JP2003192816A - Polyethylene terephthalate-based resin composition and foam molding method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyethylene terephthalate-based resin composition having good moldability, capable of giving a foam-molded product which is excellent in surface properties and impact resistance, and capable of being produced by using recycled polyethylene terephthalate-based resin. <P>SOLUTION: This polyethylene terephthalate-based resin composition comprises (A) a polyethylene terephthalate-based resin, (B) a styrene-base elastomer modifier and/or an acrylic modifier, (C) an acrylic polytetrafluoroethylene processing aid, and (D) a foaming agent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyethylene terephthalate resin composition and a foam molding method thereof,
More specifically, the present invention relates to a polyethylene terephthalate resin composition which gives a foamed molded product having good moldability and excellent surface properties and impact resistance, and a foam molding method thereof.

[0002]

2. Description of the Related Art Polyethylene terephthalate resin (hereinafter referred to as "pet resin") is excellent in mechanical properties and chemical properties. Therefore, PET fiber and pet film improved in crystallization and mechanical strength by stretch orientation. It is widely used for PET bottles by stretch blow molding. However, all of these processing methods utilize the crystallinity of PET resin to achieve strength improvement by stretching orientation, and extrusion molding other than processing methods by these stretching, especially low foaming (profile) extrusion molding As for, the fact is that little attention is paid to it.

In Japan, since April 2000, "Law concerning the separate collection of containers and packaging and promotion of recycling"
However, for the recycling of enormous amounts of PET bottles, for example, fibers, films, and new processing techniques other than blow molding by conventional stretch orientation have hardly been proposed at present. is there. For example, Japanese Unexamined Patent Publication No. 2001-129867 proposes a method for producing a foam using a recycled PET resin. However, in order not to damage the incinerator at the time of disposal, the plastic component ratio is 30% or less. The present invention is characterized in that it is suppressed, and the purpose is to manufacture a so-called high foam material such as a cushioning material and a heat insulating material.

[0004]

When a PET resin is extrusion-molded, a drawdown is large due to the characteristics of the PET resin, and it is difficult to maintain the shape in the melt and shape it in the sizing die. In addition, since the PET resin has a low melt viscosity and melt tension, the cell cannot withstand the decomposition gas pressure of the foaming agent and the cells are broken, resulting in an independent foam having a smooth surface and a normal skin layer. There is a problem that there is no. Furthermore, since PET resin has an ester bond in the molecule,
There is also a problem that the ester bond is hydrolyzed at the time of molding, and the mechanical strength, particularly the impact resistance is lowered, which is one of the causes that hinder the reuse of recycled PET resin.

In view of the above circumstances, the present invention solves the above-mentioned problems of the prior art, and provides a resin composition which gives a foamed molded product having good moldability, surface properties and impact resistance, and a foam molding method thereof. Is provided.

[0006]

Means for Solving the Problems As a result of intensive research to solve the above problems, the present inventor has achieved a desired object by blending a specific modifier and a specific processing aid. They have found the present invention and reached the present invention.

That is, the first aspect of the present invention is that the pet resin (A), the styrene elastomer modifier and / or the acrylic modifier (B), the acrylic PTFE processing aid (C) and the foaming agent ( A pet resin composition comprising D).

A second aspect of the present invention further includes the pet resin composition according to the first aspect, further comprising a hydrolysis inhibitor (E) made of carbodiimide.

In the third aspect of the present invention, the component (A) is 60 to 60%.
100 parts by weight, 5 to 40 parts by weight of the component (B), 1 to 10 parts by weight of the components (C) and (D) with respect to 100 parts by weight of the total of the components (A) and (B). And 0.
The pet resin composition according to claim 1, which is 1 to 5 parts by weight.

According to claim 4 of the present invention, the component (E) is
1 to 100 parts by weight of the total of the component (A) and the component (B)
The pet resin composition according to claim 2, which is 3 parts by weight.

A fifth aspect of the present invention is a pet resin (A).
Is a recycled pet resin, and the pet resin composition according to any one of claims 1 to 4 is included.

A sixth aspect of the present invention is characterized in that the pet resin composition according to any one of the first to fourth aspects is kneaded, heated and melted by an extruder and extruded into the atmosphere. A foam molding method for a resin composition is provided.

A seventh aspect of the present invention relates to a method for foam-molding a pet resin composition according to the sixth aspect, wherein the expansion ratio is 2 times or less.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The PET resin used in the present invention preferably contains 80% or more of ethylene terephthalate repeating units. When the repeating unit of ethylene terephthalate is less than 80%, the excellent mechanical properties and chemical properties, which are characteristics of the PET resin, tend not to be sufficiently exhibited. In the present invention, recycled pet resin can also be suitably used, and it is possible to meet the content of recycled pet resin of 70% or more, which is the Eco Mark certification standard.

