JP2007099979A - Plastic molded product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flexible and shape retainable plastic molded product able to be used like a metal-made product. <P>SOLUTION: The plastic molded product is produced by extruding and molding a resin composition comprising at least 3 components of a polyester, a polyolefin and a polyfunctional modified vinyl polymer and rolling the extruded product to have ≤80% thickness. The plastic product is also produced by preparing a resin by blending 100 pts.wt. biodegradable polyester resin (flexible plastic group) having 50-1,000% elongation in tensile characteristics with 25-400 pts.wt. biodegradable polyester (brittle plastic group) having 1-30% elongation in tensile characteristics, extruding the resin containing the aforesaid resins as main components and rolling the extruded resin to have ≤80% thickness. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a plastic molded product.

Plastics are used in very large quantities for various applications.
Some of them achieve their purpose by deforming and maintaining their shape. For example, what is bent and used like a fastener needs to keep the bent state first. It doesn't work for things that go back quickly. Moreover, it is necessary to be able to use what is bent and bent repeatedly. For example, in a fastener for fixing a document, the fastener is bent so as not to be pulled out after passing the fastener through a hole in the document. However, if the folded state is not maintained, the document is pulled out.

  Therefore, a metal such as a fastener that can be plastically deformed has been used. However, recently, due to the problem of the global environment, it has been desired to switch from metal to other materials that have been manufactured with conventional metals. This is because, when plastic or paper and metal are fixed, the metal must be removed when disposed of.

  Therefore, a plastic molded article that is made of plastic and is flexible and has shape retention and can be used like metal is provided.

  In view of the present situation as described above, the present inventor has completed the plastic molding of the present invention as a result of intensive studies, and is characterized by at least three components of polyester, polyolefin, and polyfunctional modified vinyl polymer. Biodegradation in which the extrudate is produced by extruding the resin composition, and the extrudate is rolled to a thickness of 80% or less. In another aspect, the elongation in the tensile properties is 50 to 1000%. Mainly composed of 25 to 400 parts by weight of biodegradable polyester resin (fragile resin group) having an elongation of 1 to 30% in tensile properties with respect to 100 parts by weight of polyester resin having flexibility (flexible resin group) The resin used as a component is extrusion-molded, and the extrusion-molded product is produced by rolling to a thickness of 80% or less.

First, the invention of claim 1 will be described.
Polyester in this section means the commonly used polyethylene terephthalate (PET), polybutylene terephthalate (PBT), 1,4-cyclohexyldimethylene terephthalate (PCT), polyethylene naphthalate (PEN), polylactic acid, polybutyl succin And other aliphatic polyesters, aromatic polyesters and derivatives thereof, and in other words, what is necessary is just to have an ester bond in the main chain. Of course, the above-mentioned copolymer may be used.
Moreover, the collect | recovered PET resin and the commercially available thing may be used.
Furthermore, a mixture of the above may be used.

The polyolefin is typically polyethylene or polypropylene, but may be polybutadiene or methylpentene resin. Further, it may be a homopolymer or a copolymer. The copolymer may be random polymerization or block polymerization. In short, the density, the degree of polymerization, etc. are free. In the inventors' experiments, low density polyethylene was preferred. You may use it as a mixture instead of a copolymer.
The mixing amount of the polyolefin is preferably 1 to 30 parts by weight, and more preferably 1 to 8 parts by weight with respect to 100 parts by weight of the polyester. This is to provide an island structure for the polyester sea.

The polyfunctional modified vinyl polymer has a polyolefin portion and a functional group portion, and an elastomer is preferable. The functional group should just react with the carboxylic acid and alcohol of polyester. For example, acid anhydrides, carboxylic acids, alcohols, esters, salts and the like.
Examples of the compound include maleic anhydride-containing styrene plastic elastomer, acid-modified saturated styrene thermoplastic elastomer, styrene-butadiene copolymer hydrogenated organic acid derivative adduct, and the like.
It suffices to have at least one functional group, and not two or more. This is because the purpose is different from that of a so-called crosslinking agent.
A plurality of these may also be used.

  The mixing amount of the polyfunctional modified vinyl polymer is preferably 1 to 30 parts by weight, and more preferably 1 to 8 parts by weight with respect to 100 parts by weight of the polyester. The apparent extensional viscosity can be adjusted by this amount.

