JPH05140246A - Modification of polycaprolactone - Google Patents

Abstract

PURPOSE:To improve the mechanical properties, heat resistance and moldability of polycaprolactone to use the same for molding an agricultural film, a material for civil engineering and construction, a fiber, a wire coating material, a mechanical part, an electronic component and an automobile part, for which the conventional polycaprolactone has not been available. CONSTITUTION:0.01-1 pt.wt. alpha,beta-unsaturated carboxylic acid or an anhydride thereof and 0.01-1.0 pt.wt. organic peroxide are compounded with 100 pts.wt. resin component comprised of 30-95 pts.wt. polycaprolactone and 70-5 pts.wt. polyolefin, and kneaded at a temperature which is not lower than the melting point of the polyolefin and not lower than a temperature 20 deg.C lower than the 1-min half-life temperature of the organic peroxide to modify the polycaprolactone, thereby obtaining an acid-modified polyolefin/polycaprolactone blend. Various moldings are obtained from this blend.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for modifying polycaprolactone. More specifically, the present invention relates to a method for modifying polycaprolactone while maintaining microbial disintegration of polycaprolactone, wherein the polycaprolactone is a packaging material, a fiber, an agricultural material, a civil engineering building material,
It is preferably used as a molding material for various parts. Therefore, the present invention also relates to a kneaded product obtained by the above-mentioned modification method and a molded article obtained from the kneaded product.

[0002]

2. Description of the Related Art Polycaprolactone is a thermoplastic polymer obtained by a ring-opening polymerization reaction of .epsilon.-caprolactone, and it takes advantage of its low crystal melting temperature of 60 DEG C. for orthopedic casting, Gibbs material, investment casting method. Disappearance model used in precision casting such as lost wax casting method, heat fusion type temporary adhesive cloth, plastic clay, dental impression collection tray, mold release agent, pigment dispersant, surgical monofilament suture, etc. Used for
Further, since it is biodegradable, it is used as a film, fiber, or other molded article that disintegrates in soil for environmental beautification and protection.

However, the crystal melting temperature of polycaprolactone is extremely low at 60 ° C., and it is very difficult to perform the forming process, especially the tubular film forming process by the inflation method due to the rapid decrease in the melt tension above the crystal melting temperature. Also, while polycaprolactone has fairly high tensile strength and toughness, it is still insufficient.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the properties of polycaprolactone so that it can be used in industrial fields where polycaprolactone has never been used. More specifically, without deteriorating the microbial disintegration property of polycaprolactone, it can be used in a higher temperature region by increasing its crystal melting temperature, that is, it imparts heat resistance, and is also rapidly melted above its crystal melting temperature. As various packaging materials and industrial materials, by not lowering the tension, facilitating molding at high temperature and further improving its mechanical strength so as not to break even in high load areas and high load areas. It is an object of the present invention to provide a useful plastic.

[0005]

Means for Solving the Problems The present inventors have tried to modify polycaprolactone by blending various plastics, and found that a polyolefin resin exhibits a certain effect. However, it is not enough to simply blend a polyolefin resin with polycaprolactone, and when the cause of this was examined, there was a problem with the compatibility of the two and both formed islands in the resin composition. The present invention has been completed based on the idea that the problems of the present invention can be solved if the two are uniformly fused.

That is, the present invention relates to polycaprolactone 3
0.1 to 1 part by weight of an α, β-unsaturated carboxylic acid or its anhydride and 0.01 to 100 parts by weight of an organic peroxide based on 100 parts by weight of a resin component consisting of 0 to 95 parts by weight and 70 to 5 parts by weight of a polyolefin. The present invention relates to a method for modifying polycaprolactone, which comprises blending 1 part by weight to 1.0 part by weight and kneading the mixture at a temperature not lower than the melting point of the polyolefin and 20 ° C. lower than the 1-minute half-life temperature of the organic peroxide.

The present invention also relates to an acid-modified polyolefin-polycaprolactone kneaded product produced by the above-mentioned modification method and a molded article produced from the acid-modified polyolefin-polycaprolactone kneaded product.

