JPH02120358A - Thermoplastic polyurethane resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition which can give a nonwrinkling film excellent in flexibility and hand by blending a thermoplastic polyurethane resin with a modified polyolefin resin. CONSTITUTION:A thermoplastic polyurethane resin preferably having a hardness of 80-100, a tensile strength >=200kg/cm<2> and an elongation at break >=300% is blended with a modified polyolefin resin preferably comprising a carboxylic and/or epoxy olefin copolymer in a weight ratio of 99-50 pts.wt. for the former to 1-50 pts.wt. for the latter.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a thermoplastic polyurethane resin composition, particularly a composition for elastic films that has excellent feel such as flexibility when used as a film or sheet. .

(Prior art and its problems) Conventional elastic films for body fluid treatment products such as disposable diapers are made of SBR (styrene-butadiene rubber) alone, SBR/thermoplastic polyurethane resin blend, or thermoplastic polyurethane alone. Although acid amide lubricants are added to the resin to prevent adhesion, it is not flexible (high low modulus) and has little elongation, so when used in infant disposable diapers, it does not tightly tighten the skin. Currently, elastic films are used for adults and children by changing the structure of the film blade or film, and a fully satisfactory elastic film has not yet been obtained.

(Means for Solving the Problem) As a result of intensive research by the present inventors in order to develop an elastic film made of a thermoplastic I-urethane resin composition free from the above-mentioned drawbacks, we found that the thermoplastic polyurethane resin has a carboxylic group and/or A composition containing an epoxy-based olefin copolymer has excellent compatibility, provides flexibility without losing the excellent properties of polyurethane resin, and has excellent adhesion during molding or film winding. The present inventors have discovered a composition that is both free and highly practical, and have completed the present invention.

That is, the present invention provides a thermoplastic polyurethane resin composition comprising a thermoplastic polyurethane resin (1) and a modified polyolefin resin (n), and an elastic film or sheet characterized by using this thermoplastic polyurethane resin composition. It is something to do.

(Structure) The thermoplastic polyurethane resin used in the present invention preferably has a hardness (JIS) of 80 to 100 at 25°C, particularly preferably 85 to 950, and preferably a tensile strength of 200.
kg/an2 or more, particularly preferably 300 to 500 k
g7'm2. A polyurethane resin having physical properties such that the elongation at break is preferably 300% or more, particularly preferably 400% or more, and is obtained by reacting a polyhydroxyl compound (?liol component) and an lβ-liisocyanate compound (isocyanate component). can be preferably used.

, 1? Examples of the IJ hydroxyl compound include various polyester polyols and/or polyether polyols used in the production of general urethane compounds.

The polyester polyols mentioned here include condensates of polyhydric alcohols and polyhydric crystalline carboxylic acids, condensates of hydroxycarboxylic acids and polyhydric alcohols, etc. The polyhydric alcohols used in these include, for example. Examples of the polybasic carboxylic acids include ethylene glycol, propylene glycol, butane diol, diethylene glycol, glycerin, hexanetriol, and trimethylolpronocone, and examples of polybasic carboxylic acids include adipic acid and geltaric acid.

azelaic acid, fumaric acid, maleic acid, phthalic acid,
Examples include terephthalic acid, dimer acid, and pyromellitic acid. Also useful as condensates of hydroxycarboxylic acids and polyhydric alcohols are reaction products such as castor oil, castor oil, ethylene glycol, and phlopylene glycol. Furthermore, as polyester polyols, lactone-based polyester polyols obtained by ring-opening polymerization of lactones such as ε-caprolactone can also be used.

These lactone-based polyester polyols include the polyhydric alcohols mentioned above, monocaprolactone, δ-
Any addition polymerization of one or more types of valerolactone, β-methyl-δ-valerolactone, etc. can be used.

