JP2001072796A - Modifier for recycling plastic and process for recycling plastic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a modifier which, when used in recycling a waste plastic, does not lower the properties of the plastic and to provide a process for recycling a plastic material by using the above modifier. SOLUTION: Provided are a modifier consisting mainly of a low-viscosity polymer having groups that interact on an inorganic substance and groups that interact on an organic substance and a recyclement process comprising melting the plastic to be recycled by heating, and adding the above modifier to the molten plastic to obtain a recycled plastic.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic recycling modifier for recycling discarded plastic, and a plastic material recycling method using the modifier. More specifically, the present invention relates to a plastics recycling modifier that does not reduce the physical properties of plastics when recycling discarded plastics, and a plastic material recycling method using the modifier.

[0002]

2. Description of the Related Art In the recycling of plastics for household electric appliances and vehicles, it has been a problem how to prevent foreign substances from being mixed into collected waste plastic. The foreign substance is a substance other than the polymer compound of the waste plastics, and is a resin or a metal scrap of another kind mixed in a reprocessing / processing step such as sorting and collecting.

[0003] It is difficult to completely remove these foreign substances from the waste collected plastic, and there is a problem in terms of costs such as separation and removal. At the same time, there is a problem that the polymer properties of the recycled plastic are significantly reduced due to the inclusion of foreign matter in the waste collected plastic.
For this reason, a large amount of a plasticizer such as oil is blended during the recycling of plastics to prevent deterioration in physical properties, but it is difficult to recover the original physical properties.

[0004] Under these circumstances, there is a demand for the development of a technique that does not cause deterioration in polymer physical properties even when foreign substances are mixed in during plastic recycling.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a plastic recycling modifier which does not degrade the physical properties of plastic when recycling discarded plastic, and a plastic material recycling method using said modifier. To provide.

[0006]

Means for Solving the Problems The present inventors have made intensive studies and have newly developed a modifier in which a coupling agent is grafted on an olefin polymer having a low viscosity. Due to the low viscosity, the fluidity in the resin matrix is high,
The grafted coupling agent selectively reacts with the contaminant foreign matter that is an inorganic substance. As a result, it has been discovered that the mixed inorganic substance can be selectively included in the resin matrix, so that the deterioration of the polymer properties due to the mixed inorganic substance does not occur. With this technology, material recycling is possible even if there is some contamination of inorganic substances. In addition, since the present modifier has a compatible group having an interaction with an organic substance such as another polymer at the same time, it has an effect as a compatibilizer between the resin matrix and the other polymer. Therefore, the cost of sorting associated with waste collection can be reduced, and a cost merit in the recycling system of waste plastic recycling occurs.

[0007] The present invention relates to a modification for plastic recycling comprising, as a main component, a low-viscosity polymer having an interaction group having an interaction with an inorganic substance and an interaction group having an interaction with an organic substance. Agent.

For example, the plastic recycling modifier of the present invention comprises an interaction group having an interaction with an inorganic substance and an interaction group having an interaction with a polymer other than the low viscosity polymer. As a main component of a low-viscosity polymer having

The low-viscosity polymer has a low viscosity of 1 or more in melt index. In particular, it is preferable to use a low-viscosity polymer having a melt index in the range of 1 to 30, and to introduce an interactive group for an inorganic substance and an interactive group for an organic substance.

The low-viscosity polymer is not particularly restricted but includes, for example, methyl methacrylate-butadiene-styrene resin, acrylonitrile-butadiene rubber,
EVA-PVC-graft copolymer, acrylic resin, butadiene resin, vinyl acetate-ethylene copolymer resin, ethylene-
α-olefin copolymer, propylene-α-olefin copolymer, hydrogenated styrene-isoprene-block copolymer, petroleum resin, polyethylene, polypropylene and the like. In particular, an olefin resin is desirable. Moreover
EVA and EEA are most desirable.

The interacting group for the inorganic substance of the low-viscosity polymer includes, for example, an optionally substituted lower alkoxy group and an acyloxy group. More specifically, lower alkoxy groups such as methoxy group, ethoxy group, propoxy group and β-methoxyethoxy group, and acyloxy groups such as acetoxy group are exemplified. It is also preferable to have alkoxy such as diethoxy, trimethoxy, and triethoxy at the same carbon atom of the low viscosity polymer.

