WO2005023918A1

WO2005023918A1 - Thermoplastic resin composition for foamed product and foamed product therefrom

Info

Publication number: WO2005023918A1
Application number: PCT/JP2003/010825
Authority: WO
Inventors: Hiroshi Kawato; Kazuhiro Okuyama; Satoru Kinouchi; Hiroaki Tatematsu
Original assignee: Idemitsu Kosan Co., Ltd.
Priority date: 2003-08-27
Filing date: 2003-08-27
Publication date: 2005-03-17
Also published as: AU2003261746A1

Abstract

A thermoplastic resin composition for a foamed product which comprises (a) 45 to 99.9 wt % of a thermoplastic resin, (b) 0.1 to 50 wt % of a porous filler and (c) 0 to 10 wt % of a melt strength adjusting agent; and a foamed product produced by the foaming of the resin composition. A porous filler added to a thermoplastic resin enhances the easiness in the impregnation of a molten resin with a foaming agent and also acts as a nucleating agent, which allows the formation of a uniform foamed structure with a high expansion ratio.

Description

Description Thermoplastic composition for foaming and foamed body

The present invention relates to a thermoplastic resin composition for foaming containing a thermoplastic resin and a porous filler, and a foam thereof. Height

Plastics are lighter in weight than metals, etc., so their use is expanding in electronic equipment, sundries and automotive parts, but they are lighter and have better physical properties such as strength and impact resistance. There is a further need for materials. One of these technologies is resin foam technology.

Methods for producing a resin foam include a method of mixing a foaming agent (chemical foaming) and a method of foaming by heating (physical foaming).

In recent years, foams have been developed to reduce the weight by forming a void called a cell in the resin by degassing the supercritical fluid after infiltrating the supercritical fluid gas into the thermoplastic resin. ing.

However, with the above-mentioned physical foaming and chemical foaming methods, it has been difficult to easily obtain a uniform foamed structure, particularly by a method using a supercritical foaming method.

In particular, there were drawbacks that it was difficult to dissolve and impregnate the supercritical fluid into the resin during injection molding, and that non-foamed parts were easily formed due to the distribution of injection pressure.

Furthermore, in order to increase the weight reduction rate (expansion ratio), the mold temperature must be raised to the glass transition or near the crystallization temperature, which takes time to cool in the mold and the molding cycle. There has been a problem of a decrease in productivity such as a longer time.

In addition, in the batch method or extrusion molding, even if the expansion ratio is high, only about 1.4 times can be obtained, and if the expansion ratio is further improved, the appearance is extremely poor, and only foams with broken cells can be obtained. There was a disadvantage that there was no.

In view of the above problems, an object of the present invention is to provide a thermoplastic resin composition for foaming having a high foaming ratio and a uniform foamed structure, and a foamed product thereof. Disclosure of the invention

In order to solve this problem, the present inventors have found that, by adding a porous filler to a thermoplastic resin in a foaming composition, the solubility of a foaming agent in a molten resin is improved. It has been found that a highly foamed and uniform foam can be obtained.

According to the present invention, the following thermoplastic resin composition for foaming, foam, and the like are provided.

[1] (a) 45-99.9% by weight of thermoplastic resin,

(b) Porous filler 0.:! ~ 50% by weight, and

(c) melt tension modifier 0-10% by weight,

A thermoplastic resin composition for foaming.

[2] (A) thermoplastic resin 45 ~ 99.9% by weight,

(B) Porous filler 0.1 to 50% by weight,

(C) a melt tension modifier: 0 to 10% by weight, and

(D) foam cells,

Including foam.

[3] The foam according to [2], wherein a maximum cell diameter of the foam cell is 50 or less.

[4] The foam according to the pore volume value of the porous filler is 0. 01 c cZg more or specific surface area is 10 m ² Zg more [2] or [3].

[5] The foaming according to any one of [2] to [4], wherein the porous filler is silica, activated carbon, zeolite, silica gel having an average particle diameter of 50 or less, or fibrous activated carbon having a fiber diameter of 20 zm or less. body.

[6] The foam according to any of [2] to [5], wherein 3§S insect tension II is the following:

(1) thermoplasticity

(2) High ^ f * acrylic resin

(3) Polytetrafluoroethylene with fine g

(4) Composite of polytetrafluoroethylene and acrylic resin

(5) Fiber

(6) High ^ * polyethylene

[7] The self-melting tension IS ^ iJ is (5) fiber reinforced reinforced material or (6) high ^ ¾ polyethylene. The foam according to [6].

[8] The thermoplastic resin may be a polypropylene resin, a polyethylene resin, a polypropylene resin, an acrylonitrile butadiene-styrene copolymer (ABS resin), a polystyrene resin, polyethylene terephthalate, Polybutylene terephthalate, acrylonitrile styrene copolymer (AS resin), syndiotactic polystyrene, polyphenylene oxide, polyacetal, polymethyl methyl resin, polyphenylene sulfide, polyether sulfone, polyarylate, polyamide, polyimide or polyethylene The foam according to any one of [2] to [7], which is phthalate.

