JPH04189870A - Degradable resin composition - Google Patents

Abstract

PURPOSE:To obtain a degradable resin composition having a proper usable life and excellent degradation with light and microorganisms, comprising a thermoplastic resin, a conjugated diene-based (co)polymer and, if necessary, a natural polymer compound and/or a metallic oxide. CONSTITUTION:A first composition comprising (A) a thermoplastic resin (preferably polyethylene) having <=170 deg.C,. preferably <=160 deg.C melt temperature and (B) a component composed of B1:1-90wt.% 1,2-polybutadiene having >=70%, preferably >=85% 1,2-bond and >=5%, preferably 10-40% crystallinity and B2:10-99wt.% conjugated diene-based (co)polymer (e.g. preferably styrene-isoprene copolymer) except B1. A second composition comprising 0-9wt.% component A, 0-9wt.% component B1, 10-100wt.% component B2 and (C) a natural polymer compound and/or a metallic compound.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention comprises a thermoplastic polymer, a conjugated diene (co)polymer, and optionally a natural polymer compound and/or a metal oxide. The present invention relates to a disintegrating resin composition having a suitable pot life and excellent disintegration properties due to light and microorganisms.

[Prior art] Olefin polymers such as polyethylene and polypropylene are used for shopping bags, packaging sheets, garbage bags,
It is widely used in 6-pack rings, blow containers, and other applications where it is difficult to collect after use, such as disposable packaging materials and agricultural films. After use, these materials are either incinerated or disposed of in landfills, and landfilling is the most convenient method for disposing of plastic waste. However, since the garbage used as packaging materials made of these olefin plastics is bulky, more space is required for landfilling, and the bulk density is small, making the foundation of the landfill weak. Furthermore, garbage that is landfilled or discarded in the environment remains in its original form without being disintegrated, so it is important to beautify the environment.
This is a major problem from the standpoint of conservation or wildlife protection.

Photo-degradation and bio-degradation of plastics are attracting attention and demand from the standpoint of volume reduction in landfilling, assimilation of landfilled or discarded garbage into the environment, and protection of wild animals. ing.

Plastics, especially olefinic polymers alone or various resin compositions in which olefinic polymers are blended with substances that impart photodegradability or biodegradability, are commercially available, but these begin to disintegrate during use and are susceptible to Since the usage time is not appropriate, there are problems in that its uses are limited and its disintegration is insufficient.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems.In the stage of use, when left as garbage or disposed of, decomposition occurs rapidly due to light and/or microorganisms, and furthermore, the decomposition is extremely rapid. Aimed at large resin compositions.

[Means for Solving the Problems] The present invention provides (1) (A) a thermoplastic polymer having a melting temperature of 170° C. or lower, and (B) 1 to 90% by weight of 1,2-polybutadiene and 1
．． A collapsible resin composition (hereinafter referred to as
(2) (A) a thermoplastic polymer having a melting temperature of 170° C. or less; (B) 0 to 90% by weight of 1.2-polybutadiene and 1
A disintegrating resin composition ( below,
(referred to as "Composition ■").

The present invention will be explained in detail below.

Component (A) Component (A) is a thermoplastic polymer having a melting temperature of 170°C or less, preferably 160°C or less, more preferably 90 to 150°C, such as polyolefin, olefin copolymer, styrene polymer, etc. Examples include hydrogenated products of polymers, acrylic polymers, vinyl chloride resins, non-grade nylons, polycarbonates, polyamides, polyesters, and block copolymers of styrene and butadiene.

The melting temperature here refers to the melting point of crystalline polymers,
For glassy polymers, it refers to its glass transition temperature.

