JP2004238607A - Molding and pellet material for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable molding suitable as a disposable food container heatable by microwave oven. <P>SOLUTION: A food serving bowl heatable by a microwave oven is produced by compression molding of a mixture of 30 wt% rice hulls, 45 wt% strong flour, 20 wt% melamine, 2.5 wt% talc and 2.5 wi% polyethylene in a state of powder at 200 Kg/cm<SP>2</SP>filled in a mold kept at 160-170°C. No formaldehyde is detected from the bowl. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a molded article containing a synthetic resin material and a plant fiber material, and a pellet material used for the molding.
[0002]
[Prior art]
Since synthetic resin molded articles cause environmental problems associated with disposal or incineration, biodegradable synthetic resin materials are being developed, but currently available biodegradable synthetic resin materials are very expensive. For this reason, the fact is that it has not gained a place in place of a container made of styrofoam which is consumed in large quantities, for example, as a container for instant noodles or a take-out lunch box.
[0003]
Under such circumstances, Patent Document 1 discloses a method of mixing a carbamide resin, a melamine resin, and a vegetable fiber material, both of which are thermosetting resins, to produce a heat-resistant (specifically, microwave-compatible) molded product. Propose that.
[0004]
Patent Document 2 proposes that a plant fiber material such as rice husk is added to a synthetic resin material to produce a heat-resistant molded product. In this proposal, amino plastics for molds (typically, as a synthetic resin component) are proposed. Has proposed to use a mixture of melamine resin)) and EVA (ethylene vinyl acetate). According to this, it is possible to manufacture a molded article that can withstand heating even in a microwave oven.
[0005]
Patent Literature 3 makes the same proposal as Patent Literature 1. Among them, a thermosetting resin alone such as melamine resin, urea formaldehyde resin, and phenol resin hardens a molded product. It is proposed that a thermoplastic resin be mixed.
[0006]
Patent Literature 3 also proposes to apply a coating to impart heat resistance to a molded product. As the coating material, an application agent containing ceramic powder and water glass (trade name: heatless glass (manufacturer: Ohashi Chemical Industry Co., Ltd.)).
[0007]
Patent Literature 3 discloses, as an application example of the molded article proposed, deep-bottom containers such as bowls and cups, trays for sale display, urine-measuring cups, tableware (for side dish display, sale, microwave-compatible tray, microwave oven) Corresponding bowls, instant noodle cups, bowls, cups for selling soft drinks, and cups for take-out).
[Patent Document 1]
Japanese Patent No. 3072595 [Patent Document 2]
Japanese Patent No. 2968686 [Patent Document 3]
JP-A-2002-205726
[Problems to be solved by the invention]
The present inventor is interested in plant fiber-containing biodegradable plastics proposed in Patent Documents 1 to 3, mixing a thermosetting resin and a plant fiber material in a powder state and molding them according to a normal press molding method. I found out that the moldings taken out of the mold were in pieces and could not be molded well. Similarly, the thermosetting resin, the thermoplastic resin, and the vegetable fiber material were mixed in a powder state and molded according to a normal molding method, but the molded product taken out of the mold was in a disjointed state, I knew the fact that it could not be molded well.
[0009]
An object of the present invention is to provide a molded product that can be heat-molded in a powder state from a plant fiber material such as rice husk and a synthetic resin, and a pellet material used for the molding.
[0010]
A further object of the present invention is to provide a molded article containing a thermoplastic resin for imparting impact resistance to a molded article containing a plant fiber material such as rice hulls and a thermosetting resin, and a pellet material used for molding the molded article. Is to provide.
[0011]
A further object of the present invention is to provide a biodegradable molded product suitable as a disposable food container compatible with a microwave oven and a pellet material used for the molding.
[0012]
A further object of the present invention is to provide a biodegradable molded product suitable as a disposable food container compatible with a microwave oven, which can be provided at a low cost, and a pellet material used for the molding.
[0013]
It is a further object of the present invention to provide a biodegradable molded article which can be provided as a container instead of a styrofoam container and a pellet material used for the molding.
[0014]
[Means for Solving the Problems]
The present inventor, as one aspect, wood chips, plant husks such as rice hulls, cane, sugar cane pomace, plant fiber material such as coffee grounds and synthetic resin and powdered state to mix the plant raw material molded product In the course of the study, it was found that the familiarity between the synthetic resin and the flour was good, and the mixing of the flour made it possible to produce a molded product according to a normal molding method. The present invention is provided based on this finding.
[0015]
According to the present invention, according to the present invention,
It is achieved by providing a molded product obtained by heating and molding a vegetable material comprising a vegetable fiber material and a strong powder and a thermosetting resin, and mixing them with a thermoplastic resin. Good.
[0016]
As the vegetable raw material, in addition to a plant fiber material such as rice husk, a pigment and, if necessary, shellac for preventing formalin may be contained.
[0017]
Further, as proposed in Patent Document 3, a coating such as a coating agent containing ceramic powder and water glass (trade name: heatless glass (manufacturer: Ohashi Chemical Industry Co., Ltd.)) is applied to the molded article of the present invention. May be applied.
[0018]
Molded articles according to the present invention include, for example, trays for sales displays, urine test cups, dishes (for prepared food displays, sales, microwave-compatible trays, microwave-compatible bowls, instant noodle cups, bowls, and cups for soft drink sales. , Take-out cups).