The interacting groups for these inorganic substances are:
The low-viscosity polymer can be introduced by reacting a coupling agent. For example, a silane coupling agent or a titanate coupling agent can be considered. For example, γ-chloropropyltrimethoxysilane, γ-chloropropylmethyldichlorosilane, γ-chloropropylmethyldimethoxysilane, γ-chloropropylmethyldiethoxysilane, vinyltrichlorosilane, vinyltriacetoxysilane, vinyltriethoxysilane, vinyl Trimethoxysilane, vinyl tris (β-methoxyethoxy) silane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-mercaptopropyltrimethoxysilane,
γ-aminopropyltrimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, N-β-
(Aminoethyl) -γ-aminopropylmethyldimethoxysilane, γ- (polyethyleneamino) propyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, methyl Silane coupling agents such as aminoethoxypropyldialkoxysilane, N'-vinylbenzyl-N-trimethoxylipropylethylenediamine salt, isopropyltriisostearoyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (N-amino Ethyl-aminoethyl) titanate, tetraoctylbis (ditridecyl phosphate) titanate, tetra (2,2
Titanium coupling agents such as diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, bis (dioctyl pyrophosphate) ethylene titanate, and other methacrylates / chromium chloride Examples thereof include a chromium-based coupling agent such as a complex and an aluminum coupling agent such as acetoalkoxyaluminum diisopropylate. In particular,
A silane coupling agent having an alkoxy group such as a methoxy group or an ethoxy group is desirable.

[0013] Examples of the interacting group for the organic substance of the low-viscosity polymer include an alkoxy group, an amino group, a mercapto group, a vinyl group, an epoxy group, an acetal group, a maleic acid group, an oxazoline group, and a carboxylic acid group. . Acetal groups and oxazoline groups are more preferred. For example, an oxazoline compound may be reacted.

The modifier for recycling plastics of the present invention comprises reacting a compound having an interacting group with an inorganic substance and a compound having an interacting group with an organic substance with the low-viscosity polymer under appropriate conditions. Let me get it. This introduction reaction can be easily carried out by using a reactive process in an extruder such as a twin-screw kneader without requiring a special reaction vessel.

In the present invention, the plastic to be recycled is an ordinary plastic compound, and is a concept including a high molecular compound such as rubber and plastic. As typical examples, for example, ABS resin, ACS
Resin, alkyd resin, amino resin, ASA resin, bismaleimide triazine resin, chlorinated polyether, chlorinated polyethylene, allyl resin, epoxy resin, ethylene-
α-olefin copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, ethylene-vinyl chloride copolymer, EV
A resin, FRP, ionomer, methacryl-styrene copolymer, nitrile resin, polyester, olefin vinyl alcohol copolymer, petroleum resin, phenol resin,
Polyacetal, polyacrylate, polyallylsulfone, polybenzimidazole, polybutadiene, polybutylene, polybutylene terephthalate, polycarbonate, polyetheretherketone, polyetherketone, polyethernitrile, polyethersulfone,
Polyethylene, polyethylene terephthalate, polyketone, methacrylic resin, polymethylpentene, polypropylene, polyphenylene ether, polyphenylene sulfide, polysulfone, polystyrene, SAN resin, butadiene-styrene resin, polyurethane, polyvinyl acetal, polyvinyl alcohol, polyvinyl chloride, polyvinylidene chloride , Silicone resin, polyvinyl acetate,
Xylene resin, thermoplastic elastomer, EPDM, C
R, BR, nitrile rubber, natural rubber, acrylonitrile butadiene rubber, and butyl rubber.

The plastic recycling modifier of the present invention is particularly suitable for polypropylene, ABS resin,
PS resin and the like.

Plastics to be recycled usually contain substances other than polymer compounds of waste plastics and foreign substances mixed in reprocessing / processing steps such as sorting and collecting. The plastic recycling modifier of the present invention can prevent the deterioration of the physical properties of plastic by selectively including foreign substances mixed in the plastic.