Specifically, the polyolefins include low density polyethylene (LDPE) and high density polyethylene (HDPE).
, polyethylene such as linear low density polyethylene (LLDPE), polypropylene, butene-1, hexene-1,
Examples of olefinic copolymers include copolymers of ethylene and one or more α-olefins such as octene-1 and propylene, and polyethylene ionomers; examples of olefinic copolymers include copolymers of ethylene and carbon monoxide; Examples of styrene polymers include polystyrene, A
Examples of the acrylic polymer include BS resin, ABS resin, and styrene-acrylonitrile copolymer, and examples of the acrylic polymer include polymethyl methacrylate and styrene-methyl methacrylate copolymer.

Component (A) is polyolefin, especially LDPE.
Polyethylene such as SHDPESLLDPE, polypropylene, and a copolymer of ethylene and carbon monoxide are preferred.

(B) Component 1.2-polybutadiene (hereinafter referred to as rRBJ) is
Usually, 1,2-bonds account for 70% or more, preferably 85% or more. If the 1,2-bond content is less than 70%, sufficient photodegradability cannot be obtained. The degree of crystallinity is 5% or more, preferably 10 to 40%.

If the crystallinity is less than 5%, fluidity during molding will be impaired, which is not preferable.

The above-mentioned RB is a photodegradation imparting agent, and when added to component (A), the effect of deterioration of the performance of component (A) is extremely small.
It is an ideal photodisintegration agent because the performance of component (A) is fully exhibited during the use stage, the pot life is controlled to be appropriately long, and the subsequent disintegration rate is fast.

In addition, as conjugated diene (co)polymers other than RB,
Polybutadiene with less than 70% of 1,2-bonds, styrene-butadiene random copolymer, styrene-butadiene block copolymer, cis 1°4-polyisoprene, trans 1,4-polyisoprene, random polyisoprene, Examples include 3,4-polyisoprene, styrene-isoprene random copolymers, styrene-isoprene block copolymers, and partially hydrogenated products thereof.

Note that the partially hydrogenated product herein refers to a conjugated diene (co)polymer in which 10 to 90% of the carbon-carbon double bonds are hydrogenated.

Among the above, styrene-butadiene block copolymer,
A styrene-isoprene copolymer is preferred because the processability of component (A) used is excellent and the elastic modulus of the resulting resin composition is less reduced.

Conjugated diene (co)polymers other than RB have the effect of further promoting the disintegration action of the matrix resin.

Component (C) Among component (C), natural polymer compounds include starch, sugar, glucose, kanden, and CMC.

Examples include polysaccharides such as pullulan, chitin, and chitosan. These can be subjected to hydrophobization treatment using a silane coupling agent or the like, if necessary.

Among natural polymer compounds, polymer compounds originating from starch are preferred. Sources of starch include corn, rice, potatoes, and green peas.

Examples of the metal compound include compounds containing alkaline earth metals such as magnesium, calcium, and barium, iron, and titanium.

Specifically, magnesium oxide, magnesium carbonate, magnesium hydroxide, magnesium stearate, the above higher fatty acid magnesium salt, calcium oxide, calcium carbonate, calcium hydroxide, calcium stearate, the above higher fatty acid calcium salt, barium oxide, barium carbonate, Barium hydroxide, barium stearate, barium salt of the above higher fatty acids, ferrous(d)oxide, ferrous(d)chloride
Iron, ferrous(d)hydroxide, ferrous(d)stearate,
Examples include the above higher fatty acid iron salts, titanium oxide, calcium titanate, magnesium titanate, barium titanate, and the like.

Among these, magnesium oxide, titanium oxide, and metal salts of higher fatty acids are preferred because they cause less deterioration in dispersibility and physical properties in polymers.

In composition (2), component (A) is usually 40 to 90% by weight, preferably 60 to 98% by weight, particularly preferably 70% by weight.
~98% by weight, especially 75~97% by weight, component (B) is
Usually 60 to 1% by weight, preferably 40 to 2% by weight, particularly preferably 30 to 2% by weight, especially 25 to 3% by weight.

