JP2007308638A - Polylactic acid/polyolefin-based composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polylactic acid/polyolefin-based composition, in which stiffness which is a characteristic of a polylactic acid resin is utilized, excellent in impact resistance and having moldability and high mechanical strength. <P>SOLUTION: The polylactic acid/polyolefin-based composition is composed of three components obtained by combination of a polylactic acid resin, a polyolefin resin and a modified polyolefin compound, and the composition comprises 4.5 pts.mass polylactic acid resin, 25-88.75 pts.mass polyolefin resin and 6.75-45 pts.mass modified polyolefin compound, with the proviso that total amount of three components is 100 pts.mass. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a polylactic acid / polyolefin composition used for producing a plastic product such as a film.

  In recent years, various plastic products have been used in enormous amounts in daily life, and problems have arisen from the standpoint of protecting the natural environment, including treatment after use of these plastic products. For example, disposable plastic materials formed by extrusion methods such as packaging trays and shopping bags used in supermarkets, draining nets, pots for seedlings, etc. are routinely used as waste from homes and offices. It has been discharged. Most of these are disposed of by incineration. By the way, most of these use general-purpose plastics derived from fossil resources, mainly polyolefin resins.

Conventionally, these plastic materials have a problem of high calorie burn and damage the incinerator. At the same time, when completely incinerated in recent years, carbon in the substance is released as CO ₂ at a stretch, causing global warming. It is a problem as a factor.

As means for solving this problem, in recent decades, means for reducing calorific value by adding several tens of percent of an inorganic substance such as calcium carbonate to a polyolefin resin have been adopted. However, the fact that the added inorganic substance remains as ash has been regarded as a problem on the contrary in connection with landfill treatment, and further, there is no solution in terms of the generation of CO _2. .

  As a solution, there is a demand for a material that can reduce the amount of heat generated when burned, and that does not leave a large amount of residue as ash after combustion. One of them is a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof, or a polyolefin resin containing a mixture of a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof and an unmodified polyolefin resin, and a starch-based material. A starch-based molding composition has been proposed (Patent Document 1). This polyolefin-starch molding composition is excellent in processability, heat fluidity and photodegradability, and has a mechanical strength sufficient for practical use.

As a countermeasure other than the polyolefin-starch molding composition, a polylactic acid-modified polyolefin resin composition containing a polyolefin resin modified with an unsaturated carboxylic acid or a derivative thereof in a polylactic acid resin has been proposed. (Patent Documents 2 and 3). These polylactic acid-modified polyolefin resin compositions are characterized by excellent strength and impact resistance and biodegradability.
JP-A-6-340771 JP 2001-123055 A JP 9-316310 A

  By the way, when the above-mentioned polyolefin-starch-based composition is used for general film applications, since the starch-based composition is contained in the composition, when it is discarded as waste and incinerated, the calorie reduction during combustion is reduced. Although the problem of ash residue is solved, there are the following problems.

  (1) Due to the influence of the starch system in the composition, there are factors such as “burning”, “odor”, and “gas generation” at the time of molding, so care must be taken in temperature control at the time of molding.

  (2) Even if the temperature control at the time of molding is careful due to the influence of the starch system in the composition, the starch system composition is discolored due to the heat effect at the time of molding, and a transparent film is obtained. I can't.

  (3) Although it is suitable as a collection bag for garbage generated from households and business establishments, it is not suitable for a packaging film for foods that are directly taken into mouth because it contains a starch-based composition.

  On the other hand, the polylactic acid / modified polyolefin resin composition described above can be completely decomposed in a natural environment due to the high content of polylactic acid. Therefore, when it is discarded as garbage after use, landfill disposal can be advantageously used separately from conventional incineration disposal, but there are the following problems.

  (4) The resin component is a two-component structure of polylactic acid and modified polyolefin, and the price of each resin is 2.5 to 10 times the price of the olefin resin, and the price is high. Therefore, it is effective in terms of disposal processing, but includes a factor for increasing the product price.

  (5) Since each resin at the time of molding must be kneaded once in a biaxial extrusion kneader, which is a separate process, melt extruded, formed into a strand and pelletized, the main raw material must be used. It includes factors that increase costs.