Examples of the contaminants include dusts such as stones, metal fragments, plating scraps, and inorganic substances such as copper wires mixed during molding. These minerals are trapped by interacting with (ie, possibly reacting with) the interacting groups for the inorganics in the modifiers of the present invention. In addition, there are organic contaminants such as dust, hair, fibers, and other debris, and other kinds of polymer pieces such as a printed board mixed during the sorting process. These organic substances are trapped by interacting with the interacting groups for the organic substances (polymers other than the low-viscosity polymer) in the modifier of the present invention. In addition, foreign substances such as electric wire scraps and painted pieces in which an organic substance and an inorganic substance coexist are captured by both organic and inorganic interacting groups in the modifier of the present invention. The contaminant described above is not particularly specified as a substance, but often refers to a substance other than a generally compounded polymer compound.

For example, a discarded plastic compound often contains a filler. The inclusion of these fillers in the waste plastic compound has no effect on the use of the modifiers of the present invention.

As fillers usually blended in plastic compounds, for example, calcium carbonate, magnesium carbonate, magnesium hydroxide, aluminum hydroxide,
Carbon black, aluminum silicate, kaolin, clay, bentonite, talc, silica, wollastonite, zeolite, diatomaceous earth, silica sand, pumice powder, straight powder, alumina, aluminum sulfate, barium sulfate, lithopone, calcium sulfate, magnesium oxide, magnesium oxide Molybdenum sulfide, mica powder, graphite, glass fiber, glass spheres, montmorillonite, iron powder and the like can be mentioned. These inorganic fillers may be used alone or in combination of two or more.

In addition, various additives are often blended in the discarded plastic compound. The incorporation of these additives in the waste plastic compound has no effect on the use of the modifiers of the present invention.

[0022] Additives usually incorporated in plastic compounds include, for example, crosslinking agents, crosslinking accelerators,
Cross-linking accelerators, activators, cross-linking inhibitors, anti-aging agents,
Antioxidants, antiozonants, ultraviolet absorbers, light stabilizers, tackifiers, plasticizers, softeners, reinforcing agents, reinforcing agents, foaming agents, foaming aids, stabilizers, lubricants, release agents, charging Inhibitor,
Denaturing agents, coloring agents, coupling agents, preservatives, fungicides,
Modifiers, adhesives, fragrances, polymerization catalysts, polymerization initiators, polymerization inhibitors, polymerization inhibitors, polymerization regulators, polymerization initiators, crystal nucleating agents, compatibilizers, dispersants, defoamers, etc. No. These may be used alone or in combination of two or more.

It is also possible to mix one or more of the above-mentioned inorganic fillers and additive substances into the modifier of the present invention and use it as a masterbatch.

The present invention also relates to a plastic material recycling method in which a plastic to be recycled is heated and melted, and the plastic recycling modifier is blended to obtain a recycled plastic.

With respect to 100 parts by weight of the plastic to be recycled, the plastic recycle modifier 0.1 to 0.1
It is good to mix 100 parts by weight. Incorporation of the modifier of the present invention into waste plastics is possible by a usual kneading method. For example, kneading may be performed with a kneader such as a roll, a kneader, a Banbury mixer, an intermix, a single screw extruder, or a twin screw extruder.

The modifier of the present invention is also effective in improving the impact resistance of a compound containing the above-mentioned inorganic filler.
The present invention is characterized by the basic technology of selectively including foreign substances in polymers, which is the biggest problem in plastic material recycling. Therefore, the present invention is effective for material recycling of all plastic products. For example, automotive parts such as bumpers, front panels, mats, vehicle parts, household electrical parts,
Construction parts, marine parts, aviation parts, wire and cable materials,
It can be used for material recycling of furniture materials, semiconductor encapsulation materials, printed base materials, musical instruments, cosmetic containers, clock parts, toys, sporting goods, daily necessities such as shoes, and plastic materials such as water pipes, gas pipes and films. Also,
It can be used as an ordinary plastic modifier.