Polyether polyols are products obtained by addition-polymerizing one or more alkylene oxides P such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran to a compound having two or more active hydrogens, and are usually Any of the known polyether polyols used in the production of polyurethane resins can be used. In this case, examples of compounds having two or more active hydrogens include, in addition to the polyhydric alcohols and polybasic carboxylic acids mentioned above, amines such as ethylenecyamine and hexamethylene diamine, ethanolamine, and furopanolamine. Examples include alkanolamines such as resorcinol, polyhydric phenols such as bisphenol, and castor oil.

The polyhydroxyl compound uses one or more of polyester polyols and polyether polyols, and further contains low molecules such as the polyhydric alcohols mentioned above! A polyhydroxy compound may also be used as a chain extender.

A polyisocyanate compound is a compound having two or more incyanate groups in the molecule, and various compounds used in the production of ordinary polyurethane resins can be used.
For example, aromatic polyisocyanate compounds such as tolylene diisocyanate, diphenylmethane diisocyanate, dianidine noisocyanate, naphthalene diiso7anate, triphenylmethane triisocyanate, bis(diisocyanatotolyl)phenylmethane, polymethylene polyphenyl polyisocyanate, and fatty acids. Examples of group-based or alicyclic-based polyisocyanate compounds include inphorone diisocyanate, dicyclohexylmethane diisocyanate (hydrogenated diphenylmethane-7 diincyanate), hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated tolylene diisocyanate, isopropylidene bis( cyclohexyl isocyanate)
etc.

The polyisocyanate compound used in the present invention may be a combination of two or more types of polyisocyanate compounds, and particularly an aromatic polyisocyanate compound may be used in combination with an aliphatic or alicyclic polyisocyanate compound.

As the polyol component of the polyurethane resin, all of the above-mentioned polyhydroxyl compounds used in the production of isocyanate group-containing urethane polymers can be used. That is, one or more of the above polyester polyols and polyether polyols can be used. Furthermore, a low molecular weight polyhydroxy compound such as the above-mentioned polyhydric alcohol can also be used in combination as a polyol component.

The modified polyolefin resin (B) of the present invention is a polyolefin resin modified with an acid or a niboxy compound, preferably a carboxyl group-containing olefin copolymer and/or an epoxy group-containing olefin copolymer. This component (B) is preferably for component (1) 99 to 50,
It is used in a ratio of 1 to 50 (weight ratio), especially (A) : (B
)=98-60:2-40.

The carboxyl group-containing olefin copolymer contains at least 50 molti, preferably 70 molti of 1-olefins, such as ethylene, propylene, butene-1, isobutyne,
Pentene-1, hexene-1, decene-1,4-methylbutene-1,4-methylinten-1,4,4-dimethylpentene-1, vinylcyclohexane, styrene, α
- methylstyrene, styrene substituted with (2) class alkyl substituents or similar compounds thereof; it is also possible to use mixtures of the above-mentioned olefins.

Copolymers obtained from ethylene and butene-1 or propylene are preferred, and commercially available products include Tafmer A series [ethylene-butene-] copolymers such as Tafmer A4085, Tafmer A4090, and Tafmer A 20090. Tafmer P series [ethylene-pro♂lene copolymer, manufactured by Mitsui Petrochemical Industries, Ltd.] such as Tafmer PO280, Tafmer PO480, Tafmer PO680, and Tafmer posso]. .

The above carboxyl group-containing olefin copolymer has α, β
-Unsaturated caldicic acid comonomer It is produced by direct copolymerization with the above-mentioned olefins or graft copolymerization with polyolefins and polyolefin copolymers.

Examples of the acid component used here include acrylic acid, methacrylic acid, methacrylic acid, itaconic acid, (anhydrous) maleic acid, fumaric acid, and monoesters of the above-mentioned calgenic acids. Preferably, acrylic acid, methacrylic acid, etc. as well as(
anhydrous) maleic acid. Among these, maleic acid (anhydride) is particularly preferred since it can provide a sufficient acid modification effect even with the addition of fewer ridges than other acids. Suitable carboxyl group-containing olefin copolymers include ethylene-butene-1-(anhydrous) maleic acid copolymer, ethylene-propylene-(anhydrous) maleic acid copolymer, and the like.