  The present invention has been made in consideration of such circumstances, and the molding is performed with the problems (1) to (3) when the molding is performed with the polyolefin / starch-based composition and the polylactic acid / modified polyolefin-based resin composition. Polylactic acid / polyolefin-based composition that overcomes problems (4) and (5), and has excellent impact resistance, moldability, and high mechanical strength, making use of the rigidity characteristic of polylactic acid Is to provide.

  1. The polylactic acid / polyolefin composition of the present invention is composed of three components by a combination of a polylactic acid resin, a polyolefin resin, and a modified polyolefin compound, 4.5-30 parts by mass of the polylactic acid resin, and 25-88. 75 parts by mass, 6.75 to 45 parts by mass of the modified polyolefin compound are contained, and the total amount of the three components is 100 parts by mass.

  2. The polylactic acid / polyolefin-based composition of the present invention is characterized in that, in the above 1, the modified polyolefin compound is contained 1.5 times or more with respect to the polylactic acid resin.

  Further, the polylactic acid / polyolefin composition of the present invention is the above-mentioned 1. Or 2. The polylactic acid resin is characterized in that it is a resin obtained by lactating and polymerizing plant starch.

According to the present invention, a polylactic acid / polyolefin-based composition can be obtained that makes use of the rigidity characteristic of a polylactic acid resin, is excellent in impact resistance, has moldability, and high mechanical strength. Further, lactated polylactic acid resin plant starch, by a resin obtained by polymerization, the generation amount of CO ₂ can be suppressed in a proportion 1.5 to 10%.

Hereinafter, the present invention will be described in more detail.
In the present invention, the polylactic acid resin is a resin obtained by lactating and polymerizing plant starch such as corn, potato, and sweet potato, and its structure is composed only of monomer units derived from L-lactic acid and / or D-lactic acid. Refers to the polymer.

  The production of the polylactic acid resin can be performed by adopting any known polymerization method, and the most typical method is a method of ring-opening polymerization of lactide which is an anhydrous cyclic dimer of lactic acid (lactide method). However, lactic acid may be subjected to direct condensation polymerization.

  When the polylactic acid resin is composed of monomer units derived from L-lactic acid resin and / or D-lactic acid resin, the polymer is crystalline and has a high melting point, and monomer units derived from L-lactic acid resin and D-lactic acid resin By changing the ratio (hereinafter referred to as L / D), the crystallinity and melting point can be freely adjusted. As these polylactic acid resins, for example, trade names: LACEA manufactured by Mitsui Chemical Co., Ltd., Eco Plastics U'z manufactured by Toyota Motor Co., Ltd., and trade names manufactured by Nature Work: Nature Works are commercially available. Any resin may be used in the present invention.

It is essential that the amount of the polylactic acid resin added is 4.5 to 30 parts by mass, and more preferably, it is excellent in sufficient mechanical properties during use and contributes to the CO ₂ reduction effect. 10 to 20 parts by mass. Here, when the addition amount of the polylactic acid resin is less than 4.5 parts by mass, since the content of the olefin resin is large, the mechanical characteristics are sufficiently maintained and the effect of high oxygen permeability is obtained. However, disintegration by microorganisms cannot be imparted, and no reduction effect of burned calories is recognized. Also, the CO ₂ reduction effect is as low as 1.0% or less, which is not preferable. On the other hand, when the addition amount of the polylactic acid resin exceeds 30 parts by mass, the disintegration effect by microorganisms contributes, but a hard and brittle film is obtained, the oxygen permeability is lowered, and the film texture is hard, so At this time, a problem arises that wrinkles or the like occur and stable molding cannot be performed.

  In the present invention, various types of olefin resins can be used. For example, polypropylene, high density polyethylene (hereinafter referred to as HDPE), medium density polyethylene (hereinafter referred to as LLDPE), and low density polyethylene (hereinafter referred to as LDPE). And monoolefin polymers such as polybutene and poly-4-methylpentene, or ethylene-propylene copolymers, ethylene-propylene copolymers, ethylene-vinyl chloride copolymers, propylene-vinyl chloride copolymers or mixtures of these polymers.