[9] The thermoplastic resin according to any one of [2] to [7], wherein the thermoplastic resin is a polymer blend comprising a combination of a polyketone-based resin and a resin selected from any of the following. Foam.

Polyethylene resin, Polypropylene resin, Acrylonite> ~ Butadiene styrene copolymer (ABS resin), Polystyrene resin, Polyethylene terephthalate, Polybutylene terephthalate, Acrylonitrile ^) Styrene copolymer (AS resin), Syndiotactic polystyrene, bolifenylene oxide, polyacetal, polymethacrylmethyl, polyphenylene sulfide, polyether sulfone, polyarylate, polyamide, polyimide or polyethylene naphthylate

[10] The foam according to [8] or [9], wherein the poly-resin-based resin is a resin selected from any of the following.

(1) Intimate recovery

(2) Min! ^ Polymer blend of carbonate and polycarbonate

(3) Poly-Polyone-Polydimethylsiloxane Copolymer

[11] The foam according to any one of [2] to [7], wherein the negative thermoplastic resin is a polymer blend selected from any of the following.

(1) Polyphenylene sulfide and branched polyphenylene sulfide

(2) Syndiotactic polystyrene and anti- »1 raw polystyrene

(3) Syndiotactic polystyrene, anti-impact I raw polystyrene and polyphenylene oxide

[12] Production of a foam in which the foaming thermoplastic resin composition according to [1] is impregnated with a foaming agent, the foaming agent is adsorbed on the porous filter, and the foaming agent is foamed. Method.

[13] The method for producing a foam according to [12], wherein the essence ij is water, a supercritical fluid, or a subcritical fluid.

[14] The method for producing a foam according to [12] or [13] by extrusion molding.

[15] A foam produced by the production method according to any one of [12] to [14]. Brief Description of Drawings

FIG. 1 is a schematic view of an injection molding machine for producing the foam of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail.

First, the thermoplastic resin composition for foaming of the present invention will be described.

The thermoplastic resin composition for foaming of the present invention comprises a thermoplastic resin and a porous filler, or a thermoplastic resin, a porous filler, and a melt tension controller Ij.

The thermoplastic resin is not particularly limited, and is preferably a resin having a high melt tension at a temperature and a shear rate during molding from the viewpoint of foamability.

For example, polyacrylonitrile-butadiene-styrene copolymer (ABS resin), polyacrylonitrile-styrene copolymer (AS resin), syndiotactic polystyrene, polyphenylene resin, polyethylene resin, polypropylene resin, Examples include dilenoxide, polyacetal, polymethyl methacrylate, polyphenylene sulfide, polyether sulfone, polyarylate, polyamide, polyimide or polyethylene naphtholate. Of these, polycarbonate resins, polystyrene resins, polypropylene resins, syndiotactic polystyrene, polyphenylene oxide, and polyphenylene sulfide are preferred, and poly-polycarbonate is particularly preferred from the viewpoint of flame retardancy. It is a system resin. Further, a polymer blend may be used as the thermoplastic resin. Preferably, a polymer blend composed of a combination of a polycarbonate-based concept and a translation selected from any of the following can be used. Polyethylene resin, polypropylene resin, acrylonitrile butadiene styrene copolymer (ABS resin), polystyrene resin, polyethylene terephthalate, polybutylene terephthalate 1 / ", acrylonitrile styrene consolidation (AS resin), syndio Polystyrene, polyphenylene oxide, polyacetal, polymethyl methacrylate, polyphenylene sulfide, polyether sulfone, polyarylate, polyamide, polyimide or polyethylene naphthalate

Among these, from the viewpoint of foamability, polycarbonate-based resins and crystalline thermoplastic resins (polyethylene-based resins, polypropylene-based syllables, syndiotactic polystyrene, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, Preferred is a polymer blend which is a combination of a polyamide and a stereocomplex methyl methacrylate.

Examples of polymer blends other than the polycapone-based resin include polyphenylene sulfide and branched polyphenylene sulfide, syndiotactic polystyrene and rag-resistant raw polystyrene, or syndiotactic polystyrene and «» | Polymer blends such as polyphenylene oxide are preferred.

The above-mentioned polycarbonate resins include linear type, branched type, long chain branched resin, linear polycarbonate polydimethylsiloxane copolymer (hereinafter, PC-PDMS), and long-chain branched PC-PDMS copolymer. Coalescence and the like.

Further, these polycarbonates may be blended and used, for example, a blend of a branched polycarbonate and a linear polycarbonate may be used.

Here, the term “branched polycarbonate” refers to a product obtained by polymerizing a divalent phenol and phosgene or a carbonate compound typically in the presence of a branching agent and, if necessary, a terminal stopper.