The main features of the present invention are shown below. 1) A plastic recycling modifier of the present invention comprises a compound having an interaction group having an interaction with an inorganic substance (for example, a reactive group having a coupling effect on an inorganic substance) in a low-viscosity polymer; It is obtained by grafting a compound having an interaction group having an interaction (for example, compatibility) to (for example, a polymer other than the low-viscosity polymer). 2) The modifier for recycling plastics of the present invention can prevent the deterioration of the physical properties of plastics by selectively including inorganic foreign substances mixed in the plastics. 3) The plastic recycling modifier of the present invention has a large cost merit because the cost of separation and removal associated with waste collection can be reduced in a waste plastic recycling circulation system. 4) The modifier for recycling plastics of the present invention does not require a special reaction vessel, and can be easily prepared by using a reactive process in an extruder such as a twin-screw kneader.

[0028]

The present invention will be described more specifically with reference to the following examples. [Example 1] (Production of recycled modifier) A recycled modifier was produced by a reactive process using a twin-screw extruder. With the composition shown in Table 1, low viscosity polymer A-710 (EEA resin)
A silane coupling agent A-174 having an inorganic interacting group, and an oxazoline compound having a compatible group with another polymer other than the low viscosity polymer LOXAMID VEP 851
R 1 is extruded using a conventional twin-screw extruder under the conditions shown below, whereby both the silane coupling agent having an inorganic interaction and the oxazoline compound having a compatibility with another polymer are EEA. Grafted on resin. <Extrusion conditions> Temperature setting: feed 160 ° C, kneading unit 180-20
0 ° C., head 160 ° C. Rotation speed: 120 rpm The extruded product under the above conditions was pelletized with a pelletizer to obtain a recycled modifier.

[0029]

[Table 1]

(Evaluation of Recycle Modifier) In order to confirm the performance as a recycle modifier, a PP resin (BC0
3: Copper powder (60 mesh) and calcium carbonate (120 mesh) were mixed as foreign substances into PS resin (NS28: Idemitsu Oil) and ABS resin (HF-5: Mitsubishi Rayon), respectively. The compound was mixed with a recycling modifier, and the polymer properties of the recycled plastic were measured.

[0031]

[Table 2]

Table 2 shows the blending (weight) and test properties of the recycle modifier. In Comparative Examples 1 to 6 and Examples 1 to 3, extrusion was performed using a twin-screw extruder under the following conditions. The extruded plastic compound was molded into a test piece according to the following test method using an injection molding machine, and tested according to the respective test standards. <Extrusion conditions> Temperature setting: feed 180 ° C, kneading unit 180-20
0 ° C., head 180 ° C. Rotation speed: 120 rpm <Test method> Tensile strength: JIS K 7113 Elongation: JIS K 7113 Tensile elasticity: JIS K 7113 Izod impact strength: JIS K 6758

Table 2 shows the experimental results. 1. Regarding PP resin: In Comparative Example 2 in which 5 parts by weight of copper powder (60 mesh) and 5 parts by weight of calcium carbonate (120 mesh) were mixed as foreign substances with respect to Comparative Example 1 in which PP resin was 100%, elongation and Izod impact value were low. Markedly reduced. On the other hand, in Example 1 in which 3 parts by weight of the recycle modifier of the present invention was further added to the compound of Comparative Example 2, the physical properties were recovered as compared with Comparative Example 1 in which no compound was added. .

2. About PS resin: PS resin 100%
In comparison with Comparative Example 3, copper powder (60 mesh) 5
In Comparative Example 4, in which a mixture of 5 parts by weight and 5 parts by weight of calcium carbonate (120 mesh) was used, the Izod impact value was significantly reduced. On the other hand, in Example 2 where 3 parts by weight of the recycle modifier of the present invention was further added to the compound of Comparative Example 4,
Compared with Comparative Example 3 in which nothing was added, the tensile elastic modulus was reduced, but the other physical properties were recovered almost equally. In particular, it showed a remarkable effect on elongation.

3. About ABS resin: ABS resin 10
5% by weight of copper powder (60 mesh) and calcium carbonate (120 mesh) 5
In Comparative Example 6 in which parts by weight were mixed, the elongation and the Izod impact value were significantly reduced. On the other hand, in Example 3 in which 3 parts by weight of the recycle modifier of the present invention was further added to the compound of Comparative Example 6, compared to Comparative Example 5 in which no compound was added,
Physical properties recovered almost equally.