The addition amount of the olefin resin is essential to be 25 to 88.75 parts by mass, and more preferably, it contributes to the CO ₂ reduction effect and the combustion calorie reduction effect while having the characteristics of polylactic acid. To 50 to 75 parts by mass. Here, when the addition amount of the olefin resin is less than 25 parts by mass, the characteristics of polylactic acid are strong, the CO ₂ reduction effect is remarkably large, and a film excellent in biodegradability / disintegration effect and transparency is obtained. Can do. However, since the characteristics of polylactic acid are strongly influenced, a hard and brittle film can be obtained, and in the impact resistance test, there is a problem that it is not suitable for film use in a situation where the film is broken 10 times or less. On the other hand, when the addition amount of the olefin resin exceeds 88.75 parts by mass, the heat seal strength value also shows a high value due to the large content of the olefin resin, and even in the impact resistance, an impact of 30 times or more is given. Although a film with excellent mechanical properties can be obtained without causing bottom-out or tearing from the main body, the effect of reducing calories burned cannot be obtained.

In the present invention, examples of the modified polyolefin compound include the following copolymers (1) to (6).
(1) Copolymer obtained by graft reaction of (meth) acrylate ester or styrene to copolymer of α-olefin and acrylate ester
(2) Copolymer obtained by reacting α-olefin and vinyl acetate copolymer with (meth) acrylate or styrene with graph
(3) Copolymer of α-olefin and glycyl group-containing monomer having ethylenically unsaturated bond
(4) Copolymer obtained by graft reaction of α-olefin, ethylene, acrylic ester and acid anhydride
(5) Copolymer in which maleic acid is graft polymerized to α-olefin and ethylene-propylene copolymer
(6) Ethylene copolymer comprising ethylene and α-olefin other than ethylene Copolymer obtained by graft polymerization of unsaturated carboxylic acid or derivative thereof As the α-olefin in the above-mentioned copolymer, ethylene, pyropyrene, butene -1, hexene-1,4-methylbutene-1,4-methylpentene-1, and ethylene and pyropyrene are preferable.

  Examples of the glycyl group-containing monomer having an ethylenically unsaturated bond include diglycidyl acrylate, diglycidyl methacrylate, itaconic acid monoglycidyl ester, butenetricarboxylic acid diglycidyl ester, butenetricarboxylic acid monoglycidyl ester, and butenetricarboxylic acid. Examples thereof include glycidyl esters such as acid triglycidyl ester, vinyl glycidyl ether, allyl glycidyl ester, and glycidyloxyethyl ether. Examples of the (meth) acrylic acid ester include methyl acrylate, methyl methacrylate, ethyl acrylate, and ethyl methacrylate. As the impact modifier, methyl methacrylate is particularly preferable.

As said modified | denatured olefin compound, it is marketed by the brand name of following (1)-(6).
(1) (Ethylene + maleic anhydride) graft copolymer (trade name: Admer, manufactured by Mitsui Chemicals, Inc.)
(2) α-ethylene-propylene copolymer (trade name: Tafmer, manufactured by Mitsui Chemicals, Inc.)
(3) Ethylene-glycidyl methacrylate copolymer grafted PMMA (trade name: Modivar A4200, manufactured by NOF Corporation)
(4) Ethylene-ethyl acrylate copolymer grafted PMMA (trade name: Modivar A5200, manufactured by NOF Corporation)
(5) Ethylene-vinyl acetate copolymer grafted PMMA (trade name: Modivar A6200, manufactured by NOF Corporation)
(6) Ethylene-ethyl acrylate-maleic anhydride copolymerized PMMA (trade name: Modivar A8200, manufactured by NOF Corporation)
The amount of the modified olefinic compound added is necessarily 6.75 to 45 parts by mass, and more preferably 15 to 30 parts by mass from the viewpoint of contributing to unevenness of the resin on the film surface and glossiness. More specifically, it is preferable that the modified polyolefin compound is composed of 1.5 parts by mass or more with respect to the polylactic acid resin.

When the addition amount of the modified polyolefin compound is less than 6.75 parts by mass, the improvement of physical properties and the compatibility effect due to the addition are not recognized. Further, the present invention finds that the CO ₂ reduction rate (%) is 1.5 times or less when the polylactic acid resin corresponding to 1.5 parts or more by mass part ratio of the modified polyolefin compound to the polylactic acid resin component is contained. The reduced CO ₂ reduction rate (%) cannot be satisfied. On the other hand, when the addition amount of the modified olefinic compound exceeds 45 parts by mass, a compatibility effect between the polylactic acid resin and the olefinic resin is recognized. However, as a whole, the content of the polyolefin-based compound increases, and it is not possible to produce a plant-derived effect using a living organism as an energy source or an industrial raw material, and the raw material price of the modified polyolefin-based compound is compared with that of a polyolefin-based resin. When the conversion rate of the modified polyolefin compound is increased by 2.5 times or more, there is a problem that the cost of the molded product is increased.