In addition, here, the ratio of RB in component (B) and the conjugated diene type (co)polymer other than RB is such that RB is 1 to 9 of component (B).
The content of the conjugated diene (co)polymer other than RB is 0% by weight, preferably 2 to 80% by weight, and the content of the conjugated diene (co)polymer other than RB is 10 to 99% by weight, preferably 20 to 98% by weight of the component ('B). If the amount of the conjugated diene (co)polymer other than RB in component (B) is less than 10% by weight in component (B), a sufficient disintegration promoting effect cannot be obtained.

In composition (2), component (A) is usually 40 to 99% by weight, preferably 60 to 98% by weight, particularly preferably 70% by weight.
-98% by weight, especially 75-97% by weight, component (13) is usually 60-1% by weight, preferably 40-2% by weight, particularly preferably 30-2% by weight, especially 25-3% by weight It is blended.

In addition, here, the ratio of RB in component (B) and the conjugated diene type (co)polymer other than RB is such that RB is 1 to 9 of component (B).
The amount of the conjugated diene (co)polymer other than RB is 0% by weight, preferably 2 to 80% by weight, and the amount of the conjugated diene (co)polymer other than RB is 10 to 100% by weight, preferably 20 to 98% by weight of component (B). If the amount of the conjugated diene (co)polymer other than RB in component (B) is less than 10% by weight in component (B), a sufficient disintegration promoting effect cannot be obtained.

Among component (C), the natural polymer compound is usually 0.00 parts by weight per 100 parts by weight of the total amount of components (A) and (B).
The amount is 5 to 30 parts by weight, preferably 1 to 25 parts by weight, particularly preferably 2 to 15 parts by weight.

Furthermore, among component (C), the amount of metal oxide is usually 0.00 parts per 100 parts by weight of the total amount of components (A) and (B).
The amount is 1 to 20 parts by weight, preferably 0.2 to 18 parts by weight, particularly preferably 0.3 to 15 parts by weight.

In addition, in compositions ■ and ■, component (A) and (B)
If the components are difficult to mix, a compatibilizer may be added. As this compatibilizer, carboxyl group,
Examples include polymers containing functional groups such as acid anhydride groups, hydroxyl groups, and epoxy groups, flock copolymers, and kraft copolymers.

Compositions (1) and (H) of the present invention further include, if necessary,
Sensitizers, stabilizers, anti-aging agents, pigments, colorants, modifiers,
Fillers, higher fatty acids, etc. can be added. In addition to the usual inorganic materials, fillers may also include organic materials such as bulbs, natural fibers, wood chips, and wood powder. Furthermore, polymers that are degraded by light or microorganisms, such as polyvinyl alcohol and polyethylene glycol, can also be added.

Manufacturing method The composition of the present invention can be manufactured by, for example, mixing all the components directly in a mixer and then forming a molding material with or without melt mixing.

Another method is to prepare a masterbatch of each component and mix this with one of the components to obtain a molding material.

Furthermore, when using components (A) to (C), for example, all of the components used are directly mixed in a mixer, and then the molding material is prepared with or without melt mixing. Another method is to prepare a masterbatch consisting of at least two selected from components (A) to (C) and mix it with other components to obtain a molding material.

Examples of methods for molding the resin composition of the present invention include molding sheets and films using a T-die extruder or inflation extruder, molding containers using a blow molding machine, and molding various molded products using an injection molding machine. .

The composition of the present invention can be used, for example, in shopping bags,
Various packaging materials such as packaging sheets, garbage bags, trays, and 6-pack rings, disposable household items such as fish cakes, cling film, agricultural films, blow bottle containers, pots, plates, and spoons, and medical products. Examples include equipment, toys, sports equipment, etc.

[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples.

Examples 1 to 7 and Comparative Examples 1 to 4 Components (A) to (C) shown in Table 1 were mixed to form a film (thickness: 20 μm) formed by an inflation method.

The Sunshine Weather Meter was tested for a predetermined period of time under conditions of a black panel temperature of 63° C. and continuous irradiation without rain.

The mechanical properties of the films were determined by punching using a No. 1 machine in the MD force direction, at room temperature (23°C), and at a tensile speed of 500 mm.
/min.

