JPH03207757A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To obtain a composition suitable as an improving material for various kinds of plastics, material for the sole of footgear, etc., having excellent heat resistance, oil resistance, mechanical strength, etc., by blending specific amounts of polyurethane-based thermoplastic elastomer and unsaturated nitrile-conjugated diene-based copolymer rubber. CONSTITUTION:(A) 2-98wt.% polyurethane-based thermoplastic elastomer is blended with (B) 2-98wt.% copolymer rubber selected from unsaturated nitrile- conjugated diene-based copolymer rubber (e.g. acrylonitrile-butadiene rubber) and unsaturated nitrile-conjugated diene-based copolymer rubber (hydrogenated substance) containing one or more functional groups selected from epoxy group, hydroxyl group, amino acid and carboxyl group.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a highly compatible polymer blend thermoplastic elastomer composition with excellent heat resistance, oil resistance, mechanical strength, and abrasion resistance7. More specifically, the present invention relates to a thermoplastic composition comprising a polyurethane thermoplastic elastomer (TPU) and an unsaturated nitrile-conjugated diene copolymer rubber.

[Conventional technology] TPU has excellent tensile strength, tear strength, abrasion resistance, oil resistance, and bending fatigue resistance, and is used for sports shoe soles, ski boots,
It is widely used for various hoses, tubes, films, etc. However, it has disadvantages such as poor moldability such as water resistance and narrow optimum processing temperature range, and high density and high water absorption.

Furthermore, this type of thermoplastic elastomer is a multi-block copolymer composed of a soft segment of polyether or polyester, a hard segment of polyurethane consisting of an aromatic diisocyanate, and a short chain diol such as ethylene glycol or 1,4-butanediol. is a polymer, T
In order to exhibit the above-mentioned excellent properties of PU, it is necessary to contain a certain amount of hard segments. Therefore, a high-performance TPU material has to be a material with high hardness and high elastic modulus, and at present, TPU with low hardness and low elastic modulus that maintains high performance has not been obtained.

For this purpose, compositions have been proposed in which TPU is blended with hydrocarbon polymers such as vinyl aromatic compound-conjugated diene compound block copolymers (for example,
2-295954). However, polar-nonpolar polymer blend systems have poor compatibility, and the performance of the blends has not always been satisfactory. In addition, the vinyl aromatic compound-conjugated diene compound block copolymer has problems in weather resistance and heat resistance, and cannot take full advantage of the characteristics of high-performance TPU.

[Problems to be Solved by the Invention] As a result of intensive studies to solve the above-mentioned drawbacks, the present invention
An unsaturated nitrile-conjugated diene copolymer rubber having at least one functional group selected from an epoxy group, a hydroxyl group, an amino group, and a carboxyl group in U, and A thermoplastic elastomer blended with at least one copolymer rubber selected from these hydrogenated polymers can achieve low hardness and low elastic modulus without losing the excellent properties of TPU, It was discovered that a polymer blend with excellent compatibility and improved oil resistance and processability that could not be obtained with conventional low hardness TPU or TPU compositions was formed, and based on this knowledge, the present invention was completed. It's arrived.

[Means for solving the problems] That is, the present invention comprises (A) 2 to 98% by weight of TPU, and (
B) unsaturated nitrile-conjugated diene copolymer rubber, unsaturated nitrile-conjugated diene copolymer rubber having at least one functional group selected from epoxy group, hydroxyl group, amino group and carboxyl group; The present invention provides a thermoplastic elastomer composition comprising 2 to 98% by weight of at least one copolymer rubber selected from these hydrogenated polymers.

(A) TPU used in the present invention is a polymer obtained by polyaddition reaction using linear polyol short chain glycol, diisocyanate, etc. as raw materials through urethane bonds in the molecule, and is a polymer obtained from shoe soles, It is used in hoses, tubes, adhesives, etc. The long chain polyol that is the raw material for this thermoplastic polyurethane elastomer contains (1
, 4-butylene adipate), poly(1,6-hexane adipate), polycaprolactone, polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol, and the like. In addition, short chain glycols include ethylene glycol, 1,4-butanediol,
1,6-hexanediol, etc., and diisocyanates include tolylene diisocyaner), 4.4
'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, and the like. A soft segment is formed by a long chain polyol and a diisocyanate, and a hard segment is formed by a short chain glycol and a diisocyanate.