The linear polycarboxylic acid is typically obtained by polymerizing a divalent phenol and phosgene or a carbonate compound in the presence of a terminal stopper as required. In other words, except that no branching agent is used, it is the same as the branched poly-one-ponate resin.

Among them, a long-chain branched type polycarbonate is preferred from the viewpoint of foaming properties, and a straight-chain PC-PDMS copolymer is preferred from the viewpoint of flame retardancy. From both viewpoints, the long-chain branched PC-PDMS copolymer is preferred. Particularly preferred. The porous FILLER scratch, pore volume of 0.01 cc / g or more, preferably 0. 2 cc / g or more, and particularly preferably either at 0. 3 c cZg above, or specific surface area is 10 m ² Zg above, preferably 400 meters ² / g or more, more preferably 500 m ² Roh g or more, particularly preferably 1000 m ² Zg above.

If the pore volume is less than 0.01 cc / g or the specific surface area value is less than 10 m ² Zg, the ability to retain the foaming agent is reduced, the foam cells are enlarged, the foam becomes inhomogeneous, and the physical properties of the foam may be reduced. .

Here, the pore volume and the specific surface area are values measured by the BET method (nitrogen adsorption method).

The shape of the porous filler may be plate-like, powdery or fibrous. Preferably, it is in the form of powder or fiber. In the case of a powder, the particle diameter is preferably 1011111 to 50/111, particularly preferably 100 nm to 30 Atm in terms of average particle diameter. If the average particle diameter is less than 1 Onm, secondary aggregation is severe and dispersion becomes difficult. If the average particle diameter exceeds 50 m, mechanical strength may be reduced.

If it is fibrous, its fiber diameter is preferably 2 ηπ! 2020 m, particularly preferably 10 nm〜10 xm. If the fiber diameter is less than 2 nm, it is difficult to disperse due to entanglement, and if the fiber diameter exceeds 20 m, the mechanical strength may decrease.

Preferred examples of the porous filler include porous silica, activated carbon, zeolite, silica gel, and fibrous activated carbon (Adil, Dekin: manufactured by Unitika Ltd.) and the like. The surface of the porous filler may be treated with a reactive compound such as a silane coupling agent, a titanate coupling agent, or an organosiloxane, if necessary. By controlling the interfacial adhesion between the resin matrix and the porous filler, release of the foaming agent from the porous filler during foaming can be expected to be controlled. These may be appropriately selected according to the type of the thermoplastic resin of the resin matrix. The amount of the surface treatment agent to be added is 0.1 to 5% by weight, more preferably 0.2 to 3% by weight, and particularly preferably 0.3 to 1% by weight, based on the thermoplastic resin component. If it exceeds 5% by weight, mechanical strength and heat resistance may be impaired.

When a supercritical fluid is used as the foaming agent, it is more effective to make the foam cells uniform if the porous filler does not absorb water. The amount of water absorption is 5 times for one porous filler %, Preferably at most 2% by weight, particularly preferably at most 1% by weight. In addition to the thermoplastic resin and the porous filler described above, a melt tension adjuster may be added to adjust the melt tension of the thermoplastic resin and control the size of the foam cells of the foam. The following are the melt tension modifiers.

(1) thermoplastic resin having a branched chain structure

Although a thermoplastic resin having a branched chain structure may be used as the thermoplastic resin, a thermoplastic resin having a branched chain structure may be appropriately mixed with a normal linear type thermoplastic resin.

The branching agent may have a skeleton that is the same as or similar to the basic skeleton of the thermoplastic resin molecule and has a reactive group having three or more functional groups. For example, in the case of polystyrene, a branching agent such as trivinylbenzene may be used, and a polymer obtained by polymerizing a styrene monomer containing about 0 to 5% by weight of these may be used. For example, 1,1,1-tris (4-hydroxyphenyl) ethane can be suitably used as a branching agent.

(2) High molecular weight acrylic resin

A similar high melt tension can be exhibited by adding a high molecular weight acryl-based resin in addition to the thermoplastic resin having a branched structure in its molecular structure. The weight average molecular weight of the high molecular weight acryl-based resin is preferably 300,000 or more, more preferably 2,000,000 or more. P53 OA, P 551 A, etc., manufactured by Mirishi Rayon Co., Ltd. can be applied.

(3) Polytetrafluoroethylene

Those having a fibril-forming ability for improving the melt tension are preferred.

(4) Polytetrafluoroethylene-containing composite powder

A3000 manufactured by Mitsubishi Rayon Co., Ltd. or the like can be used.

(5) A young man

For example, you can use glass fiber, carbon fiber, and titanium ^ 7 luminous discs!

(6) High ^? * Polyethylene

High melt polyethylene melt mouth-rate MFR (190 ° C, load 2.16 kg) is preferably about 0.01 to 5 g / 10 minutes, more preferably about 0.03 to 3 g 10 minutes. It is about. It can be appropriately selected according to the desired degree of foaming. Fiber reinforcing material and polyethylene also improve the melt tension, suppress cell enlargement, foam breakage and open cells, and contribute to the formation of fine cells.