From the above results, it was found that the inclusion of the present modifier allows foreign substances to be selectively included in the resin matrix, so that physical properties caused by the foreign substances do not occur. With this technology, material recycling is possible even if some foreign matter is mixed.

[0037]

According to the present invention, a plastic recycling modifier for recycling discarded plastic and a plastic material recycling method using the modifier are provided.

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Claims (11)

[Claims] 1. A plastic recycling modifier comprising, as a main component, a low-viscosity polymer having an interaction group having an interaction with an inorganic substance and an interaction group having an interaction with an organic substance. 2. A low-viscosity polymer as a main component having an interaction group having an interaction with an inorganic substance and an interaction group having an interaction with another polymer other than the low-viscosity polymer. Item 4. The plastic recycling modifier according to Item 1. 3. The plastic recycling modifier according to claim 1, wherein the low-viscosity polymer has a low viscosity of 1 or more in melt index. 4. The low-viscosity polymer is methyl methacrylate-butadiene-styrene resin, acrylonitrile-butadiene rubber, EVA-PVC-graft copolymer, acrylic resin, butadiene resin, vinyl acetate-ethylene copolymer resin, ethylene- α-olefin copolymer, propylene-α-olefin copolymer, hydrogenated styrene-isoprene-block copolymer, petroleum resin, at least one selected from the group consisting of polyethylene and polypropylene,
The plastic recycling modifier according to any one of claims 1 to 3. 5. The plastic recycling modifier according to claim 1, wherein the interaction group for the inorganic substance of the low-viscosity polymer is a lower alkoxy group and / or an acyloxy group. . 6. The low-viscosity polymer has an interactive group for an organic substance selected from the group consisting of an alkoxy group, an amino group, a mercapto group, a vinyl group, an epoxy group, an acetal group, a maleic acid group, an oxazoline group and a carboxylic acid group. The plastic recycling modifier according to any one of claims 1 to 5, which is selected from at least one kind. 7. The method according to claim 1, wherein the low-viscosity polymer is obtained by reacting a compound having an interaction group with the inorganic substance and a compound having an interaction group with the organic substance by a reactive process. The modifier for plastic recycling according to any one of Items 1 to 6, above. 8. The plastic to be recycled is AB
S resin, ACS resin, alkyd resin, amino resin, AS
A resin, bismaleimide triazine resin, chlorinated polyether, chlorinated polyethylene, allyl resin, epoxy resin, ethylene-α-olefin copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, ethylene-vinyl chloride copolymer , EVA resin, FRP, ionomer, methacryl-styrene copolymer, nitrile resin, polyester, olefin vinyl alcohol copolymer, petroleum resin,
Phenolic resin, polyacetal, polyacrylate,
Polyallylsulfone, polybenzimidazole, polybutadiene, polybutylene, polybutylene terephthalate, polycarbonate, polyetheretherketone,
Polyether ketone, polyether nitrile, polyether sulfone, polyethylene, polyethylene terephthalate, polyketone, methacrylic resin, polymethylpentene, polypropylene, polyphenylene ether, polyphenylene sulfide, polysulfone, polystyrene, SAN resin, butadiene-styrene resin, polyurethane, polyvinyl Acetal, polyvinyl alcohol,
8. Polyvinyl chloride, polyvinylidene chloride, silicone resin, polyvinyl acetate, xylene resin, thermoplastic elastomer, EPDM, CR, BR, nitrile rubber, natural rubber, acrylonitrile butadiene rubber or butyl rubber. The modifier for recycling plastic according to any one of claims 1 to 7. 9. The plastics to be recycled include substances other than polymer compounds of waste plastics and foreign substances mixed in reprocessing / processing steps such as sorting and collecting. The plastic recycling modifier according to any one of the above. 10. A plastic material recycling method in which a plastic to be recycled is heated and melted, and the plastic recycling modifier according to claim 1 is blended to obtain a recycled plastic. . 11. Plastic 100 to be recycled
With respect to parts by weight, the modifier for plastic recycling is 0.1%.
The plastic material recycling method according to claim 10, wherein 1 to 100 parts by weight is blended.