The polycaprolactone used in the present invention means ε-caprolactone and ethylene glycol,
It is obtained by reacting with a diol such as diethylene glycol in the presence of a catalyst. The catalyst used in this reaction is generally an organotin compound, an organotitanium compound, or an organotin halide compound.
m, and polymerized at 100 to 230 ° C., preferably in an inert gas, to obtain a polycaprolactone resin usable in the present invention. This production method is described, for example, in Japanese Patent Publication No. 35-189, Japanese Patent Publication No. 35-497, Japanese Patent Publication No. 40-23917, Japanese Patent Publication No. 40-25557, Japanese Patent Publication No. 43-2473, Japanese Patent Publication No. 47-14739, and Japanese Patent Laid-Open No. 56739. No. 49728 and Japanese Patent Laid-Open No. 58-611119.

The polyolefin used in the present invention means high-pressure polyethylene, linear low-density polyethylene,
Ethylene-α-olefin copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-vinyl alcohol copolymer, ethylene-
It means a carbon monoxide-based copolymer, an ionomer, a high-density polyethylene, a medium-density polyethylene, polypropylene, a polypropylene-α-olefin copolymer and the like.

In the present invention, polycaprolactone 30
Approximately 95 parts by weight of polyolefin is added in an amount of 70 to 5 parts by weight. When the amount of polycaprolactone is 30 parts by weight or less, the period required for microbial disintegration of the obtained product is long, and when it is 95 parts by weight or more, that is, polyolefin is 5 parts by weight or less, heat resistance, moldability, mechanical properties Is not desirable because it does not exert the effect of improving the physical properties.

In the present invention, the α, β-unsaturated carboxylic acid means acrylic acid, methacrylic acid, methylmethacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, hymic acid and the like. What is an anhydride?
Maleic anhydride, citraconic anhydride, itaconic anhydride,
Examples thereof include phenyl maleic anhydride, maleic anhydride bromide, and chloromaleic anhydride.

The amount of the α, β-unsaturated carboxylic acid or its anhydride used is 0.1 to 1 part by weight based on 100 parts by weight of the resin component. If the amount is 0.1 parts by weight or less,
The modification effect by these acid compounds is not sufficient, the improvement effect of mechanical strength, heat resistance, molding processability is not sufficiently exerted, and the improvement effect reaches a saturation point even if 1 part by weight or more is used,
It is not economical and is not desirable.

Examples of the organic peroxides used in the present invention include the followings.
The value in parentheses indicates a one-minute half-life temperature]: tert-butylperoxyisopropyl carbonate (135), tert-butylperoxylaurate (140), 2,5-dimethyl-2,5-di (benzoylperoxy) Hexane (140), tertiary butyl peroxyacetate (14
0), di-tert-butyl diperoxyphthalate (14
0), tert-butylperoxymaleic acid (140), cyclohexanone peroxide (145), tert-butylperoxybenzoate (145), dicumyl peroxide (150), 2,5-dimethyl-2,5-di (tert-butyl) Peroxy) hexane (155), tert-butyl cumyl peroxide (155), tert-butyl hydroperoxide (158), di-tert-butyl peroxide (16)
0), 2,5-dimethyl-2,5-di (tert-butylperoxy) hexyne-3 (170), di-isopropylbenzene hydroperoxide (170), p-menthane hydroperoxide (180), 2,5-. Dimethylhexane-2,5-dihydroperoxide (213).

The organic peroxide has a function of grafting α, β-unsaturated carboxylic acid or its anhydride onto the basic skeleton of the resin and a function of grafting polycaprolactone and a part of the polyolefin. The amount of the organic peroxide used is 0.
If it is 0.01 to 1 part by weight, the amount of the grafted portion will be small and the modifying effect will not be exhibited if it is 0.01 part by weight or less, and if it is 1.0 part by weight or more, an excessive crosslinking reaction will occur and gel or lumps will be formed. This is not desirable because not only the quality of the molded product is deteriorated but also the molding processability is deteriorated due to excessive crosslinking.