Epoxy group-containing olefin copolymers are α,β-unsaturated cal? It is produced by a method such as direct copolymerization of glycidyl ester of phosphoric acid and the above-mentioned olefin, or graft copolymerization with a polyolefin and polyonefin copolymer.

One or more mixtures of α,β-unsaturated carboxyl acids (wherein R is a hydrogen atom or a lower alkyl group), such as glycidyl acrylate, methacrylate, Examples include glycidyl acid and glycidyl ethacrylate, among which glycidyl methacrylate is preferably used.

Such a carphokyfur group- and/or epoxy group-modified polyolefin resin preferably contains monomers having these functional groups in an amount of 0.01 to 20% by weight, particularly 0.05 to 5% by weight.

The polyurethane resin composition of the present invention contains a small amount of a mold release agent,
Additives such as a coupling agent, a coloring agent, a lubricant, a weathering stabilizer, a foaming agent, a rust preventive agent, an opacifying agent, a fungicide, and a filler may be added. In the present invention, the addition of a filler is particularly important from the viewpoint of preventing stickiness. Examples of the filler include powders such as calcium carbonate, clay alumina powder, crushed stone powder, talc, barium sulfate, silica, powder mica, and rust powder, with calcium carbonate being particularly preferred.

Since the resin composition of the present invention has excellent flexibility and tactile feel, it is used in the form of films, sheets, and molded articles that come into contact with human skin, and is preferably used in the form of films and sheets. It is particularly useful as a stretch film for products that often come into contact with people, and is used, for example, in the waist and groin areas of body fluid treatment products such as disposable diapers. The thickness of the film is preferably between 10 and 200 microns, and the thickness of the sheet is greater than 200 microns. These films and sheets are manufactured by conventional methods such as extrusion, T-die, and in-striping.

In carrying out the present invention, other thermoplastic resins or elastomers, such as polyvinyl chloride, ethylene-ff [vinyl copolymer, polyester copolymer, styrene elastomer, polybutadiene, PVC elastomer Acrylic polymer
It is also possible to use diamide, polyimide, polyamideimide, polyphenylene sulfide, etc. in combination.

The thermoplastic resin composition of the present invention can be prepared by various known methods. For example, after the raw materials have been mixed uniformly using a tumbler or Henschel mixer, -
There is a method in which the mixture is fed into a screw or twin screw extruder, melted and kneaded, and then prepared as pellets.

(Effect) The essential components constituting the present invention are a polyurethane resin and a modified olefin resin, and as the amount of the olefin copolymer added increases, flexibility, texture, and suppleness improve, but heat resistance and Since permanent deformation tends to decrease, it is useful to appropriately determine the amount added depending on the purpose. Further, if the amount added is less than 1 part by weight, the effect of the present invention is small and it is difficult to achieve non-invention.

The polyurethane resin composition of the present invention obtained in this way has modified r IJ which has excellent compatibility with polyurethane resin.
Because olefin resin is mixed, tensile strength, elongation,
Cold resistance, l1lIt, 1! The polyurethane of the present invention is a composition that has flexibility, softness, and texture without losing the characteristics of urethane resins, such as excellent wear resistance, and has no stickiness during molding or film winding. The film obtained by molding the resin composition has extremely high practicality as an elastic film for waist gather legs and diapers of disposable diapers.

(Examples) The present invention will be specifically explained below with reference to Examples, but the present invention is not limited only to these Examples.

In addition, parts in the examples mean parts by weight.

Reference Example 1 (Production of carboxyl group-containing olefin copolymer) Ethylene-butene-1 copolymer (Tafmer A4090
) 100 parts, 1,3-bis(tart-
0.5 parts of (oxypropyl)benzene and 1 part of maleic anhydride were mixed uniformly. Then cylinder temperature 220
The mixture was kneaded in an extruder set at ℃ and pelletized to obtain a carboxyl group-containing olefin copolymer. When the amount of maleic anhydride nograft was measured using an infrared suction unit,
It was confirmed that this olefin copolymer had 0.75 parts of maleic anhydride grafted to 100 parts of the ethylene-butene-1 copolymer. This is copolymer (I)
It is called.