In the present invention, although not particularly limited, a plasticizer may be added as necessary as long as there is a problem such as openability and raw fabric slippage during molding.
Plasticizers include aliphatic dibasic acid esters, phthalic acid esters, adipic acid esters, hydroxy polycarboxylic acid esters, and glycol from the viewpoint of compatibility with all of polylactic acid and modified polyolefins and plasticizing ability. Acid derivatives, ether ester derivatives, glycerin derivatives, alkyl phosphate esters, dialalkylates, diesters, tricarboxylic esters, polyesters, epoxies, sulfonic acid amides, ether esters, sobensoates, polyglycol diesters, alkyl alkyls It is preferably composed of at least one selected from the group consisting of a latex diester, a fatty acid ester, an alkylate monoester, and a citrate plasticizer.

  In the present invention, as necessary, pigments, antioxidants, plasticizers, antistatic agents, matting agents, deterioration inhibitors, fluorescent brighteners, ultraviolet absorbers, ultraviolet stabilizers, lubricants, crystal nucleating agents, metals Powder, an inorganic filler, carbon black, a thickener, a viscosity stabilizer, etc. can be added in arbitrary ratios.

  In the present invention, in order to carry out the present invention and obtain the polylactic acid / polyolefin-based composition according to the present invention, a typical film forming method such as an inflation method, a T-die method, or a biaxially stretched film molded product. Examples of molding methods include injection molding methods, blow molding methods, and extrusion net molding methods found in drained nets. In the present invention, description will be made based on a general film molding method.

In the present invention, a mixing method and a mixing apparatus for polylactic acid resin, olefin resin, modified polyolefin compound and the like are not particularly limited, but those that can be continuously processed are industrially advantageous and preferable. For example, there are the following methods (1) and (2).
(1) A method in which two or more types of pellets are mixed at a predetermined ratio, and the resin is put into an hopper of an extrusion molding machine such as an inflation method, a T-die method, or a biaxially stretched film as it is, melted, and immediately molded.
(2) Each resin was melt-mixed in a twin-screw extruder molding machine, and then pelletized, and the pellets were put into an hopper of an extruder such as an inflation method, a T-die method, or a biaxially stretched film. A method of melting and molding.

  The mixing method (1) can reduce the thermal deterioration of the resin and can be molded all at once in the process, so there is almost no increase in molding cost. In the mixing method (2), since pelletization is performed by melt extrusion once before forming a film or the like, it is necessary to substantially prevent deterioration and deterioration of the polymer, and further, pellet molding is performed to obtain a molded product. The product and the process must be divided into two steps. Therefore, it leads to a cost increase in molding.

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to these examples.
(Comparative Example 1)
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 10% by weight, olefin-based resin (trade name: Evolue SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen-Medium density polyethylene ( 90% by weight (hereinafter referred to as “Metalsen LLDPE”) was mixed by a dry blend method, and a film having a blow ratio of 2.5 times and a thickness of 25 μm was formed using an inflation molding machine at a molding temperature of 150 to 200. The room temperature was kept constant at 25 ° C.

(Comparative Example 2)
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 2.5% by weight, olefin resin (trade name: Evolu SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen LLDPE 93. 75% by weight, and modified polyolefin (trade name: Admer LB548, manufactured by Mitsui Chemicals, Inc.), for example, 3.75% by weight of EEDCA are mixed by a dry blend method, and a blow ratio is 2.5 times using an inflation molding machine. A film having a thickness of 25 μm was formed, and the molding temperature at this time was kept constant at 150 to 200 ° C. and the room temperature was 25 ° C.

Example 1
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 4.5% by weight, olefin resin (trade name: Evolu SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen LLDPE 88. 75% by weight and modified polyolefin (trade name: Admer LB548, manufactured by Mitsui Chemicals), for example, EEDCA 6.75% by weight are mixed by a dry blend method, and a blow ratio is 2.5 times using an inflation molding machine. A film having a thickness of 25 μm was formed, and the molding temperature at this time was kept constant at 150 to 200 ° C. and the room temperature was 25 ° C.