The above (1) to (6) may be used alone or in combination.

When the thermoplastic resin composition is composed of the thermoplastic resin and the porous filler, the amount of the thermoplastic resin in the thermoplastic resin composition is preferably from 50 to 99.9% by weight, more preferably from 70 to 99.9% by weight. It is 99.9% by weight, particularly preferably 90 to 99.9% by weight. If the amount of the thermoplastic resin is too small, there is a possibility that the fluidity is insufficient or the mechanical strength is reduced.

The amount of the porous filler to be added depends on the application, required characteristics, the type of the porous filler and the specific surface area, but is preferably 0.1 to 50% by weight, more preferably 0.1 to 30% by weight. It is particularly preferably 0.1 to 10% by weight. If the amount is less than 0.1% by weight, no foaming effect is observed, and if the amount exceeds 50% by weight, the foam cells become large and the mechanical strength of the foam decreases.

Further, when the thermoplastic resin composition is composed of a thermoplastic resin, a porous filler and a melt tension modifier, the amount of the thermoplastic resin in the thermoplastic resin composition is preferably the same as the above, for the same reason as described above. 45 to 99.9% by weight, more preferably 65 to 99.9% by weight, particularly preferably 87 to 99.9% by weight.

Similar to the above, the amount of the porous filler is preferably 0.1 to 50% by weight, more preferably 0.1 to 30% by weight, and particularly preferably 0.1 to 10% by weight. The amount of the melt tension modifiers (1) to (4) may be appropriately selected according to the thermoplastic resin serving as the resin matrix, the application, and the required characteristics, but is preferably 0.1 to 10% by weight, more preferably. Is 0.2 to 5% by weight, particularly preferably 0.5 to 3% by weight. If the added amount is less than 0.1% by weight, the cells may be united and enlarged, depending on the molecular weight of the matrix resin and the presence or absence of a branched structure. If the added amount exceeds 0.1% by weight, the cost increases. In addition, the inherent properties of the matrix resin may be impaired.

The amount of the melt tension modifiers (5) and (6) to be added may be appropriately selected according to the thermoplastic resin serving as the resin matrix, the application, and the required characteristics, but is preferably 0.5 to 50% by weight, more preferably. Is from 3 to 40% by weight. If the amount is less than 0.5% by weight, the melt tension may not be improved. If the amount is more than 50% by weight, the melt tension is too high. In addition to inhibiting bubbles, the residual stress increases, and the warpage and deformation of the molded body are not reduced, that is, the moldability may be deteriorated.

Further, an antioxidant may be added to the thermoplastic resin composition.

When the thermoplastic resin is a polycarbonate-based resin, a phosphite-based or aromatic phosphine-based antioxidant is preferable, and the compounding amount is preferably 0.01 to 0.5% by weight. Selection can be made according to the application and required characteristics.

In addition, inorganic fillers such as alumina, silicon nitride, talc, My power, titanium oxide, carbon black, fused silica, clay compounds (montmorillonite, kaolinite, etc.), glass beads, glass flakes and the like may be added. There is no particular limitation on the particle size and shape, and the amount is preferably 0.1 to 5% by weight, but can be selected according to the application and required characteristics.

Further, reinforcing fibers such as glass fiber and carbon fiber may be added.

If flame retardancy is required, use phosphorous Z polytetrafluoroethylene, metal salt Z polytetrafluoroethylene, organopolysiloxane / polytetrafluoroethylene, non-decabrom, A flame retardant such as magnesium oxide may be added.

Such a thermoplastic resin composition can be melt-kneaded by a single-screw extruder, a twin-screw extruder, or the like, and can be molded, granulated (pelletized), and the like.

Next, the foam of the present invention and the method for producing the same will be described.

The above-mentioned thermoplastic resin composition, or a composition obtained by melt-kneading and granulating the composition in advance can be foamed into a foam.

The maximum cell diameter of the foam cell of the foam of the present invention is preferably 50 / zm or less, more preferably 20 or less. If the maximum cell diameter is larger than 50, the mechanical strength of the foam may decrease.

When foaming the thermoplastic resin composition, foaming agents such as fluids such as water, air, nitrogen, carbon dioxide, and other gases inert to molding materials, supercritical fluids, and subcritical fluids Is used.

When water is used as the foaming agent, an ordinary resin molding machine such as an injection molding machine or an extrusion molding machine can be used as a resin foam production apparatus.

Specifically, a thermoplastic resin composition in an undried state, or a pellet obtained by previously melting and kneading the thermoplastic resin composition is absorbed by a method such as putting into a constant temperature and humidity chamber, It is put into an extruder, melt-kneaded and molded.

