JP3206909B2 - Compressed particle-containing molded article, container made from the molded article, and method for producing the molded article - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a container useful for shipping or storing hazardous fluid materials.

To ship a dangerous fluid material, protect the container holding the fluid material from shocks that may cause damage, and if the container is damaged, contain or contain the fluid material. Good shock protection, which requires the use of shipping containers or packages to prevent spread
Materials that provide impact protection typically have poor fluid containment or fluid absorption properties, and materials that provide good fluid containment or fluid absorption properties have poor impact resistance. Containment of a substance is generally incompatible. An improved shipping container for hazardous fluid materials that provides both impact resistance and fluid containment properties is a combination of stiffer containers that are filled with absorbent material to provide impact resistance. This combination results in a shipping package that is very large relative to the volume of hazardous material loaded in the package.

U.S. Pat. No. 4,560,069 (Simon) discloses that a bottle containing a hazardous substance is placed in a metal can, the bottle being made up of individual top, bottom and sides by a non-elastic and fragile synthetic foam component. A packaging container assembly for transporting hazardous materials containing such bottles, which is surrounded on all sides, is disclosed. The foam component softens the impact on the bottle and provides absorbency in the event of a spill. The individual foam components are kept out of contact with each other by the fiberboard spacers. The spacer separates the top and bottom edges of the bottle from the resin foam and is positioned to protect the fragile foam from collapse by friction from the bottle. The metal can can be suspended into the outer corrugated fiberboard box by the outer fiberboard insert component. The fiberboard insertion component supports the can from contact with the outer fiberboard box and provides a protective buffer zone between the outer fiberboard box wall and the can for can protection.

U.S. Pat. No. 3,999,653 (Haigh et al.) Generally includes a container that is impervious to the hazardous liquids contained therein, the container being subject to the discharge of its contents when subjected to an impact. A packaging container containing a dangerous liquid is disclosed. The container is placed in a first shroud of a liquid permeable material of sufficient strength to contain debris of the container upon breaking. A second shroud is provided over the first shroud, the second shroud having at least one inner wall and an outer wall, wherein the inner wall is liquid permeable, and the objects capable of swelling with the hazardous liquid are the inner and outer walls. And is coextensive with a third covering generally comprising inner and outer walls and a hazardous liquid vapor impermeable membrane.

U.S. Pat. No. 4,213,528 (Kreutz et al.) Discloses that any acid released from a container is formed of an acid-resistant wrap and a separate removable absorbent shield to enclose the acid container. A packaging container for an acid container such as an ampoule or bottle containing an acid, having a sorbent shield containing a substance to neutralize the acid, which is absorbed and neutralized by the shield. Has been disclosed. Absorbent shields are generally porous and still allow the sorbent to have essentially immediate absorption of high, medium and low viscosity acidic liquids.

U.S. Pat. No. Re. 24,767 (Simon et al.) Discloses a packaging container that provides uniform heat, shock, vibration, inertia and fluid impermeable insulation for fragile or delicate objects or materials. The object or substance is a pliable, flexible and resilient porous or foam as well as thermal insulation blanket of the selected thickness which is effective as a protection against shock, vibration, inertial effects, etc. Encased entirely within a sheath, which covers and supports the object or substance, yet has no fluid leakage or impervious shell protects the object or substance against degradation by temperature changes or moisture I do.

U.S. Pat. No. 2,929,425 (Slaughter) discloses a protective pouch comprising an elongated shock absorbing piece having a series of pockets into which the parts to be packaged can be inserted.
The pouch is made such that one or more vertical edges of an impact-reducing strip can be folded over a pocket to cover it, and then the pouch is made of metal cans, wooden boxes or cartons. It is configured to be rolled up or folded for insertion into a shipping container.

U.S. Pat. No. 2,941,708 (Crane et al.) Discloses a helicopter in which six fully joined cut parts are placed such that the edges of the free cut parts make confining contact. Discloses an insulated container made of molded pulp having: The container is shaped to minimize the amount of pulp in direct contact with the articles held in the container so as to minimize heat transfer through the pulp. The container has sufficient rigidity to support the article in the container and not to seize a blanket of insulating air around the article.