The resin composition of the present invention has a microbial disintegrating property,
Pigments, cross-linking agents, lubricants, processability improvers, antistatic agents, nucleating agents, antifog agents, flame retardants, antibacterial agents, deodorants, if desired, as long as heat resistance, mechanical properties and molding processability are not impaired. It is also possible to add agents, fragrances, freshness-retaining agents, infrared emitting agents, heat stabilizers, inorganic fillers, antioxidants, ultraviolet absorbers and the like.

The modification of the polycaprolactone of the present invention is carried out by using a Banbury mixer, a pressure kneader, a twin-screw extruder, a Busco kneader, etc., for the resin component, α, β-unsaturated carboxylic acid or its anhydride and organic peroxide. It is carried out by heating and kneading while applying shear stress at a melting point of the polyolefin or higher and a temperature of 20 ° C. lower than the one-minute half-life temperature of the organic peroxide. By heat kneading, α, β-unsaturated carboxylic acid or its anhydride is grafted onto polycaprolactone or polyolefin, and a graft reaction between polycaprolactone and polyolefin also occurs to form an acid-modified polyolefin-polycaprolactone kneaded product.

The production of various molded articles from the above kneaded product is carried out by known methods such as inflation method, injection molding method, calender method, compression molding method, hollow molding method, powder molding method, extrusion molding method and vacuum molding method. .. Examples of the molded article include, but are not limited to, packaging films, fibers, agricultural films, civil engineering and construction materials, electric wire coating materials, machine parts, electronic parts, automobile parts, and the like.

[0018]

According to the present invention, as described above, a specific amount of polyolefin, α, β-unsaturated carboxylic acid or its anhydride and organic peroxide is blended with polycaprolactone, and the mixture is heated and kneaded at a specific temperature to improve polycaprolactone. As compared with the case where only the polyolefin is kneaded with the polycaprolactone, the compatibility between the polycaprolactone and the polyolefin is increased, and not only the modification effect by the polyolefin is further improved, but also α, β-unsaturated carboxylic acid or By acid modification with the anhydride and grafting with an organic peroxide, the mechanical properties, heat resistance and molding processability of polycaprolactone can be further improved.

[0019]

EXAMPLES Next, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples, and those embodying the technical idea of the present invention are within the scope of the present invention. Contained within. Example 1 60 parts by weight of polycaprolactone (trade name: TONE P-767, degree of polymerization: 400, melt index: 30 g / 10 minutes, density: 1.15 g / cc, manufactured by Union Carbide Chemicals & Plastics, USA), ethylene- Carbon monoxide copolymer (trade name DHDA-1219,
Melt index 0.8g / 10min, density 0.935
g / cc, manufactured by Union Carbide Chemicals & Plastics, USA) 40 parts by weight, maleic anhydride 0.5 parts by weight, 2,5-dimethyl-2,5-di (tertiary butylperoxy) hexyne-3. 0.2 part by weight and 0.02 part by weight of an antioxidant (trade name Irganox 1010) are mixed in a Henschel mixer at room temperature, and then kneaded with a Banbury mixer at 150 ° C. for 15 minutes to give 1 mixture.
The mixture was extruded at 80 ° C. with an extruder to obtain a pelletized acid-modified polyolefin-polycaprolactone kneaded product. The pellets are heated in a hot press machine at 180 ° C and 100 kg / c.
A sheet having a thickness of 1 mm was formed by heating and pressing at m ² , and the tensile strength and elongation of the sheet were measured according to JIS-K6760.

Comparative Example 1-1 The same experiment as in Example 1 was carried out except that maleic anhydride and organic peroxide were not used at all, pellets and a sheet with a thickness of 1 mm were prepared, and the tensile strength and The elongation was measured.

Comparative Example 1-2 80 in a hot press molding machine using only polycaprolactone
A sheet having a thickness of 1 mm was formed in the same manner as in Example 1 by heating and pressing at 100 ° C. and 100 kg / cm ² , and the tensile strength and elongation of the sheet were measured. The results of Example 1, Comparative Example 1-1 and Comparative Example 1-2 are summarized in Table 1.