The moisture absorption of water is preferably 1 to 10 parts by weight, more preferably 2 to 5 parts by weight, with the total weight of the porous filler being 100 parts by weight. If the 7_K content is less than 1 part by weight, the function as a foaming agent is not exhibited.If the content exceeds 10 parts by weight, coarse foamed cells are formed, and the mechanical properties of the obtained thermoplastic resin composition may be reduced. There is.

In this production method, water is adsorbed on the porous filler, and the porous filler improves the solubility (dissolution / impregnation) of water in the molten resin and also acts as a nucleating agent. As a result, a foam having a satisfactory cell density and cell uniformity can be obtained.

When a supercritical fluid is used as a blowing agent, the supercritical fluid is supplied, and the supercritical fluid is dissolved and impregnated in the thermoplastic resin composition. The apparatus for this is not particularly limited, but for example, an injection molding machine, an extrusion molding machine, an autoclave and the like can be used.

As a method of impregnating a supercritical fluid, for example, as in the case of injection molding or extrusion molding, a supercritical fluid can be supplied and impregnated during melt-kneading of a thermoplastic resin composition.

In addition, a pre-formed thermoplastic resin composition may be impregnated with a supercritical fluid. For example, a molded thermoplastic resin composition is placed in a autoclave and impregnated with a supercritical fluid (batch type).

The supercritical fluid acting as a foaming agent is not particularly limited as long as it can be dissolved in the thermoplastic resin composition and is inert, but from the viewpoint of safety, cost, etc. A mixed gas is preferred.

As a method of infiltrating the supercritical fluid into the thermoplastic resin composition, there are a method of injecting the supercritical fluid in a pressurized or depressurized state, a method of injecting a liquid inert gas by a pump, etc. There is.

The pressure at which the supercritical gas is permeated into the thermoplastic resin composition must be equal to or higher than the critical pressure of the supercritical fluid to be permeated.To further improve the permeation rate, 15 MPa or more, more preferably Is not less than 2 O MPa.

The supercritical fluid is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the thermoplastic resin composition, depending on the type thereof. In particular Preferably, 1 to 5 parts by weight are permeated. If the supercritical fluid is less than 0.1 part by weight, fine foam cells cannot be obtained. If the supercritical fluid is more than 20 parts by weight, the appearance of the foam surface is poor, and coarse foam cells are formed. There is a risk of getting better.

After impregnating the thermoplastic resin composition with the supercritical fluid, the supercritical state is released by lowering the temperature and / or the pressure to foam.

For example, by lowering the pressure in the system at a temperature at which the thermoplastic resin composition is plasticized, the supercritical fluid is expanded to obtain a foam. When an injection molding machine is used, when the thermoplastic resin composition impregnated with a supercritical fluid is filled in a mold, the temperature drops and the supercritical state is released.

Foams produced by the above-mentioned method provide excellent solubility and excellent diffusivity of the supercritical fluid, and the porous filler adsorbs the supercritical fluid so that the supercritical fluid can be added to the thermoplastic resin composition. Since the impregnation amount is improved, fine and uniform foam cells can be formed, and as a result, a resin foam having high mechanical strength and light weight can be obtained. In particular, in a batch system, the time of being placed in a supercritical fluid can be considerably reduced by using the composition of the present invention.

Also, when nitrogen is used as the supercritical fluid, it can be said that this is a method for producing foam that does not affect the global environment and is environmentally friendly.

Since the foam of the present invention has a satisfactory cell density and uniformity of cells, it can be used for OA electronics, automobiles, construction and other fields, high reflection materials, heat insulation materials, sound insulation materials, cushioning materials, low specific gravity materials, and separation. It can be used for membranes, fuel cell separators, low dielectrics, various lightweight structures, optical equipment bases, optical connectors, optical pickups, lamp reflectors, etc.

[Embodiment]

Hereinafter, the method for producing a foam of the present invention will be described with reference to the drawings. In this embodiment, a foam is manufactured by injection molding using a supercritical fluid.

FIG. 1 is a schematic view of an injection molding machine for producing the foam of the present invention.

This injection molding machine 1 is a machine for producing an injection molded product that is a foam of a predetermined shape from the thermoplastic resin composition and a supercritical fluid, and includes an injection molding machine main body 11, a mold 12, Is provided. Further, in order to introduce the supercritical fluid into the injection molding machine, a supercritical fluid introduction device 21 is provided in the cylinder 11 of the injection molding machine main body 11. The supercritical fluid introducing device 21 is a gas cylinder 21 filled with a raw material gas. 1, a pressure booster 2 1 2 that pressurizes the source gas from the gas cylinder 2 1 1 to the critical pressure, and a control pump that controls the amount of supercritical gas pressurized to the critical pressure into the cylinder 1 1 1 2 1 and 3 are provided.

Next, a method for producing a foam using the injection molding machine 1 will be described.

First, the thermoplastic resin composition and various additives as required are charged into the cylinder 111 from the hopper 113.