In the evaluation of collapsibility, since the stress actually applied to the sample is important, the evaluation was based on the true strength taking into account the strength and elongation obtained in the tensile test.

The true strength is calculated from the formula below.

The following margins [Effects of the Invention] The resin composition of the present invention does not impair the properties of each resin while being used as a film or molded product, but when left as garbage or buried, it rapidly destroyed by light and/or microorganisms.

Therefore, it can be particularly suitably used for disposable products.

Patent applicant: Japan Synthetic Rubber Co., Ltd. Procedural amendment (voluntary) June 25, 1991, Commissioner of Patents, 2nd tier, Title of invention: Disintegrating resin composition 3, Person making the amendment Relationship with the case: Address of the person: Chuo-ku, Tokyo Details of amendments to Column 5 of "Detailed Description of the Invention" of the specification of Tsukiji 2-chome 11-24 (1) The following sentence is inserted at the end of page 15 of the specification.

Test Example 1 The film prepared in Example 1 was continuously irradiated for 10 hours using an ultraviolet lamp of a Dupanel acceleration tester.The true strength after irradiation was 2855 kg/d, compared to the value immediately after molding. The retention rate was 93%.When the sample after irradiation was shielded from light and left in a constant temperature bath at 60°C for 60 days, the sample disintegrated.

Test Example 2 The film prepared in Example 1 was subjected to outdoor layer IK for one week. The true strength after exposure was 2720 kg/d, which was a retention rate of 88% compared to the value immediately after molding. After irradiation, the sample was shielded from light and left in a constant temperature bath at 60°C for 30 days. The true strength was 1254 kg/d and the retention rate was 41.
It had deteriorated by %.

After being left for another 60 days, the sample had disintegrated.

Comparative Test Example 1 The film prepared in Example 1 was left in a constant temperature bath at 60°C for 60 days without irradiation with light, and the true strength was 2924 kg/al and the retention rate was 95%. Under the conditions of thermal reaction without irradiation with light, there was almost no progress in deterioration.

Comparative Test Example 2 The HDPE film prepared in Comparative Example 1 was continuously irradiated for 10 hours using an ultraviolet lamp of a Dupanel accelerated tester. The true strength after irradiation was 3000 kg/c+d, which was a retention rate of 111% compared to the value immediately after molding. After irradiation, the sample was protected from light and placed in a constant temperature bath at 60℃ for 60 minutes.
When left for days, the true strength was 2860 kg/all and the retention rate was 106%, showing almost no deterioration.

According to these test examples, a film prepared by containing a styrene-butadiene-styrene block copolymer and 1,2-polybutadiene was sufficiently irradiated with light at the initial stage (17) and then subjected to a thermal reaction in which light was blocked. It can be seen that it deteriorates and collapses. ” Procedural Amendment dated February 7, 1992 1, Indication of Case Patent Application No. 169318 of 1990 2,
Title of the invention: Disintegrating resin composition 3; Relationship with the case of the person making the amendment Patent applicant address: 2-11-24 Tsukiji, Chuo-ku, Tokyo Telephone: (03) 5565-6598 4. Date of amendment order: 1992 January 28th (Shipping mortar) 5
, Column 6 of “Detailed Description of the Invention” of the specification subject to amendment, Contents of amendment

Claims (2)

[Claims] (1) (A) A thermoplastic polymer having a melting temperature of 170°C or less, and (B) 1 to 90% by weight of 1,2-polybutadiene and 1
, 2-Polybutadiene A disintegrating resin composition characterized by containing a component consisting of 10 to 99% by weight of a conjugated diene-based (co)polymer other than 2-polybutadiene. (2) (A) A thermoplastic polymer having a melting temperature of 170°C or less, (B) 0 to 90% by weight of 1,2-polybutadiene and 1
, 10 to 100% by weight of a conjugated diene (co)polymer other than 2-polybutadiene, and (C) a natural polymer compound and/or a metal compound.