. is preferable.

As the olefinic elastomer (B) used in the present invention, any of the olefinic elastomers known before this application can be used. For example, ethylene-propylene copolymer rubber (EPM); ethylene-propylene-diene. Copolymer rubber (EPDM); hard segment of polyethylene and / or polypropylene and EPM
Olefin-based elastomer consisting of soft segment of EPDM and / or EPDM; elastomer consisting of hard segment of polyethylene and soft segment of ethylene-vinyl acetate copolymer and / or ethylene-ethyl acrylate copolymer; butyl rubber; soft segment mainly amorphous Elastomers and the like, which are volatile polyethylene and whose cross-linking points are metal ion bonds, can be mentioned. Among these, EPDM or polyethylene and /
Alternatively, an olefin-based elastomer composed of a hard segment of polypropylene and a soft segment of EPM and / or EPDM is preferable. The olefin-based elastomer comprising the hard segment of polyethylene and / or polypropylene and the soft segment of EPM and / or EPDM has a hard segment and a soft segment bonded in the form of a block copolymer, or is in a blended form. May be. The olefin elastomer in which the hard segment and the soft segment are in a blended form is a simple blend type in which both segments are simply mixed, a partially crosslinked type in which a crosslinker such as peroxide is partially crosslinked, or a It may be a completely crosslinked type which is completely crosslinked with a crosslinking agent such as oxide. In the olefin-based elastomer composed of EPDM or the olefin-based elastomer having EPDM as a soft segment, examples of the diene compound forming the EPDM include one or more kinds such as ethylidene norbornene, 1,4-hexadiene and dicyclopentadiene. It is preferably used.

JIS of olefin elastomer (B)
The A hardness is 40 to 80, and preferably 45 to 75. Olefin-based elastomers having a JIS A hardness within this range have good compatibility with thermoplastic polyurethane (A), and by using such olefin-based elastomers, flexibility, film-forming stability, and non-stickiness are achieved. An excellent thermoplastic resin composition is obtained.

The thermoplastic resin composition of the present invention contains 70 to 98% by weight of the thermoplastic polyurethane (A) and the olefin elastomer, based on the total weight of the thermoplastic polyurethane (A) and the olefin elastomer (B). It is necessary that (B) is contained in a proportion of 2 to 30% by weight, and the thermoplastic polyurethane (A) is contained in a proportion of 80 to
97 wt% and olefinic elastomer (B) 3
It is preferably contained in a proportion of ˜20% by weight. When the content of the thermoplastic polyurethane (A) is less than 70% by weight [when the content of the olefinic elastomer (B) exceeds 30% by weight], the film-forming stability of the thermoplastic resin composition is poor, Furthermore, the elastic recovery properties, strength and elongation of molded products such as films, sheets and laminates are reduced. On the other hand, when the content of the thermoplastic polyurethane (A) exceeds 98% by weight [when the content of the olefin elastomer (B) is less than 2% by weight], the stickiness of the thermoplastic resin composition becomes high. When manufacturing a film, sheet, laminate, etc., it becomes difficult to wind and unwind, and when manufacturing a molded product, it becomes difficult to release the molded product from the mold.

The thermoplastic resin composition of the present invention contains, in addition to the above-mentioned components, an antioxidant, an ultraviolet absorber, and
One or more additives such as pigments, lubricants, fillers, antistatic agents, plasticizers, flame retardants, and antifungal agents may be contained within a range that does not impair the effects of the present invention.

The thermoplastic resin composition of the present invention is prepared by mixing the above-mentioned thermoplastic polyurethane (A) and olefin elastomer (B) and, if necessary, other additives by a usual polymer blending method. It can be manufactured. For example, using a vertical or horizontal mixer that is usually used for mixing polymers, after premixing at the above-mentioned predetermined ratio, using a single-screw extruder, a twin-screw extruder, a mixing roll, a Banbury mixer, etc. It can be produced by batch kneading or continuous kneading under heating. In particular, when performing heat kneading using an extruder,
It may be extruded in a strand shape and then cut into an appropriate length to form a pellet or other granular material. In addition to the above-mentioned method, the thermoplastic resin composition of the present invention may be added by a method of adding the olefinic elastomer (B) and, if necessary, other additives during the polymerization of the thermoplastic polyurethane (A). You may manufacture a thing.

The thermoplastic resin composition of the present invention can be melt-molded and heat-processed, and various molded articles can be smoothly processed by any molding method such as extrusion molding, injection molding, blow molding, calender molding and casting. Can be manufactured. In particular, when a film or sheet is manufactured using a T-die type extrusion molding machine or an inflation extrusion molding machine, the film can be stably formed because of its excellent releasability from a metal roll. Further, even when a molded product is manufactured by injection molding or other molding, the thermoplastic resin composition of the present invention has excellent mold releasability, so that the molded product can be easily demolded. Even when a mold agent is used, the amount of the release agent used and the number of times of application to the inner surface of the mold can be reduced as compared with the conventional molding of thermoplastic polyurethane.

Further, the thermoplastic resin composition of the present invention comprises
It is also suitable as a raw material for manufacturing a laminate with a fibrous substrate made of a non-woven fabric or other fiber cloth. For example, when a thermoplastic resin composition of the present invention is melt extruded on a fibrous substrate in a film or sheet form to produce a laminate, the surface of the melt-molded layer made of the thermoplastic resin composition is non-adhesive. Since it is excellent in releasing property and does not cause blocking, such a film-shaped or sheet-shaped laminated body can be smoothly wound up, and further, the wound-up laminated body can be easily rewound.