U.S. Pat. No. 3,309,893 (Hefflen et al.) Has an elongated torso,
With a square cross section, made of rigid, non-flexible polyurethane foam, with a thermal conductivity in the range of 0.11 to 0.20,
And a cavity having a circular cross-section at one end of the body and a cavity closed at the other end and a lid for a cylindrical cavity having a diameter greater than the diameter of the cavity, the lid being resilient. Made of a flexible, porous polyurethane foam, a sealing cheek in the open end of the cavity to form a tight bond with the cavity wall while allowing gas to escape from within the container Disclosed are such insulated shipping containers that are made to mate and that the foam has a thermal conductivity in the range of 0.22 to 0.35.

U.S. Pat. No. 3,698,587 (Baker et al.) Discloses a self-sealing wall for a container and a substantially rigid support layer of a liquid impermeable material.
A conduit is disclosed that includes a layer of foam and at least one layer of homogeneous elastic polyurethane adhered to the foam.

U.S. Pat. No. 3,895,159 (Yoshimura) is a rigid polyurethane foam molded to conform to the shape of an article to be insulated, having a core layer containing cells and an inner and outer layer containing almost no foam. Discloses a low-temperature insulating material. Glass fibers are embedded at least in the inner surface layer.

U.S. Pat. No. 4,124,116 (McCabe, Jr.) discloses a liquid-absorbing segmented wrapper consisting of an upper and lower filter sheet joined together at outermost contacting edges to form an enclosure. The enclosure is divided into a plurality of sectioned compartments separated from each other by a separating barrier sheet. The separation barrier sheet consists essentially of the water-soluble compound carboxymethylcellulose. Each of the compartmentalized compartments contains a predetermined amount of absorbent granules. The barrier sheet functions to separate when the granules absorb a predetermined amount of moisture to provide increased space to contain the wet granules.

U.S. Pat. No. 4,240,547 (Taylor) discloses a small, reusable specimen mailing container for a fragile specimen container to be shipped safely via the postal service. Two substantially identical L-shaped entanglements (matabl
e) the parts are equipped with long legs with a flat free end and a flat inner surface with each other and short legs with a flat inner surface such that the two parts are in contact with each other Are joined together at the free ends of the long legs. Generally, the long leg of each component is formed with a hole to receive a test tube protruding from the free end of the long leg of the other component. Also, in general, the long legs form a hole that opens from its free end and the inner surface to accept the sliding container,
It is associated with another cavity formed on the inside surface of the short leg. A sheet of sorbent is placed in a recess on the inside surface of the long leg to absorb the leaking fluid. The two parts are combined and placed in a special envelope for mailing.

U.S. Pat. No. 4,481,779 (Barthel) discloses storage for low-temperature, shippable materials, including a container containing a microfibrous structure for holding a liquid gas, such as liquid nitrogen, in the atmosphere and in adsorption and capillary suspension. Discloses a container. The microfibrous structure comprises an adsorbent matrix consisting of a liquid and gaseous nitrogen permeable core and a web of inorganic fibers surrounding the core in a multilayer arrangement.

U.S. Pat. No. 4,495,775 (Young et al.) For cryogenic, transportable materials, including containers containing microfibrous structures to hold a liquefied gas, such as liquid nitrogen, in the atmosphere and in adsorption and capillary suspension. Discloses a container. The microfibrous structure comprises an adsorbent matrix consisting of a liquid and gaseous nitrogen permeable core and a randomly oriented inorganic fiber surrounding the core as a homogeneous body that stably confines.

U.S. Pat. No. 4,584,822 (Fielding et al.) Discloses a shock-mitigating packaging material for use in protecting objects from shock and vibration loads. The shock-absorbing packaging material forms a predetermined arrangement of chambers therein, and a foam material, preferably a low-density material, disposed therein to provide a molded density of no more than 1.5 pounds or 1.5 pounds per cubic foot. Includes a dimensionally stable thermoformed shell having a polyurethane foam.

The present invention provides, in one aspect, an article comprising compressed particles comprising polyolefin microfibers, wherein the article has at least 20% solidity.

In another aspect, the invention includes a shaped article of compressed particles of polyolefin microfibers, wherein the article comprises at least about 2 parts.
Provide a container with 0% solidity. The container is sorbent, impact and heat insulating.
Preferably, the container is surrounded by an impermeable protective outer layer. Particulate materials and other fibrous materials can also be incorporated into the compacted particles of the polyolefin microfibrous structure. The container has excellent structural stiffness, impact resistance and compression resistance, and provides both excellent impact cushioning properties and excellent absorbency.