Open the gas cylinder 2 1 and pressurize and raise the temperature of the nitrogen gas above the critical pressure and above the critical temperature with the booster 2 12. The control pump 213 is opened, and the supercritical fluid is introduced into the cylinder 111 to permeate the part where the thermoplastic resin composition is plasticized (penetration step).

Next, the raw material in the cylinder 11 is moved by the screw 11 and introduced into the gap 12 1 in the mold 12 (introduction step).

At this time, the supercritical fluid may be subjected to mold clamping or counter pressure in order to maintain the supercritical state until the introduction of the raw material into the mold 12 is completed. Critical state maintaining step).

While the skin layer is formed on the surface of the thermoplastic resin composition in contact with the mold 12 and the inside thereof is in a molten state, the movable mold 12 B of the mold 12 is retracted and decompressed to foam. (Pressure drop process).

Further, after cooling and solidification, and a predetermined cooling time has elapsed, the mold 12 is opened and the molded product is taken out.

[Example]

(Production of thermoplastic resin composition for foaming)

Examples 1 to 20

Using a twin-screw kneading extruder (35 mm (see Table 1), a compounded composition comprising various additives such as a thermoplastic resin, a porous filler, and a melt tension modifier shown in Table 1 was used. The mixture was kneaded at a screw rotation speed of 300 rpm under temperature conditions to obtain pellets of the respective examples, and the details of the porous filter are shown in Table 3.

Comparative Examples 1-4

Pellets of each comparative example were obtained in the same manner as in Example 1 at the composition and kneading temperature shown in Table 1. Example 21 to 39

Pellets of each example were obtained in the same manner as in Example 1 at the composition and kneading temperature shown in Table 2. Table 3 shows the details of the porous filler.

table 1

91

Orchid OOZdfAlOd 8l6fi0 / £ 00Z OAV Melt tension modifier 1: High molecular weight acrylic resin

Mitsubishi Rayon Co., Ltd., P 53 OA

Melt tension regulator 2: Polytetrafluoroethylene-containing composite powder

A3000 manufactured by Mitsubishi Rayon Co., Ltd.

Melt tension regulator 3: Polytetrafluoroethylene

Argoflon F5, manufactured by Montefluos

PC: Poly power

Teflon FN1700A, manufactured by Idemitsu Petrochemical Co., Ltd.

Branch PC: Branch Poly-Polyone

Made by Idemitsu Petrochemical Co., Ltd., Even Freon FB 250 OA

PPS: Polyphenylene sulfide

LR2G Branch PPS: Branch Polyphenylene Sulfide

LF3G PPO: Polyphenylene oxide, General Electric Co., Ltd., 646 HI PS: Impact resistant polystyrene, Idemitsu Petrochemical Co., Ltd., I T44 Idemitsu Petrochemical Co., Ltd., Zarek 130 ZC

Branched PP: Branched polypropylene, manufactured by San-Alomer Co., Ltd., PF814

Table 2

To the composition (weight 1%). Lettuce mulberry porridge mulberry porous mulberry porcelain melt bow strength melt tension melt tension

PC- mixing temperature

PC PPS PPO HIPS SPS PP Filer 7. Filer-8 Filer-9 Filer-10 Conditioner 4 Conditioner 5 Conditioner 6

PDMS C)

(% By weight) (% by weight) (% by weight) (% by weight)

⁽ % By weight ^{) (} % by weight ⁾

21 y 丄 O 280

22 / y 丄 Δn \) 200 y 丄 on 280

68 Δ 280

59.5 0.5 40 280

9fi 69 1 30 280

27 b / o oo 280

28 bo Δ 280

29 oy.y 1). 丄 oU 280 Application 30 by.o U.iD 280 Example

31 Do Δo 340

32 69 1 30 340

33 69 1 30 340

34 69 1 30 340

35 14 53 2 30 300

36 16 32 20 2 30 300

37 69.9 0.1 30 200

38 94.5 0.5 5 200

39 69 1 30 200

Melt tension modifier 4:

Asahi Fiberglass Co., Ltd., CS 03 A 409 C Melt tension modifier 5: Carbon fiber

Toho Tenax Co., Ltd., Besphite C6—SRS melt tension modifier 6: high molecular weight polyethylene

Idemitsu Petrochemical Co., Ltd. Idemitsu Polyethylene 640UF MFR = 0.05

PC: polycarbonate

Teflon FN1700A, manufactured by Idemitsu Petrochemical Co., Ltd.

PC-PDMS: Polycarbonate polydimethylsiloxane copolymer

Made by Idemitsu Petrochemical Co., Ltd., Even Freon FC 1700

PPS: Polyphenylene sulfide

Di-i-i-i-pi-P Corporation, L2G

PPO: Polyphenylene oxide, manufactured by General Electric, 646 HI PS: Impact-resistant polystyrene, Idemitsu Petrochemical Co., Ltd., IT44 SPS: Syndiotactic polystyrene

Zarek 130 ZC, manufactured by Idemitsu Petrochemical Co., Ltd.