  Furthermore, you may mix a filler with 0.1-50 weight part in this invention. Preferably, it is 1-10 weight part. The filler referred to here simply means an extender for powder. There are organic and inorganic types. Examples of the organic type include starch, kenaf, bamboo powder, and examples of the inorganic type include talc, silica, titanium oxide, and charcoal calcium. However, according to the inventors' experiments, talc was the best. Talc is an oxide of magnesium and silicon having crystal water, and can be a crystal nucleating agent. It is thought that crystallization is promoted by adding this.

In the resin used in the present invention, an additive may be further added to the above-described components. For example, pigments, fragrances, ultraviolet absorbers and the like.
In short, as long as it is not contrary to the gist of the present invention, anything such as a bulking agent may be added.

Extrude the above mixture. This method may be a normal method and may not be a special method. The thickness of the extrusion is arbitrary, but it must be taken into account to allow later processing. For example, if it is very thin, rolling described later becomes difficult.
Although it does not specifically limit as thickness, 0.5-5 mm is suitable.

The extruded product is rolled. Rolling here means simply pressing to reduce the thickness, and the method is not limited. For example, passing between the rolling rolls, pressing from above with a pressing tool, and the like.
The thickness is reduced to 80% or less by pressing. Preferably, it is 80 to 40%. If it is 80% or more, there is almost no effect, and it is not necessary to reduce it to 40% or less.

Next, the invention of claim 3 will be described.
A number of biodegradable polyesters as defined in claim 3 are already known, and a typical one is polylactic acid. This is a self-condensation polymer of lactic acid (HOCHCH ₃ COOH) and the structural formula is HO (CHCH ₃ COO) _n H. This is generally not synthesized from petroleum, but mostly produced from plants.
Other linear polyesters (with or without side chains) also have biodegradability. For example, polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, octanediol, decanediol, glycerin, trimethylolpropane, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, fumaric acid , Polycondensation products of polycarboxylic acids such as maleic acid, dodecanoic acid, malic acid, tartaric acid and citric acid and their anhydrides, and ring-opening polymerization products of cyclic esters such as lactide and ε-caprolactone, hydroxybutyric acid And polycondensation products such as hydroxyvaleric acid. These copolymers or a mixture thereof may be used.
Of course, it is not limited to this, and any polyester that has biodegradability may be used.

The biodegradable polyester resin according to claim 3 is a polyester having a tensile property of 50 to 1000% (a flexible resin group may be one type or a plurality of types) and a tensile property of 1 to 30%. 2 kinds of polyester (fragile resin group: one kind or plural kinds) may be included.
In short, the soft resin group stretches considerably until it breaks when pulled. What is necessary is just to select such a thing from said biodegradable polyester. It differs depending not only on the type of polyester but also on the degree of polymerization, polymerization type (block polymerization, random polymerization, etc.), and the like. In the present invention, not the molecular structure but the elongation is important, so the structure is not particularly limited.

  On the other hand, the brittle resin group refers to a polyester having an elongation of 1 to 30% in tensile properties, and may be one type or a plurality of types. In simple terms, when pulled, it breaks with little elongation. Some of these are already commercially available, and polylactic acid is a representative one among the above-mentioned ones.

  The mixing ratio of the two components is preferably 25 to 400 parts by weight for the fragile resin group with respect to 100 parts by weight for the flexible resin group. This was obtained by experiment.

  The resin of claim 3 may be mixed with a filler. As a filler, the same thing as Claim 1 may be sufficient. The mixing amount is 1 to 100 parts by weight with respect to 100 parts by weight of the resin component.

  In the resin of claim 3, an additive may be further added to the above components. For example, pigments, fragrances, ultraviolet absorbers and the like. In short, as long as it is not contrary to the gist of the present invention, anything such as a bulking agent or other resin may be added.

  The resin mixture may be extruded and rolled in the same manner as in the first aspect. The degree of rolling may be the same.

The plastic molding of the present invention has the following advantages.
(1) Compared to conventional plastic products, it has excellent shape retention and flexibility.
(2) It can be obtained simply by rolling after extrusion.
(3) Can be used as a substitute for metal products. Moreover, since it is not a metal, disposal processing is also easy.

  Hereinafter, the present invention will be described in more detail based on preferred examples.