Containers are particularly useful for storing and transporting hazardous liquid materials, such as acidic materials, loadable materials, and biological fluids, particularly when the materials are packaged in fragile containers. In general, the preferred materials for encapsulation of hazardous liquids are rigid, fragile materials in the form of jars, bottles, vials, or test tubes such as glass or high density thermoplastics such as polyolefins, polycarbonates or polyesters. In handling and shipping, said containers are susceptible to destruction by impact. Container destruction creates the potential for contamination of the surrounding environment and potential human dangers associated with contacting the contaminated and destroyed container and its contents. The excellent shock-absorbing properties and absorbency of the container of the present invention provide an excellent means for safe storage and shipping of hazardous liquid materials in fragile containers.

The containers of the present invention are also useful for storing and shipping materials under cold conditions.

The container of the present invention can also provide excellent insulation for containers stored and shipped within the container.

The invention further comprises, in a further aspect, feeding polyolefin microfiber particles to a mold, applying pressure to the particles, releasing the pressure, and removing the particles from the mold. A method for producing compressed particles of the polyolefin microfiber article of the present invention is provided. The pressure is at least about when the pressure is released.
Sufficient to achieve 20% solidity.

The invention provides, in another aspect, feeding particles of polyolefin microfibers into a mold, applying pressure to mold the particles into the container, releasing the pressure, and compressing the container. Removing from the mold, wherein the pressure is sufficient to achieve at least about 20% solidity when the pressure is released.

Polyolefin fibers useful in the present invention are polyethylene,
It can be made from polypropylene, polybutylene, mixtures thereof, and copolymers of ethylene, propylene and / or butylene. The fibers preferably have a diameter of about 50 microns or less, more preferably about 25 microns or less, and most preferably about 10 microns or less. The fibers are preferably prepared by meltblown, flash spinning or fibrillation. Particularly preferred are microfibers blown in the form of a web which are ground or chopped to form particles of polyolefin microfibers. The particles preferably have an average diameter of about 2 cm or less, more preferably about 1 cm or less, most preferably about 0.5 cm or less, and in small quantities, generally about 5% or less by weight range up to about 10 cm. be able to.

Microfiber webs are described, for example, by Wente, Van A., “Ultrafine thermoplastic fibers”, Industrial Engineering Chemistr.
y, 48, 1342-1346, and Wente, Van A et al., "Preparation of Ultrafine Organic Fibers", Naval Research Laboratories, Repor.
t. No. 4364, issued May 25, 1954, or, for example, US Pat. No. 3,971,373 (Braun), US Pat. No. 4,100,324 (Anderson et al.) And US Pat.
No. 9,001 (Kolpin et al.) Can be prepared from microfibrous webs containing particulate matter.

The web of microfibers is then formed into particles having a mean diameter of less than about 2 cm, for example, by grinding or sawing. Milling can be performed using a hammer mill, low-temperature mill or shredder. Hikichigiri is a US patent
This can be done using Lickerin as described in 4,813,948 (Insley). Said tearing produces a microweb having a relatively dense core with fibers and fiber bundles extending therefrom. The core of the microfiber microweb is preferably in the range of about 0.05-4 mm, more preferably about 0.2-2 mm. Stretching fiber and / or
Alternatively, the fiber bundle preferably extends beyond the core to provide an overall diameter of preferably about 0.07-10 mm, more preferably about 0.1-5 mm.

The articles and containers of the present invention are formed by compressing particles of polyolefin microfibers, ie, compressing the microfiber microweb to at least about 20%, preferably at least about 30% solids. The solidity of an article or / container is calculated by the following equation.

% Solidity = density of compressed article × 100 / Z (density of component) × (weight ratio of component) When the solidity is less than about 30%, the shaped article is supported, ie plastic casing, fiberboard A box or metal outer casing may be required. Preferably, the polyolefin fibers are compressed to a solids of about 80% or less, more preferably about 70% or less. Approx. 80% solidity
In the case described above, the sorption properties and the impact absorbing properties of the shipping container may be insufficient. When the polyolefin fiber is provided as a microfiber microweb, the solidity of the article is most preferably about 40-50%, which is excellent because it can be drilled or milled into the desired shape. Provided is a material having improved sorption properties and shock absorbing properties.