The preferred molecular weight of the thermoplastic polyurethane elastomer is preferably 5,000 to 500,000, more preferably 10,000 to 300,000.

The unsaturated nitrile-conjugated diene copolymer rubber (B) used in the present invention refers to unsaturated nitriles such as acrylonitrile and methacrylonitrile, conjugated dienes such as 1゜3-butadiene and isoprene, and optionally these. It is a copolymer with acrylic acid alkyl esters such as methyl acrylate, ethyl acrylate, and n-butyl acrylate. Among these, acrylonitrile-butadiene rubber is particularly preferred.

The composition of each component of the present invention includes 2 to 98% by weight of TPU, unsaturated nitrile-conjugated diene copolymer rubber, and/or at least one functional group selected from epoxy groups, hydroxyl groups, amino groups, and carboxyl groups. 2 to 98% by weight of unsaturated nitrile-conjugated diene copolymer rubber having 3 to 95% by weight of an unsaturated nitrile-conjugated diene copolymer rubber having at least one functional group selected from groups and carboxyl groups.

If TPU is less than 2% by weight, heat resistance and mechanical strength will be poor, and if TPU is more than 98% by weight, oil resistance will be insufficient and a composition with low hardness and low modulus of elasticity will not be obtained.

In addition, (B) the functional unsaturated nitrile-conjugated diene copolymer rubber used in the present invention has the following epoxy group,
It can be obtained by copolymerizing a functional monomer selected from the group of monomer compounds having a hydroxyl group and an amino group.

■ Glycidyl acrylate, glycidyl methacrylate, glycidyl vinyl ether, glycidyl allyl ether, etc.

■ Hydroxyethyl acrylate, hydroxymethacrylate, hydroxypropyl acrylate, etc.

■ Dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dipropylaminoethyl acrylate, dipropylaminoethyl methacrylate, dibutylaminoethyl acrylate, dibutylaminoethyl methacrylate, diethylaminopropyl methacrylate, ethylaminoethyl methacrylate, etc. .

Further, examples of the carboxyl group-containing monomer constituting the carboxyl group-modified unsaturated nitrile-butadiene rubber used in the present invention include acrylic acid and/or methacrylic acid.

Its content (hereinafter sometimes referred to as "carboxyl group content") is 2.0 to 6.0 mol%, preferably 3.0 mol% in the carboxyl group-modified unsaturated nitrile-butadiene rubber.
~5.0 mol%.

In the present invention, in addition to the above-mentioned unsaturated nitrile-conjugated diene copolymers and/or copolymers of these and functional monomers, hydrogenated products (polymers) of these can also be used.

In addition, other thermoplastic resins or elastomers, such as polystyrene resins, polyethylene resins, polypropylene resins, diene resins, polyvinyl chloride resins, and polyvinyl acetate resins, may be used as necessary, without departing from the purpose of the present invention. , polycarbonate resin, polyacetal resin, polyamide resin, polyester resin, polyether resin, polysulfone, thermoplastic resin such as polyphenylene sulfide, styrene-butadiene block copolymer, styrene-isoprene block copolymer and thermoplastic elastomers such as styrene-based thermoplastic elastomers, polyolefin-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and vinyl chloride-based thermoplastic elastomers, such as hydrogenated products of these, styrene-butadiene rubber, butadiene rubber, Acrylic rubber elastomers can be mixed and used.

Furthermore, the composition of the present invention may contain crosslinks such as sulfur crosslinks, peroxide crosslinks, resin crosslinks, metal ion crosslinks, electron beam crosslinks, and silane crosslinks, and these crosslinks may be static or dynamic. It can be done in a certain way.

The composition of the present invention does not particularly require a compatibilizer because the components (A) and (B) are compatible, but a compatibilizer may be added if necessary.