Examples of the modifier (B) used in the present invention, which comprises the styrene elastomer, include:
"ARP-1100" (trade name) manufactured by Aron Kasei Co., Ltd., and examples of the acrylic modifier include "Metablene SH-16" (trade name) manufactured by Mitsubishi Rayon Co., Ltd. Used alone or in combination.

Acrylic PTFE used in the present invention
Examples of the (polytetrafluoroethylene) processing aid (C) include “Metablene A” manufactured by Mitsubishi Rayon Co., Ltd.
-3000 "(trade name).

Examples of the foaming agent (D) used in the present invention include inorganic foaming agents such as sodium bicarbonate, sodium carbonate, ammonium bicarbonate and ammonium carbonate,
Nitroso compounds such as N, N'-dimethyl-N, N'-dinitroso terephthalamide, N, N'-dinitroso pentamethylene tetramine, azodicarbonamide,
Compounds such as azodicarboxamide, azobisisobutyrotolyl, azodiaminobenzene, barium azodicarboxylate, benzenesulfonyl hydrazide, toluenesulfonyl hydrazide, sulfonyl hydrazide compounds such as P, P'-oxybis, calcium azide, 4,
Examples thereof include azide compounds such as 4′-diphenyldisulfonyl azide and p-toluenesulfonyl azide, and these may be used alone or in combination of two or more as necessary.

The proportions of the components (A), (B), (C) and (D) in the pet resin composition of the present invention are as follows:
Component (A) is 50 to 100 parts by weight, preferably 70 to 9
0 parts by weight, 5 to 40 parts by weight of component (B), preferably 1
0 to 30 parts by weight, the component (C) is 1 to 10 parts by weight, preferably 2 to 5 parts by weight, and the component (D) is based on 100 parts by weight of the total of the components (A) and (B). 0.1 to 5 per 100 parts by weight of the total of the components (A) and (B).
Parts by weight, preferably 0.3 to 3 parts by weight. (A) ~
When each component of (D) is out of the above range, it is difficult to obtain a pet resin composition which is an object of the present invention and which gives a foamed molded product having good moldability and excellent surface properties and impact resistance.

The pet resin composition of the present invention may further contain a hydrolysis inhibitor (E), whereby the pet is hydrolyzed to have a low molecular weight, whereby the melt viscosity is lowered, It is possible to prevent the impact resistance from decreasing. Examples of such a hydrolysis inhibitor include "Carbodilite" (trade name) manufactured by Nisshinbo Co., Ltd. The blending amount of the component (E) is 1 to 3 parts by weight, preferably 1 to 2 parts by weight, based on 100 parts by weight of the total of the components (A) and (B). If the amount of component (E) is less than 1 part by weight, the effect of suppressing hydrolysis will be insufficient, while if it exceeds 3 parts by weight, moldability and mechanical strength will tend to be reduced.

In the pet resin composition of the present invention, in addition to coloring agents such as pigments and dyes, which are usually used as additives, and fillers, ultraviolet absorbers, lubricants, plasticizers, nucleating agents and antistatic agents are further added. The flame retardant, antibacterial agent, reinforcing filler, etc. may be added alone or in combination of two or more kinds.

The pet resin composition of the present invention is kneaded, heated and melted by an extruder to be extruded into the air to obtain a foamed molded product. The expansion ratio is usually 1.1 to 2.5 times, preferably 1.2 to 2.0 times in order to obtain a foamed molded product having a good surface property. When the expansion ratio is less than 1.1 times, not only is the weight of the foamed molded product increased and the weight reduction becomes insufficient, but it is difficult to obtain a foamed molded product rich in wood texture. On the other hand, when the expansion ratio exceeds 2.5 times, the surface becomes rough and foam is broken, and the surface property is lowered and the impact resistance is lowered.

The pet resin composition of the present invention can provide a foamed PET resin product useful for handrails, handles, step slopes, wiring covers, construction materials, building materials and the like.

[0023]

EXAMPLES The present invention will be described in more detail based on the following examples and comparative examples, but the present invention is not limited thereto.

Examples 1 to 13 and Comparative Examples 1 to 3 A PET resin composition containing recycled pet resin and having the composition shown in Table 1 was extruded under the following extrusion conditions, and 35
A round rod-shaped foamed molded product having a size of mm was obtained, and the molded product was evaluated for surface property, impact resistance and moldability according to the following criteria.
The results are shown in Table 1.

[0025] (Extrusion conditions)   Extruder: 65mm single screw extruder   Extrusion temperature (° C): C1 220 to 240, C2 240 to 250                   C3 250-270, C4 250-270                   D 250-260

(Evaluation method of physical properties) Surface property: The resin is effectively foamed, the surface of the molded product is smooth and no rough skin is observed. △ The surface of the molded product is partially roughened and bubbles are observed. × The surface of the molded body is roughened and bubbles are observed.