Compression of the particles of polyolefin microfibers can be accomplished using conventional compression molding equipment, such as flash molding, or powder molding equipment at ambient conditions. Generally, a pressure in the range of about 2 to 25 MPa is sufficient to achieve the desired degree of solidity. When the particles are microfiber microwebs, a pressure in the range of about 5 to 10 MPa is preferably about 40 to 50 MPa.
% Solids are preferably used. Although the pressure is used to compress the microfiber particles to form the article of the present invention, there is no significant fusion of the microfibers and no reduction in the effective microfiber surface area.

The articles and containers of the present invention have excellent sorption properties.
Articles and containers are preferably at least about 0.5 / m ² /
Min, more preferably at least about 1.0 / m ² / min, and most preferably at least about 2.0 / m ² / min required yield Chakudo. Articles and containers are preferably at least about 0.25 cm
³ / cm ^3, more preferably at least about 0.40cm ³ / cm ^3, most preferably at an equilibrium adsorption of at least about 0.60cm ³ / cm ^3. Articles and containers are preferably at least about 0.15 cm
³ / cm ^3, more preferably of a centrifugal retention of at least about 0.20cm ³ / cm ^3.

The articles and containers of the present invention possess good mechanical properties. The tensile strength of the article or container material is preferably at least about 9 KPa, more preferably at least about 20 KP
a, most preferably at least about 50 KPa. Articles and compressive strain energy of the container material is preferably at least about 5 KJ / m ^3, more preferably at least about 20 kJ /
m ³ , most preferably at least about 40 KJ / m ³ .

The container of the present invention has excellent insulation. The container preferably has a thermal conductivity at a temperature of 76 ° C. of no more than about 1.5 × 10 ⁻⁴ cal / cm-sec- ° C., more preferably no more than about 1.0 × 10 ⁻⁴ cal / cm-sec- ° C.

The container of the present invention can serve as a container for storing and shipping materials under low temperature conditions when liquid nitrogen is absorbed. Preferably, the outside of the container is provided with insulation to reduce evaporation of the liquid.

Fine particles and fibrous materials are disclosed in U.S. Pat. No. 3,971,373 (Brau
n), Nos. 4,118,531 (Hauser) and 4,100,324 (Ander
webs of microfibrils formed as described in Son et al. and 4,429,001 (Kolpin et al.), or by mixing fines or fibrils with microfibrils that have been ground or torn prior to compression. It can be introduced into the compressed polyolefin microfibrous structure by introducing particulates or fibrous material therein. Preferably,
The microparticles are introduced into the microfibers as they form.

Particulate materials useful in the present invention are not limited to absorbent particulate materials, but include neutralizing particulate materials and catalytic materials. Preferably, the amount of microparticles incorporated into the compressed microfibrous structure is less than about 90% by weight, more preferably less than about 75% by weight.
% By weight, most preferably 50% by weight or less.

Useful absorbent particulate materials for hazardous aqueous liquids include high sorbent liquid sorbent particles, such as water-insoluble modified starch,
For example, sorbent fine particles described in U.S. Pat. No. 3,981,100 and a high molecular weight acrylic polymer containing a hydrophilic group can be mentioned. Particulate materials useful for sorbing liquids other than water in the sorbent are available from Dow Chemical Company, an alkylstyrene sorbent particle. For example, Imbiber Be
ads ^TM . Other sorbent particulate materials include wood pulp and activated carbon, which is particularly useful for absorbing the vapors emitted from hazardous materials.

Neutralizing particulate materials useful in the present invention include, for example, materials such as alumina, sodium carbonate, sodium bicarbonate, and calcium carbonate. Catalytic particulate matter that can be introduced into the compressed polyolefin microfibrous structure includes, for example, popcalite and silver. Biological entities such as enzymes or microbiological species that can catalyze the conversion of hazardous materials to harmless by-products can also be incorporated into the articles and containers of the present invention.

Preferably, the container of the present invention includes an outer shroud. The outer covering may be made of, for example, fiberboard, metal, or a thermoplastic material. A preferred outer wrapping material is a shrinkable thermoplastic film, well known in the art, which can be provided with an additional, impermeable layer to further ensure inclusion of hazardous materials.