Furthermore, additives used for ordinary thermoplastic resin elastomers and thermoplastic elastomers can be added to the thermoplastic elastomer composition of the present invention, if necessary. For example, plasticizers such as phthalate compounds, fillers or reinforcing agents such as silica, talc, glass fibers,
Other additives include antioxidants, ultraviolet absorbers, antistatic agents, flame retardants, lubricants, foaming agents, colorants, pigments, core materials, crosslinking agents, crosslinking aids, and mixtures thereof.

Various known methods can be applied to prepare the composition of the present invention. For example, any conventionally known method may be used, such as an extruder (single-screw, two-wheel), roll, Banbury mixer, kneader, Henschel mixer, etc.

In addition, the thermoplastic elastomer composition obtained by the above method can be molded using conventionally known methods such as extrusion molding,
It can be processed into practically useful molded products by injection molding, blow molding, compression molding, calendering, etc. Also painted, if necessary.

Processing such as plating can also be applied.

The thermoplastic elastomer composition of the present invention has excellent heat resistance, abrasion resistance, processability, flexibility, low temperature properties, temperature dependence, compatibility, paintability, printability, hot stampability, adhesiveness, and deep drawability. By taking advantage of its properties such as elasticity, hot water resistance, rubber elasticity, rubber feel, flexibility, slip resistance, and stress crack resistance, it is used as a variety of plastic improvement materials, footwear sole materials, adhesive and viscosity agent materials, and asphalt modification materials. It can be used as a modification material for vulcanized rubber. For example, sheet applications such as meat and fresh fish trays, fruit and vegetable bags, frozen dessert food containers, food packaging, daily necessities packaging, industrial material packaging, film applications such as elastic tapes for disposable diapers, sports shoes, leisure shoes, fashion sandals, etc. Footwear applications such as leather shoes, home appliance applications such as televisions, stereos, and vacuum cleaners, automotive interior and exterior parts applications such as bumper parts, body panels, and site shields, hot melt adhesives and adhesives, and contact adhesives. It can be used in a wide range of applications, including materials such as spray adhesives, asphalt blend materials such as road paving materials, waterproof sheets, and pipe coatings, and other daily necessities, leisure products, toys, and industrial products.

[Examples] Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the Examples unless the gist of the present invention is exceeded.

The acrylonitrile-butadiene copolymer rubber (NBR) used in Examples and Comparative Examples is as follows.

NBR-(1): JSRN210S manufactured by Japan Synthetic Rubber Building
(30% bound acrylonitrile) NBR-(2): JSRN202S manufactured by Japan Synthetic Rubber ■
(40% bound acrylonitrile) NBR-(31: JARN215S manufactured by Japan Synthetic Rubber ■
L.

(48% bound acrylonitrile) NBR-U): JSRN250S (made by Japan Synthetic Rubber)
(Bound acrylonitrile 20%) Furthermore, an acrylonitrile-butadiene copolymer rubber containing a carboxyl group is produced by the following method.

Emulsion polymerization was carried out at a temperature of 30°C using the monomers and polymerization agents shown below in an autoclave with an internal volume of 2ON.

Parts by weight Butadiene 34 Acrylonitrile 59 Methacrylic acid 7 Water
220 Sodium dodecylbenzenesulfonate 4 Tertiary dodecyl mercaptan 0.55 Potassium persulfate
0.27 Cyanoethylated diethanolamine 0.1
Potassium pentahydroxide 0.10 0.10 per 100 parts by weight of monomer when the polymerization rate reaches 85%.
The polymerization reaction was stopped by adding 2 parts by weight of hydroxylamine.

Next, the produced latix was heated, and after removing unreacted monomers by steam distillation, 1 part of an antiaging agent (alkylated phenol) was added per 100 parts by weight of the produced copolymer, and a calcium chloride aqueous solution was added. It was used to coagulate and form a crumb.

After washing the generated crumb with water, it was dried at 100° C. in a hot air dryer to obtain a sample (copolymer a).

When the composition of the produced copolymer a was measured using a Coleman nitrogen analyzer, the total nitrogen content was 9.20% by weight, so the acrylonitrile content of the copolymer was 3.
It was calculated to be 4.2 mol%.