(Example 2)
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 10% by weight, olefin resin (trade name: Evolu SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen LLDPE 80% by weight, And modified polyolefin (trade name: Admer LB548, manufactured by Mitsui Chemicals, Inc.) For example, EEDCA 10% by weight is mixed by a dry blend method, and a film having a blow ratio of 2.5 times and a thickness of 25 μm is manufactured using an inflation molding machine. The molding temperature at this time was kept constant at 150 to 200 ° C. and the room temperature was kept at 25 ° C.

(Example 3)
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 10% by weight, olefin resin (trade name: Evolue SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen LLDPE 75% by weight, And modified polyolefin (trade name: Admer LB548, manufactured by Mitsui Chemicals Co., Ltd.) For example, EEDCA 15% by weight is mixed by a dry blend method, and a film having a blow ratio of 2.5 times and a thickness of 25 μm is manufactured using an inflation molding machine. The molding temperature at this time was kept constant at 150 to 200 ° C. and the room temperature was kept at 25 ° C.

Example 4
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 30% by weight, olefin resin (trade name: Evolu SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen LLDPE 25% by weight, And modified polyolefin (trade name: Admer LB548, manufactured by Mitsui Chemicals, Inc.), for example, 45% by weight of EEDCA is mixed by a dry blend method, and a film having a blow ratio of 2.5 times and a thickness of 25 μm is manufactured using an inflation molding machine. The molding temperature at this time was kept constant at 150 to 200 ° C. and the room temperature was kept at 25 ° C.

(Comparative Example 3)
Polylactic acid (trade name: Eco plastic U'z B-2, manufactured by Toyota Motor Corporation), for example, PLA 35% by weight, olefin resin (trade name: Evolue SP2520, Nippon Polyethylene Co., Ltd., for example, Metalsen LLDPE, 12.5% by weight % And modified polyolefin (trade name: Admer LB548, manufactured by Mitsui Chemicals, Inc.), for example, EEDCA 52.5% by weight is mixed by a dry blend method, and blow ratio is 2.5 times and thickness is 25 μm using an inflation molding machine. At this time, the molding temperature was 150 to 200 ° C., and the room temperature was kept constant at 25 ° C.

(Comparative Example 4)
An olefin resin (trade name: Novatec UF421, manufactured by Nippon Polyethylene Co., Ltd.), for example, LLDPE 100% by weight was formed into a film having a blow ratio of 2.5 times and a thickness of 25 μm using an inflation molding machine.

(Comparative Example 5)
Olefin-based resin (trade name: Novatec UF421, manufactured by Nippon Polyethylene Co., Ltd.), for example, low-density polyethylene (hereinafter referred to as LDPE) 100% by weight using a blow molding machine with a blow ratio of 2.5 times and a thickness of 25 μm Was formed.

The materials of Examples 1 to 4 and Comparative Examples 1 to 5 were comparatively evaluated by the following evaluation items and evaluation methods, respectively. The results are shown in Tables 1 and 2 below.

(Evaluation items and evaluation methods)
(1) Workability
Processability is based on the example, compatibility, discharge in continuous molding, film forming, frost line stability, winding stability, film opening, wrinkle and transparent molded product state confirmed.
(2) Specific gravity
The specific gravity was measured in accordance with the plastic density and specific gravity measurement method described in JIS-K-7112.

(3) Melting point
The melting point was measured with a differential thermal analyzer (DSC-50 type, manufactured by Shimadzu Corporation) based on the thermal analysis measurement method described in JIS-K-7121.
(4) Tensile breaking strength and breaking elongation
The tensile breaking strength and breaking elongation were measured according to the tensile test method described in JIS-K-1702. The test piece used the shape of No. 4 type test piece described in JIS-K-7127.

(5) Tear strength
The tear strength was measured according to the tear test method described in JIS-K-7128C method (right angle tear method).
(6) Heat seal strength
The heat seal strength was measured according to the heat seal strength measurement method described in JIS-Z-1711. The sealing part of the bag made by bag making was measured with a general bag making machine under the conditions of a temperature of 200 ° C. and a shot number of 50 sheets / min.

(7) Impact resistance
After making into a bag of any size, half the total volume of water was added and vigorously shaken up and down to check the state of bottoming and tearing from the bag body.