PP: polypropylene, manufactured by Idemitsu Petrochemical Co., Ltd., E—150GK

Table 3

Specific surface area (BET method) Average particle diameter Fiber diameter Pore volume sa; N o.

(mzo g) (μ.τα) (mm) (g / cc) Porous filler 1 Silica Nippon Kagaku Kogyo Co., Ltd. SI LFAM B 1000 17 ― 1.26 Porous filler 1 2 Activated carbon Mitsubishi Chemical Corporation Diahope 6 D 1100 325 mesh-0.7 Porous filler 3 Activated carbon fiber Adol A 20 2000-13 1.00 Porous filler 4 Silica Mizusawa Chemical Industries P- 603 30 2.2-0.06 Porous Fila-I 5 Silica Mizusawa Chemical Co., Ltd. P-78 A 360 3.3-1.6 Porous filler 6 Silica Mizusawa Chemical Co., Ltd. P-803 180 2.4 0.58 Porous Fila 7 Silica Nippon Aerosil Co., Ltd. 380 380

Porous filler 1 8 Silica Nippon Aerosil 200 CF 200

Porous filler 9 Silica 7K Sawa Chemical Industry Co., Ltd. P—740 T 387 3.8 1.65 Porous filler 10 Calcium phosphate Maruo Calcium Co., Ltd. HAF—30NP 110 2.9

Non-porous filler Silica Denki Kagaku Kogyo KK FB-950 2.8 24

(Production of foam: injection molding method using supercritical fluid as foaming agent)

Example 4 0 to 5 6

The pellets described in Examples 1 to 17 were subjected to microcellular foaming using a microcellular foaming injection molding machine (manufactured by JSW, 180 tons) and a 140 mm square X 2 mm thick plate-shaped mold. A test piece was obtained by molding.

At this time, the injection condition of the nitrogen gas into the cylinder of the injection molding machine was under a pressure of 15 MPa, and the injection amount of the nitrogen gas was 0.3 part by weight.

The foaming ratio at the gate portion and the flow end portion of this test piece was measured.

Table 4 shows the expansion molding conditions and expansion ratios of Examples 40 to 56, Example 57 shown below, and Comparative Examples 5 to 8. The expansion ratio was determined by dividing the density before foaming by the density after foaming.

The cross section of the sample was observed with a scanning electron microscope at a magnification of 500 times, and the foam cell diameter was measured. The observation range was about 0.25 mm X 0.20 mm, and the minimum to maximum cell diameter of the flow end of the test piece of Example 43 in that range was 2 to 13 m.

From the measurement results of the expansion ratio of the obtained sample, it was confirmed that the foam cells were formed uniformly in the sample and that a molded article having a higher expansion ratio than the comparative example could be molded.

Comparative Example 5-8

Test pieces were prepared under the same conditions as in Example 40 except that the pellets prepared in Comparative Examples 1 to 4 were used.

(Manufacture of foam. Injection molding method using water as foaming agent)

Example 5 7

The pellets prepared in Example 2 were absorbed in a constant temperature and humidity chamber at 120 ° C and a humidity of 90% RH for 24 hours, and nitrogen gas was injected by the microcellular foaming injection molding machine. Without molding. At this time, the amount of water absorbed by the pellets was 0.25 parts by weight.

From the measurement result of the expansion ratio of the obtained sample, it was confirmed that the foam cells were formed uniformly in the sample. Table 4

Example 5 8 to 7 3

Test pieces were prepared under the same conditions as in Example 40 except that the pellets prepared in Examples 21 to 36 were used.

Table 5 shows the expansion molding conditions and expansion ratios. Table 5

(Production of foam: extrusion molding method using supercritical fluid as foaming agent)

Examples 74 to 76

Using the pellets prepared in Examples 37 to 39, using an extruded foam sheet manufacturing machine (manufactured by Toshiba Machine Co., Ltd., trade name: DSPU-641), the injection pressure of supercritical CO ₂ was 10 MPa, and the extrusion was performed. At a pressure of 7.5 MPa, a foamed sheet having a width of 300 mm was obtained.

Table 6 shows the expansion molding conditions and expansion ratios. Table 6

(Production of foam: batch method using supercritical fluid as foaming agent)

Examples 7 7 to 8 6

Using the pellets described in Examples 1 to 7 and 18 to 20, press films (thickness: 300 m) were produced at the same temperature as the molding temperature in the above-mentioned injection molding method. The obtained film was cut into a width of 10 mm and a length of 50 mm, put into an autoclave, and carbon dioxide in a supercritical fluid state at an arbitrary impregnation temperature at 15 MPa for 30 minutes. After impregnation, the pressure was rapidly reduced at an arbitrary foaming temperature, and then cooled to room temperature to obtain a foam. The appearance of this foam was observed and its expansion ratio was measured.