[0019]
【Example】
First specific example Rice husk 45% by weight
Strong powder 10% by weight
Melamine 40% by weight
Talc 2.5% by weight
2.5% by weight polyethylene
[0020]
Second specific example Rice husk 50% by weight
5% by weight of strong flour
Melamine 40% by weight
Talc 2.5% by weight
2.5% by weight polyethylene
[0021]
Third specific example Rice husk 30% by weight
Powerful powder 35% by weight
Melamine 30% by weight
Talc 2.5% by weight
2.5% by weight polyethylene
[0022]
4th example 30% by weight of rice husk
40% by weight strong powder
Melamine 25% by weight
Talc 2.5% by weight
2.5% by weight polyethylene
[0023]
Fifth specific example Rice husk 30% by weight
45% by weight strong powder
Melamine 20% by weight
Talc 2.5% by weight
2.5% by weight polyethylene
[0024]
Sixth specific example Rice husk 50% by weight
Powerful flour 25% by weight
Melamine 20% by weight
Talc 2.5% by weight
2.5% by weight polyethylene
[0025]
Seventh specific example Rice husk 35% by weight
Powerful powder 35% by weight
Melamine 20% by weight
EVA 10% by weight
[0026]
The components presented as the first to seventh specific examples are mixed in a powder state, and then filled in a mold and press-molded to be compatible with a microwave oven having a diameter of 140 mm, a depth of 40 mm, and a wall thickness of 0.5 mm. Made a bowl.
[0027]
The pressing conditions were as follows.
Mold temperature: 160-170 ° C
Molding pressure: about 200 kg / cm ²
Molding time: about 20-60 seconds
The produced microwave-compatible bowl was able to sufficiently withstand heating by a microwave oven, and the strength of the molded product had no practical problem. Also, in a molded article containing 30% by weight or less of melamine resin, formaldehyde could not be detected. From this fact, it can be predicted that even in the molded article according to the present invention containing up to about 50% by weight of the melamine resin, the emission of formaldehyde is within the reference value.
[0029]
Eighth specific example Rice husk 15% by weight
Powerful powder 15% by weight
Melamine MMT 65% by weight
EVA 5% by weight
[0030]
Melamine MMT is a trade name of a synthetic resin material manufactured and sold by Taiwa Corporation (address: 5-6-10 Ueno, Ueno, Taito-ku, Tokyo). Melamine 70% by weight and fine wood chips 30% by weight It is configured. Therefore, in the eighth specific example, the component ratio of melamine is 45.5% by weight.
[0031]
Ninth specific example Rice husk 22% by weight
Powerful powder 15% by weight
Melamine MMT 58% by weight
EVA 5% by weight
[0032]
In the eighth and ninth specific examples, the temperature of the mold was adjusted to 170 to 190 ° C., and molding was performed according to the other molding conditions described above. As a result, a molded product having no practical problem was obtained.
[0033]
Comparative Example 1
Rice husk 30% by weight
Powerful powder 35% by weight
EVA 35% by weight
[0034]
In Comparative Example 1, when a molded product was produced under the above-described press conditions, the molded product itself was broken in the mold.
[0035]
Comparative Example 2
Rice husk 40% by weight
40% by weight strong powder
EVA 20% by weight
[0036]
In Comparative Example 2, when a molded product was produced under the above-described press conditions, a molded product was tentatively formed, but the strength was low and the product could not be used as a bowl.
[0037]
Comparative Example 3
Rice husk 31.5% by weight
Soft flour 30% by weight
Melamine 30% by weight
EVA 5% by weight
Titanium white 2.5% by weight
[0038]
Comparative Example 4
Rice husk 15% by weight
Soft flour 15% by weight
Melamine 65% by weight
EVA 5% by weight
[0039]
Comparative Example 5
Rice husk 17.5% by weight
Soft flour 17.5% by weight
Melamine 60% by weight
EVA 5% by weight
[0040]
In Comparative Examples 3 to 5 described above, the soft powder was mixed in place of the strong powder. However, when a molded article was made under the above-described press conditions, the molded article itself was broken in the mold. Was.
[0041]
Comparative Example 6
Rice husk 36% by weight
Melamine MMT 29% by weight
9% by weight talc
Saponified EVA 24% by weight
[0042]
In Comparative Example 6, the molding temperature was 190 ° C., and the other conditions were the same as the above-mentioned molding conditions. However, the molded product itself was broken in the mold and was broken. It was confirmed that it was not cured when touched. Further, gas was released when the mold was opened.
[0043]
According to the specific examples 1 to 9 described above, a biodegradable plastic molded product produced by press-molding a plant fiber material, a melamine resin, and a strong powder in a powder state contains 50% by weight or less of the melamine resin. And preferably 20 to 40% by weight.
[0044]
The vegetable raw material containing the vegetable fiber material and the strong flour is preferably 65 to 75% by weight, and the melamine resin is preferably 20 to 30% by weight.
[0045]
More preferably, the melamine resin is 25 to 30% by weight and the strong powder is 25 to 45% by weight.

Claims (7)

A molded product comprising a vegetable raw material comprising a vegetable fiber material and a strong powder, and a thermosetting resin, which are heat-molded in a powder state. The molded article according to claim 1, further comprising a thermoplastic resin. The molded article according to claim 1, wherein the thermosetting resin is a melamine resin. The molded article according to claim 1, wherein the thermoplastic resin is EVA or polyethylene. The molded product according to any one of claims 1 to 4, wherein the biodegradable plastic molded product is a food container compatible with a microwave oven. A pellet material for producing a molded product by heating in a powder state,
Vegetable fiber materials,
Flour,
A pellet material comprising: a thermosetting resin. The pellet material according to claim 7, further comprising a thermoplastic resin.