Impact resistance: o No cracking is observed when dropped from a height of 2 m. Δ Partial cracking is observed when dropped from a height of 2 m. C. When dropped from a height of 2 m, cracks are observed throughout.

Moldability: Good moldability without drawdown. Δ There is some drawdown, and moldability is somewhat poor. × Large drawdown and difficult to mold.

[0029]

[Table 1]

In Table 1, the trade name and manufacturer name of each component are as follows. (B1) Modifier ARP-1100 Aron Chemical (B2) Modifier METABLEN SH-16 Mitsubishi Rayon (C) Processing Aid METABLEN A-3000 Mitsubishi Rayon (D1) Foaming Agent HK-40B (sodium bicarbonate) Boehringer Ingelheim (D2) Foaming agent HB-201 (azo compound) Eiwa Kasei (E) Hydrolysis inhibitor Carbodilite Nisshinbo Coloring agent SB-HP-1299A Resinocolor Nucleating agent PKP-53 Fuji Talc

As is clear from the results shown in Table 1, according to the pet resin composition of the present invention, the melt viscosity is improved, drawdown is prevented, the moldability is good, and the surface property and impact resistance are good. It is possible to obtain an excellent foamed molded article. In particular, a foamed molded product having a foaming ratio of 2.0 times or less has excellent surface properties and impact resistance, is light in weight and rich in wood texture,
It is suitable as various building materials such as interior and exterior materials.

Further, according to the present invention, the melt viscosity is improved by using the specific modifier (B) and the processing aid (C), and further by using them together with the specific hydrolysis inhibitor (E). In addition, since drawdown is prevented, even if recycled PET resin is used, it is possible to obtain a foamed molded product that has good moldability and excellent surface properties and impact resistance, and saves resources and protects the environment. Also contributes.

[0033]

INDUSTRIAL APPLICABILITY As described above, the PET resin composition of the present invention has good moldability and can provide a foamed molded article having excellent surface properties and impact resistance. In particular, a foamed molded product having a foaming ratio of 2.0 times or less has excellent surface properties and impact resistance, is light in weight and rich in wood texture, and is useful as various building materials such as interior and exterior materials. Furthermore, the PET resin composition of the present invention has good moldability even when a recycled PET resin is used, and it is possible to obtain a foamed molded article having excellent surface properties and impact resistance, thus saving resources and protecting the environment. It also contributes to.

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] January 8, 2002 (2002.1.8)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

When a PET resin is extrusion-molded, a drawdown is large due to the characteristics of the PET resin, and it is difficult to maintain the shape in the melt and shape it in the sizing die. In addition, since the PET resin has a low melt viscosity and melt tension, the cells cannot withstand the decomposition gas pressure of the foaming agent and the cells are broken, and a foam with closed cells having a smooth surface and a normal skin layer cannot be obtained. , Is included. Furthermore, since PET resin has an ester bond in the molecule,
There is also a problem that the ester bond is hydrolyzed at the time of molding, and the mechanical strength, particularly the impact resistance is lowered, which is one of the causes that hinder the reuse of recycled PET resin.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29K 105: 04 B29K 105: 04 105: 26 105: 26 C08L 67:02 ZAB C08L 67:02 ZAB F term ( Reference) 4F074 AA32 AA39 AA66 AG20 BA03 BA04 BA13 BA14 BA16 BA18 CA22 CC04Y CC22X CC26Z DA02 DA34 4F207 AA13 AA17 AA24 AA45 AA50 AB02 AC01 AG20 KA01 KA11 KF04

Claims (7)

[Claims] 1. A polyethylene terephthalate resin (A), a styrene elastomer modifier and / or an acrylic modifier (B), an acrylic PTFE processing aid (C) and a foaming agent (D). A characteristic polyethylene terephthalate resin composition. 2. The polyethylene terephthalate resin composition according to claim 1, which further comprises a hydrolysis inhibitor (E). 3. The component (A) is contained in an amount of 60 to 100 parts by weight,
The component (B) is 5 to 40 parts by weight, and the components (C) and (D) are 1 to 10 parts by weight and 0.1, respectively, based on 100 parts by weight of the total of the components (A) and (B). The polyethylene terephthalate resin composition according to claim 1, which is -5 parts by weight. 4. The polyethylene terephthalate resin composition according to claim 2, wherein the component (E) is 1 to 3 parts by weight based on 100 parts by weight of the total of the components (A) and (B). 5. The polyethylene terephthalate resin composition according to any one of claims 1 to 4, wherein the polyethylene terephthalate resin (A) is a recycled polyethylene terephthalate resin. 6. A polyethylene terephthalate resin composition comprising the polyethylene terephthalate resin composition according to any one of claims 1 to 4 which is kneaded, heated, melted and extruded into the air by an extruder. Foam molding method for products. 7. The method for foam-molding a polyethylene terephthalate resin composition according to claim 6, wherein the expansion ratio is 2 or less.