Next, 1 g of copolymer a was accurately weighed, dissolved in 100 ml of pyridine, and neutralized with 0.5N alcoholic potassium hydroxide solution using phenolphthalein as an indicator.
I did this.

The methacrylic acid content of copolymer a was calculated according to the following formula, and was found to be 6.5% by weight.

V: Alcoholic water potassium solution required for neutralization (m
l) F: Factor of alcoholic potassium hydroxide W: Sample weight (r) From the above, the weight composition (molar composition) of copolymer A is methacrylic acid/acrylonitrile/butadiene straw 6.5/33
/60.5 (4.2/34.2/61.6).

In addition, the Mooney viscosity (ML
, 100°C) was 59.

Copolymerization was carried out using the same formulation as for 1+4 copolymer a, with the monomer composition changed as shown in Table 1, to obtain various copolymers.

The compositions and Mooney viscosities of the various copolymers obtained are shown in Table 1.

Furthermore, a GMA-modified acrylonitrile-butadiene copolymer was obtained by using glycidyl acrylate in the composition shown in Table 1 instead of methacrylic acid. Table 1 shows the composition and Mooney viscosity of the obtained copolymer.

Moreover, hydrogenated acrylonitrile-butadiene copolymer rubber is manufactured by the following method.

Cu acetate used as a promoter was dissolved in a solution of NBR-(1) in tetrahydrofuran, and the system containing the Pd supported catalyst was purged with nitrogen, and then heated at 50 kg/c with hydrogen.
The hydrogenation reaction was carried out at 60° C. for 6 hours.

Furthermore, a hydrogenation reaction was also performed on N11La using the same manufacturing method to obtain a hydrogenated polymer.

<Evaluation method of physical properties> Tensile properties: Based on JIS K630I, 50% tensile stress (M5
o), 100% tensile stress (Mloo), 3°0% tensile stress (M3oo), tensile strength (TB), elongation at break (E8)
I asked for

Hardness: Measured using a JIS A hardness meter in accordance with JIS K6301.

density: The value at 23°C was determined by the buoyancy method.

VICAT softening temperature: Measured under a load of 1 kg in accordance with ASTM DIO44.

Taper wear: Measured using a worn wheel H-22 in accordance with ASTM D1044.

Oil resistance: Soaked in ASTM oil at 100℃ for 72 hours,
The volume change rate was determined.

(Examples 1 to 3) Polyurethane thermoplastic elastomer (III Kuraray Co., Ltd., Kuramiron U-3190) and NBR-(1) were heated at 190°C using a blast mill at the composition ratio shown in Table 1.
The mixture was kneaded at 60 rpm for 5 minutes to obtain a blend. The mixed wire was press-molded, compression-molded test pieces were prepared, and various physical properties were measured. The results are shown in Table-2.

(Examples 4 to 5) For 75 weight of polyurethane thermoplastic elastomer,
A blend was prepared in the same manner as in Example 1 using 25 parts by weight of NBR-(2) and NBR-(3), test pieces were prepared, and various physical properties were measured. The results are shown in Table-2.

(Examples 6 to 9) Copolymers NcLa, b, and c in Table 1 were added to 75 parts by weight of polyurethane thermoplastic elastomer.

Evaluation was conducted in the same manner as in Example 1 using 25 parts by weight of each of d. The results are shown in Table-2.

(Example 10) Evaluation was conducted in the same manner as in Example 1 using 25 parts by weight of hydrogenated NBR-(1) with respect to 75 parts by weight of polyurethane thermoplastic elastomer.

The results are shown in Table-2.

(Example 11) Evaluation was conducted in the same manner as in Example 1 using 25 parts by weight of hydrogenated Naa in Table 1 to 75 parts by weight of polyurethane thermoplastic elastomer.

The results are shown in Table-2.

(Example 12) NBR-(
4) Evaluation was conducted in the same manner as in Example 1 using 25 parts by weight. The results are shown in Table-2.

(Comparative Example 1) The polyurethane thermoplastic elastomer used in the present invention was evaluated. The results are shown in Table-2.

Low hardness and low modulus of elasticity are not sufficient, and oil resistance is also poor.