Reference Example 2 (Production of epoxy group-containing olefin copolymer) Ethylene-butene-1 copolymer (Tafmer A4090)
100 parts of dicumyl oxide, 0.5 part of dicumyl oxide, and 2 parts of methacrylic acid glycidyl ether were uniformly mixed. Next, the mixture was kneaded using a twin-screw extruder set at a cylinder temperature of 200° C., and pelletized to obtain an epoxy group-containing olefin copolymer.

The amount of grafted glycidyl ether of methacrylate was measured using a hydrochloric acid-methyl ethyl ketone solution.

It was found that this olefin copolymer had 1.25 parts by weight of methacrylic acid glycidyl ether grafted to 100 parts of the ethylene-butene-1 copolymer. This is called copolymer (n).

Examples 1 to 6 Thermoplastic polyurethane resin [manufactured by Inu Nippon Ink Chemical Co., Ltd., P
ANDEX T-5167, and PANDEX T-6
Table 1 shows the copolymer (I) obtained in Reference Example 1, the copolymer (n) obtained in Reference Example 2, a small amount of calcium carbonate as a filler, and fatty acid amide as a lubricant. The mixture blended in the ratio shown in 1 was kneaded at 190 to 200°C using a 50 ml extruder to form a left.

The film was molded into a film with a thickness of 30 to 40 μm using an ink V-slit extruder (65i) to form a test piece.

The test results are shown in Table 1.

Comparative Examples 1 to 3 As comparative examples, a mixture of thermoplastic polyurethane resin (PANDEX T-5167 manufactured by Dainippon Ink Chemical Co., Ltd.) and an SBR resin (T-R2000 manufactured by Nippon Gosei Co., Ltd.) and a mixture of each of them individually Evaluations similar to those in Examples were performed. The results are summarized in Table 1.

*1 Evaluation criteria: ◎ Pickling method, ○ Good, Δ Slightly poor, X Poor *2 〃: ◎ None, ○ Slightly, Δ Slightly, X
Remarkable flexibility of film: We investigated the flexibility of film when rolled.

Film texture: The texture of the film was examined.

Occurrence of film wrinkles: The degree of wrinkles remaining when the film was grasped and returned to its original position was examined by touch.

Agent Patent Attorney Katsutoshi Takahashi

Claims (10)

[Claims] (1) A thermoplastic polyurethane resin composition comprising (A) a thermoplastic polyurethane resin and (B) a modified polyolefin resin. (2) The thermoplastic polyurethane resin has a hardness (JIS) of 8
2. The thermoplastic polyurethane resin composition according to claim 1, which has physical properties of 0 to 100%, tensile strength of 200 kg/cm2 or more, and elongation at break of 300% or more. (3) The thermoplastic polyurethane resin composition according to claim 1, wherein the modified polyolefin resin comprises an olefin copolymer containing a carboxyl group and/or an epoxy group. (4) Blending ratio is thermoplastic polyurethane resin (A)
99 to 50 parts, modified polyolefin resin (B) 1 to 5 parts
The thermoplastic polyurethane resin composition according to claim 1, which contains 0 parts (weight ratio). (5) The thermoplastic polyurethane resin composition according to claim 1, wherein the modified polyolefin resin is a modified ethylene/propylene copolymer. (6) The thermoplastic polyurethane resin composition according to claim 1, comprising a filler. (7) The thermoplastic polyurethane resin composition according to claim 6, wherein the filler is calcium carbonate. (8) A film or sheet comprising the thermoplastic polyurethane resin composition according to claim 1. (9) A body fluid treatment article using the film or sheet according to claim 8. (10) Claim 9, wherein the liquid treatment product is a diaper.