(8) Burning calories
From the calorie of the raw materials used in the study, polylactic acid 19 kJ / g, polyethylene 46 kJ / g, and modified polyolefin 46 kJ / g, the theoretical calculation was performed from the following formula.
Burning calories (kJ / g) = 19 × X + 46 × Y + 46 × Z / 100
However, X: parts by mass of polylactic acid resin, Y: parts by mass of olefin resin,
Z: parts by mass of the modified polyolefin compound (9) CO ₂ generation amount during combustion
As the amount of CO ₂ generated during combustion, the amount of CO ₂ generated per 1 kg of the film formed in Examples and Comparative Examples was calculated. The calculation method is “Health Digest. 14 (1). 1 (1999, written by Hitomi Ohara)” and “CO ₂ generation described in“ Amount of CO ₂ Generated during Plastic Oxidation Decomposition (Chemical Structure Origin) ”. It was calculated based on the amount calculation method. The calculation method is as follows.
CO ₂ generation amount (kg-CO ₂ / kg-Resin)
= (Component amount derived from fossil resources) x 3 _{kg / CO2} + (component amount derived from biomass) x 2 _{kg / CO2}
Furthermore, according to “Health Digest. 14 (1) .1 (1999, by Hitomi Ohara)”, “the amount of CO ₂ generated during oxidative degradation of plastics (derived from the chemical structure)”, it can be seen that polyethylene such as LLDPE and LDPE Since the CO ₂ generation amount during combustion is 3.0 kg per kg, the CO 2 generation reduction rate (%) per kg of the molded products obtained in Examples 1 to 5 and Comparative Examples 1 to 4 Was calculated from the following formula.
CO ₂ emission reduction rate (%)
= 100-{(CO ₂ generation of example, comparative example composition _/ 3.0 _{kg / CO 2} ) × 100}
Table 1 shows the composition of the polylactic acid / polyolefin composition in Examples 1 to 4 and Comparative Examples 1 to 5 and the composition ratio, conditions such as the blow ratio, and compatibility, ejection stability, film formation stability, etc. The results of molding conditions and mechanical properties of molded products are shown.

  According to the result of Table 1, it is comprised by three components by the combination of the polylactic acid resin which is the conditions required for implementing this invention, polyolefin resin, and a modified polyolefin compound, and polylactic acid resin is 4.5-30. Part by mass, 25 to 88.75 parts by mass of a polyolefin resin, 6.75 to 45 parts by mass of a modified polyolefin compound, 1.5 times or more of the modified polyolefin compound relative to the polylactic acid resin, and In Example 1, Example 3, and Example 4 manufactured according to the condition that the total amount of the three components is 100 parts by mass, the molding of the biomass type film containing the plant-derived resin component is stable. I understand that.

  On the other hand, Comparative Example 1 and Example 2 in which the modified polyolefin compound is contained 1.5 times or less with respect to the polylactic acid resin are in a relatively good situation in terms of molding such as discharge amount and film forming property. Resin unevenness is found on the surface of the film obtained in 1), which is not preferable in terms of appearance, and further, a delamination phenomenon is observed between the film layers, and it has characteristics as a biomass type film containing the plant-derived resin component of the present invention. Not.

Furthermore, although Comparative Example 3 has a large CO ₂ reduction effect, it can be seen that there is a tendency to partially crease during molding, and as the polylactic acid resin component increases, the proportion of the modified polyolefin compound component also increases. Due to the tendency, the raw material cost is 2.5 times or more higher than the polyolefin resin price.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, the polylactic acid / polyolefin composition of the embodiment is a case of molding by an inflation method, but is not limited thereto. Furthermore, you may combine suitably the component covering different embodiment.

Claims (3)

It is composed of three components by a combination of polylactic acid resin, polyolefin resin and modified polyolefin compound, 4.5-30 parts by mass of polylactic acid resin, 25-88.75 parts by mass of polyolefin resin, 6.75- A polylactic acid / polyolefin composition comprising 45 parts by mass, wherein the total amount of the three components is 100 parts by mass. 2. The polylactic acid / polyolefin composition according to claim 1, wherein the modified polyolefin compound is contained 1.5 times or more with respect to the polylactic acid resin. The polylactic acid / polyolefin composition according to claim 1 or 2, wherein the polylactic acid resin is a resin obtained by lactic acidizing and polymerizing plant starch.