(Comparative Example 2) The same evaluation as in Example 1 was conducted using 99 parts by weight of NBR-(1) with respect to 1 part by weight of the polyurethane thermoplastic elastomer. Due to the small amount of TPU, mechanical strength,
Poor heat resistance and abrasion resistance.

(Comparative Example 3) Styrene-butadiene styrene block copolymer (
The same evaluation as in Example 1 was conducted using 25 parts by weight of SBS. The TPU/SBS blend system is one way to achieve low hardness and low elastic modulus, but the TPU/SBS blend system of the present invention
BR type has better mechanical strength, heat resistance, abrasion resistance,
It can be seen that the oil resistance is excellent.

The following margin [Manufacture of NBR containing hydroxyl groups and amino groups] Each composition of the formulation shown in Table 3 below was subjected to emulsion polymerization at 30°C in an autoclave, and when the polymerization rate reached about 70%, the monomer ( Polymerization was stopped by adding 0.2 part of hydroxydiethylamine per 100 parts of polymerization component. To the thus obtained rubber latex, 2 PHR of alkylated phenol (antiaging agent) was added, coagulated with an aqueous calcium chloride solution, and then washed with water to obtain a polymer a%b.

The following margin [Manufacture of carboxyl group-containing EPM] 1.3 parts by weight for 100 parts by weight of EPM used in Reference Example 1
-0.5 parts by weight of bis(tert-butylperoxypropyl)benzene and 1 part by weight of acrylic acid or methacrylic acid are mixed and kneaded in an extruder set at a cylinder temperature of 220°C to form pellets of carboxyl group-containing EPM. I did this. It was confirmed from the infrared absorption spectrum that 0.8% by weight of acrylic or methacrylic acid was grafted onto EPM.

(Example 13) Similar evaluations were conducted using 25 parts by weight of polymer a shown in Table 3 with respect to 75 parts by weight of polyurethane thermoplastic elastomer. The results are shown in Table 4.

(Example 14) Similar evaluations were conducted using 25 parts by weight of polymer b shown in Table 3 with respect to 75 parts by weight of polyurethane thermoplastic elastomer. The results are shown in Table 4.

(Example 15) Similar evaluations were conducted using 90 parts by weight of NBR-(1) with respect to 10 parts by weight of polyurethane thermoplastic elastomer. The results are shown in Table 4.

(Example 16) Similar evaluations were conducted using 10 parts by weight of NBR,-(I) with respect to 90 parts by weight of polyurethane thermoplastic elastomer. The results are shown in Table 4.

(Comparative Example 4) Carboxy-modified styrene-butadiene styrene block copolymer (shell chemical type KRATON DXi30) was added to 75 parts by weight of polyurethane thermoplastic elastomer.
0) Similar evaluations were conducted using 25 parts by weight. It has better mechanical strength, heat resistance, abrasion resistance, and oil resistance than unmodified SBS, but is inferior to when NBR is used.

(Comparative Example 5) A similar evaluation was conducted using 25 parts by weight of a carboxy-modified ethylene-propylene copolymer with respect to 75 parts by weight of a polyurethane thermoplastic elastomer.

Oil resistance is inferior to when NBR is used.

[Effect of the invention] The polyurethane thermoplastic elastomer composition obtained by the above method maintains the excellent properties of polyurethane thermoplastic elastomers such as high strength, high elongation, high softening temperature, and abrasion resistance, and has low hardness. , a thermoplastic elastomer with low modulus, flexibility and oil resistance is obtained, and is extremely practical.

hand Continued Supplementary Positive 1.Display of the incident 1990 Patent Application No. 2790 2. Name of the invention thermoplastic elastomer composition book (spontaneous) March 12, 1990

Claims (1)

[Claims] (A) 2 to 98% by weight of polyurethane thermoplastic elastomer, (B) unsaturated nitrile-conjugated diene copolymer rubber, and at least one functional group selected from epoxy groups, hydroxyl groups, amino acids, and carboxyl groups. A thermoplastic elastomer composition comprising 2 to 98% by weight of at least one copolymer rubber selected from an unsaturated nitrile-conjugated diene copolymer rubber having the following: and hydrogenated products thereof.