Molded articles and laminates such as films and sheets obtained by using the thermoplastic resin composition of the present invention are excellent in mechanical properties such as elastic recovery, flexibility, and elongation, and have a smooth surface. Since it has a good surface condition, it can be used for sanitary use, disposable diapers, sealing,
Elastic film applications used for dustproofing, general-purpose conveyor belts, various keyboard sheets, laminated products,
It can be effectively used for various applications such as seats for various containers and shoe soles for sports shoes and ski shoes.

[0029]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the following Examples and Comparative Examples, JIS A hardness, film-forming stability, breaking strength / elongation of film, permanent set of film, and blocking resistance of laminate were measured or evaluated by the following methods.

[JIS A hardness] The thermoplastic polyurethane was measured according to JIS K 7311, and the olefin elastomer was measured according to JIS K 7215.

[Film-forming stability] A thermoplastic resin composition containing 25
Extrude from T-die using mmφ single screw extruder (cylinder temperature: 210 ° C, die temperature: 200 ° C), 30
Film thickness 40μm through a cooling roll adjusted to a temperature of ℃
The film-forming stability when the above film was produced was evaluated according to the evaluation criteria shown in Table 1 below.

[0032]

[Table 1]

[Strength and Elongation at Break of Film] A film having a thickness of 40 μm manufactured by using a T-die type extrusion molding machine (25 mmφ) was subjected to a tensile test in accordance with JIS K 7311 to obtain a strength at break. The degree was measured.

[Permanent Strain of Film] A film having a thickness of 40 μm produced by using a T-die type extrusion molding machine (25 mmφ) was pulled at a tension rate of 200 mm / min under the conditions of a temperature of 23 ° C. and a humidity of 65% RH. Elongated by 150%, the state is maintained for 2 minutes, and then the stress is removed. The length of the test piece after standing for 10 minutes was measured, and the permanent set was calculated according to the following formula (1).

Permanent strain (%) = [(L′−L) / L] × 100 (1) (where, L is the initial length of the test piece, L ′ is the stress removed and left for 10 minutes The following shows the length of the test piece.)

[Blocking Resistance of Laminate] On a hydroentangled nonwoven fabric “Kuraflex” manufactured by Kuraray Co., Ltd., a thermoplastic resin composition is melt extruded in a film form from a T-die to produce a laminate. It was rolled up. This is 24
After being left for a period of time, the ease of rewinding by hand was evaluated according to the evaluation criteria shown in Table 2 below.

[0037]

[Table 2]

In the following Examples and Comparative Examples, each compound is indicated by the abbreviations shown in Table 3 below.

[0039]

[Table 3]

Example 1 A 25 mmφ single-screw extruder (cylinder temperature: 2) was used so that the ratio of PU-1 was 95% by weight and that of TPO-1 was 5% by weight.
10 ° C., die temperature: 200 ° C.) and melt-kneaded to obtain a thermoplastic resin composition. The film-forming stability of this thermoplastic resin composition was evaluated by the method described above. Furthermore, a film having a thickness of 40 μm was produced using a T-die type extrusion molding machine (25 mmφ), and the film was allowed to stand at 25 ° C. for 3 days, and the breaking strength / elongation and permanent strain were evaluated by the above methods. In addition, a laminate produced by melt-extruding a thermoplastic resin composition into a film shape from a T-die on a hydroentangled nonwoven fabric “Kuraflex” manufactured by Kuraray Co., Ltd. was evaluated for blocking resistance by the above method. . The results obtained are shown in Table 4 below.

Examples 2 to 4, Comparative Examples 1 to 4 Example 1 except that the compositions shown in Table 4 below were used.
With respect to the thermoplastic resin composition obtained in the same manner as described above, the film forming stability, the breaking strength and elongation of the film, the permanent set of the film, and the blocking resistance of the laminate were evaluated by the methods described above.
The results obtained are shown in Table 4 below.

[0042]

[Table 4]

[0043]

EFFECT OF THE INVENTION The thermoplastic resin composition of the present invention is excellent in film-forming stability, blocking resistance and releasability, and can smoothly and easily produce molded products such as films and sheets. . Molded products such as films and sheets obtained from the thermoplastic resin composition of the present invention have excellent properties such as elastic recovery, strength and elongation, and flexibility, and are useful as stretchable films or sheets. Furthermore, the laminate produced by melt-extruding the thermoplastic resin composition of the present invention onto a fibrous substrate has a non-adhesive surface of the melt-molded layer made of the thermoplastic resin composition, excellent releasability, and blocking. Therefore, the laminated body can be smoothly wound, and the wound laminated body can be easily rewound.

Claims (4)

[Claims] 1. A polyester diol having a number average molecular weight of 1000 to 6000, comprising a diol unit containing a branched diol unit having 6 to 9 carbon atoms in an amount of 30 mol% or more and a dicarboxylic acid unit, reacted with an organic diisocyanate and a chain extender. JIS A hardness of 55-85
70 to 98% by weight of the thermoplastic polyurethane (A), and 2 to 30% by weight of the olefin elastomer (B) having a JIS A hardness of 40 to 80. 2. A molded article made of the thermoplastic resin composition according to claim 1. 3. The molded product according to claim 2, which is a film or a sheet. 4. A laminate comprising a melt-molded layer comprising the thermoplastic resin composition according to claim 1 and a fibrous substrate layer.