Table 7 shows the foaming molding conditions, appearance observations, and expansion ratios of Examples 77 to 86 and Comparative Examples 9 to 12 shown below. In the external appearance observation, “good” means a state where the entire molded product is uniformly whitened, and “defective” means a state where the degree of whitening varies depending on the part. Further, the minimum to maximum cell diameter of Example 80 was measured in the same manner as in Example 43, and as a result, the minimum to maximum cell diameter at the flow end of the test piece was less than 1 im to 7.

Table 7

Comparative Examples 9 to 12

Test pieces were prepared under the same conditions as in Example 77 except that the kneading bellets prepared in Comparative Examples 1 to 4 were used. However, Comparative Example 12 was performed under the conditions of an impregnation temperature of 200 ° C. and a foaming temperature of 165 T :.

From the measurement result of the expansion ratio of the obtained sample, it was confirmed that a molded article having a higher expansion ratio and a good appearance was obtained as compared with the comparative example. Industrial applicability

According to the present invention, it is possible to provide a thermoplastic resin composition for foaming having a high foaming ratio and a uniform foamed structure, and a foam thereof.

Claims

The scope of the claims

1. (a) 45 to 99.9% by weight of thermoplastic resin,

(b) a porous filler 0.1 to 50% by weight, and

(c) melt tension modifier 0-10% by weight,

A thermoplastic resin composition for foaming.

2. (A) thermoplastic resin 45 ~ 99.9% by weight,

(B) Porous filler 0.1 to 50% by weight,

(C) a melt tension modifier: 0 to 10% by weight, and

(D) foam cells,

Including foam.

3. The foam according to claim 2, wherein the maximum cell diameter of the foam cell is 50 or less.

4. The foam according to claim ² , wherein the pore volume of the porous filter is 0.01 ccZg or more or the specific surface area is 10 m2Zg or more. 5. The foam according to claim 2, wherein the porous filler is silica, activated carbon, zeolite, silica gel having an average particle diameter of 50 zm or less, or fibrous activated carbon having a fiber diameter of 20 or less.

6. The foam according to claim 2, wherein β is the tension adjustment (I is any of the following:

(1) Thermoplastic using lit lit

(2) High; acrylic resin

(3) Polytetrafluoroethylene that makes fipri fibers

(4) Composite of polytetrafluoroethylene and acrylic resin

(5) Fiber strength

(6) High ^ ¾ polyethylene

7. mm mM Mmm, (5) n reinforced material or (6) high polyethylene Fiber foam Pia in claim 6.

8. The thermoplastic resin is a polycarbonate resin, a polyethylene resin, a polypropylene resin, an acrylonitritobutadiene-styrene copolymer (ABS resin), a polystyrene resin, a polyethylene terephthalate, a polybutylene terephthalate. Rate, acrylonitrizo styrene copolymer (AS resin), syndiotactic polystyrene, polyphenylene oxide, polyacetal, polymethacrylic J-methyl resin, polyphenylene sulfide, polyether sulphone, polyarylate, polyamide, polyimide or polyethylene 3. The foam according to claim 2, wherein the foam is an annaphthalate.

9. The foam according to claim 2, wherein the unfavorable S thermoplastic resin is a polymer blend comprising a combination of a polyolefin resin and a resin selected from the following. Polyethylene resin, polypropylene resin, acrylonitrino 1-butadiene styrene copolymer (ABS resin), polystyrene resin, polyethylene terephthalate, polybutylene terephthalate, acrylonitrile styrene copolymer (AS resin), syndio Tactic polystyrene, polyphenylene oxide, polyacetal, polymethyl methacrylate, polyphenylene sulfide, polyester sulphone, polyarylate, polyamide, polyimide or polyethylene naphthalate

10. The foam according to claim 8, wherein the polycarbonate resin is fool selected from the following f¾T ^.

(1) Branch polycarbonate warfare

(2) Polymer blend of branched polycarbonate and straight-chain polycarbonate

(3) Polycarbonate polydimethylsiloxane copolymer

11. The foam according to claim 9, wherein the disgusting polycarbonate resin has a shelf selected from the following fTl ^.

(1) minutes !!! ^ Recarnate match (2) Polymer blend of branched polycarbonate and polycarbonate 1

(3) Polycarbonate-polydimethylsiloxane copolymer

1 2. The foam according to claim 2, wherein the hot-dip fat is a polymer blend selected from the following.

(1) Polyphenylene sulfide and branched polyphenylene sulfide

(2) Syndiotactic polystyrene and impact resistant raw polystyrene

(3) Syndiotactic polystyrene, anti-shock [raw polystyrene and polyphenylene oxide

-

1 3. Production of a foam in which the foaming thermoplastic resin composition according to claim 1 is impregnated with a foaming agent, the foaming agent is adsorbed on the porous filler, and the foaming agent is foamed. Method.

14. The method for producing a foam according to claim 13, wherein the source is water, a supercritical fluid, or a subcritical fluid.

15. The method for producing a foam according to claim 13 by extrusion molding.

1 6. A foam produced by the production method according to claim 13.