Here, the following was prepared as a mixed component of claim 1.
1 As a resin, Lacia H440 (trademark: polylactic acid manufactured by Mitsui Chemicals)
2 As a polyolefin, ULTZEX 3010F (Trademark: Sumitomo Mitsui Polyolefin Co., Ltd .: Low density polyethylene)
3 Tuftec M1913 (Trademark: Asahi Kasei Co., Ltd .: acid-modified saturated styrene-based thermoplastic elastomer) as a multifunctional modified vinyl polymer
4 As a filler, SL-1500 (trademark: calcium carbonate manufactured by Takehara Chemical Co., Ltd.)
5 Hytron (Trademark: Talc manufactured by Takehara Chemical Co., Ltd.) as filler
The above five components were mixed at various ratios. The mixing ratio is shown in Table 1.

Next, a mixed example of the invention of claim 3 is shown.
1 As a fragile resin group, Lacia H440 (Trademark: Polylactic acid manufactured by Mitsui Chemicals): Elongation in tensile properties: 8%
2 Ecoflex (Trademark: Polybutylene terephthalate / adipate manufactured by BASF): Elongation in tensile properties: 650%
3 As a flexible resin group, GS Pla AZ91T (trademark: polybutylene succinate / adipate manufactured by Mitsubishi Chemical Corporation)
4 As a filler, SL-1500 (trademark: calcium carbonate manufactured by Takehara Chemical Co., Ltd.)
5 Hytron (Trademark: Talc manufactured by Takehara Chemical Co., Ltd.) as filler
The above five components were mixed at various ratios. The mixing ratio is shown in Table 2.

  The materials of the respective component examples in Table 1 and Table 2 were extruded into a rod shape. What was made was a rod-like body having an elliptical cross section (the horizontal axis is the major axis). The ellipse had a long diameter of 2.85 mm and a short diameter (thickness) of 2.5 mm.

Table 3 shows the effects of extruding the materials of component examples 1 to 5 and comparative component examples 1 to 3 shown in Table 1 and rolling them under various conditions. The rolling speed was 1.2 m / min. The thickness after rolling of the roll is 100 times the thickness after rolling divided by the thickness before rolling.
As for flexibility, ◎ is very flexible, ◯ is flexible, Δ is unchanged, and x is harder when rolled.
The shape retention was evaluated as follows. The rod-shaped body obtained by rolling was cut into a length of 130 mm, both ends thereof were pinched loops (both ends were bonded together), and the loops were crushed with a compression jig. The compressive load was 3.7 kg and compressed for 10 seconds. After compression, it was allowed to stand for 24 hours, and the angle opened with a protractor was measured. X is 30 degrees or more, Δ is 20 to 30 degrees, ◯ is 15 to 20 degrees, and ◎ is 15 degrees or less.

As can be seen from Examples 1 to 6 and Comparative Example 1 in Table 3, it can be seen that even with the same component (material), there is a large difference in flexibility and shape retention depending on the degree of rolling.
Moreover, it turned out that it is not effective even if either of polyolefin and a polyfunctional modified vinyl polymer lacks in the mixture of this Claim 1 like the comparative components 1-3.

Similarly to the above, after extrusion-molding the materials of Component Examples 6 to 17 and Comparative Component Examples 4 to 7, the effect of rolling under various conditions is shown in Table 4. Similarly to Table 3, it can be seen that there are differences in flexibility and shape retention depending on the degree of rolling.
Moreover, it turned out that it is not effective only by a weak component or a soft component in the mixture of this Claim 1 like the comparative components 4-6.

Claims (4)

  A plastic molded product produced by extruding a resin composition having at least three components of polyester, polyolefin, and polyfunctional modified vinyl polymer, and rolling the extruded product to a thickness of 80% or less. .   The plastic molded article according to claim 1, wherein 0.1 to 50 parts by weight of a filler is mixed with 100 parts by weight of the resin component.   Biodegradable polyester resin (fragile) with an elongation of 1 to 30% in tensile properties against 100 parts by weight of a biodegradable polyester resin (flexible resin group) with an elongation of 50 to 1000% in tensile properties A plastic molded product produced by extruding a resin whose main component is a resin mixed with 25 to 400 parts by weight of a resin group), and rolling the extruded product to a thickness of 80% or less. The plastic molded product according to claim 3, wherein 1 to 100 parts by weight of a filler is mixed with 100 parts by weight of the resin component.