[0022]

[Table 1]

Example 2 Instead of the ethylene-carbon monoxide copolymer used in Example 1, a linear ethylene-butene-1 copolymer (trade name GM) was used.
The same experiment as in Example 1 was carried out except that L-2420, melt index 20 g / 10 min, density 0.924 g / cc, manufactured by Nippon Unicar Co., Ltd. was used.

Comparative Example 2-1 The same experiment as in Example 2 was carried out except that maleic anhydride and organic peroxide were not used at all in Example 2.

Comparative Example 2-2 The same experiment as in Example 1-2 was conducted. The results of Example 2, Comparative Example 2-1 and Comparative Example 2-2 are summarized in Table 2.

[0026]

[Table 2]

Example 3 In place of the ethylene-carbon monoxide copolymer used in Example 1, a high-pressure process ethylene-ethyl acrylate copolymer (trade name: DPDJ-9169, melt index: 20 g / 1) was used.
The same experiment as in Example 1 was performed except that 0 minutes, density 0.931 g / cc, manufactured by Nippon Unicar Co., Ltd. was used.

Comparative Example 3-1 The same experiment as in Example 3 was conducted except that maleic anhydride and organic peroxide were not used at all in Example 3.

Comparative Example 3-2 The same experiment as in Example 1-2 was conducted. Table 3 shows the results of Example 3, Comparative Example 3-1, and Comparative Example 3-2.

[0030]

[Table 3]

Example 4 The same experiment as in Example 1 was carried out except that the amounts of polycaprolactone and ethylene-carbon monoxide copolymer in Example 1 were changed to 30 parts by weight and 70 parts by weight, respectively. ..

Comparative Example 4-1 The same experiment as in Example 4 was conducted except that maleic anhydride and organic peroxide were not used at all in Example 4.

Comparative Example 4-2 The same experiment as in Example 1-2 was conducted. The results of Example 4, Comparative Example 4-1 and Comparative Example 4-2 are collectively shown in Table 4.

[0034]

[Table 4]

Example 5 The same experiment as in Example 1 was carried out except that the amounts of polycaprolactone and ethylene-carbon monoxide copolymer in Example 1 were changed to 95 parts by weight and 5 parts by weight, respectively. ..

Comparative Example 5-1 The same experiment as in Example 5 was carried out except that maleic anhydride and organic peroxide were not used in Example 5.

Comparative Example 5-2 The same experiment as in Example 1-2 was conducted. The results of Example 5, Comparative Example 5-1 and Comparative Example 5-2 are collectively shown in Table 5.

[0038]

[Table 5]

[0039]

As described in detail above, the method for modifying polycaprolactone of the present invention can provide the mechanical properties, heat resistance and molding processability of polycaprolactone without losing the microbial disintegration property of polycaprolactone. It is possible to provide an acid-modified polyolefin-polycaprolactone kneaded product in which the above is remarkably improved. Therefore, the kneaded product is
New industrial fields where polycaprolactone could not be applied so far, such as agricultural films, civil construction materials,
It can be used as a molding material for fibers, wire coating materials, machine parts, electronic parts, automobile parts, etc.

Claims (3)

[Claims] 1. A resin component 100 comprising 30 to 95 parts by weight of polycaprolactone and 70 to 5 parts by weight of polyolefin.
With respect to parts by weight, 0.1 to 1 part by weight of α, β-unsaturated carboxylic acid or its anhydride and 0.01 to 100 parts of organic peroxide are used.
A method for modifying polycaprolactone, which comprises mixing 1.0 part by weight and kneading by heating at a melting point of the polyolefin or higher and a temperature 20 ° C. lower than the one-minute half-life temperature of the organic peroxide. 2. An acid-modified polyolefin-polycaprolactone kneaded product produced by the modifying method according to claim 1. 3. The acid-modified polyolefin according to claim 2.
A molded product manufactured from a kneaded product of polycaprolactone.