The containers of the present invention can be molded and, optionally, milled or drilled into various shapes such that the packaging of the hazardous material can be safely stored or shipped in the container. The size of the container is preferably
If present, it is sized so that sufficient sorbent microfibrils and particulates are present to absorb, contain, or neutralize hazardous materials with some margin for safety.

FIG. 1 shows a preferred container 10 of the present invention that encloses a dangerous liquid bottle 12. The container 10 has a lower part 14 and a lid 16,
Each is formed of compressed polyolefin microfibers. Lid 16 has a protruding portion 18 that mates with cavity 22 in lower portion 14. A covering of thermoplastic shrinkable film 20 is provided around the compressed polyolefin microfibers.

FIG. 2 shows a container of the present invention used for storage of test tubes.
Shows 26. The container is preferably molded as a mass and then a hole 28 is drilled in the mass to accommodate the test tube.

FIG. 3 shows a container 30 used to contain a vial of dangerous liquid material. The container has a compressed polyolefin microfiber base 32 and a lid 34. Such a container is preferably molded as a mass and has a base hole 36
A hole 38 is formed in the mass to accommodate the vial 40.

The following examples further illustrate the invention,
The particular materials and amounts thereof in these examples, as well as the conditions and details, should not be construed to unduly limit the invention. In the examples, all parts and percentages are by weight unless otherwise specified.

The following test methods were used to characterize the molding materials of the present invention.

Required Sorption Degree Test A test sample of 4.45 cm (1.75 inch) diameter sorbent material is placed on a 25-50 μ porous plate in a filter funnel and placed at 1.0 KPa.
Of pressure was applied to the sample by a plunger that was able to move freely within the barrel of the funnel. Zero hydrostatic head deionized water was guided from the container to the upper surface of the perforated plate by a siphon mechanism, where the sample sorbed the water. Measure the initial linear velocity of absorbency / m
Reported at ² / min.

Equilibrium sorption A sample of the sorbent material was placed in a bath of deionized water and saturated for 24 hours. The sample was then removed from the bath and placed on an open mesh sieve for 10 minutes to drain excess water. The amount of water sorbed by the unit volume of material was measured and the equilibrium sorption was reported in cm ³ / cm ³ .

Centrifuge retention test Place a sample of the sorbent material saturated with deionized water at equilibrium (saturation time 24 hours) in a centrifuge tube, place it in a centrifuge in turn, and centrifuge the sample to 180 G Exposed for 10 minutes. The sample was removed from the centrifuge tube and the amount of water remaining in the sample was measured. Centrifuge retention values are reported by the volume of water retained per unit volume of material (cm ³ / cm ³ ).

Mechanical Properties - total surface area of the test specimens the tensile strength dog pawn type 66.8Cm ² and 25.
Mold to have a test area of 5 cm ² . The maximum tensile strength of the molded test specimen (width 2.5 cm, length 10.2 cm) was measured using an Instron tensile tester. ASTM F152−
Evaluation was performed according to 86 Method C using a crosshead speed of 1.0 cm / min.

Mechanical Properties-Evaluation of Compressive Stress / Strain Cylindrical specimens with a diameter of 4.4 cm were subjected to compressive stress using an Instron test apparatus incorporating a compression load cell. The distortion of the specimen for a given load is
Recording was performed using the loading speed evenly up to 9.5 KPa. The crosshead speed of the test equipment was 1.0 cm / min throughout the evaluation. Area under the strain energy stress / strain curve of the test specimen was determined by calculating the reported in KJ / m ^3.

Thermal conductivity The thermal conductivity analysis performed under ASTM F-433 was performed on a cylindrical sample of 5.1 cm in diameter and 1.3 cm in length, ca
Report in l / lm-sec- ° C.

Impact Energy Density Impact energy density was measured according to ASTM test method D-3331.

Shock Mitigation Efficiency Shock Suppression Efficiency is "Shock Suppressed"
Measured as described in Design, May 21, 1987. In this test, a 10 kg weight is dropped from various distances onto a given volume of material and the deceleration-time response is measured.

Surface area The surface area was measured using the BET nitrogen absorption method.

Carbon tetrachloride vapor adsorption A sample of the adsorbent material previously prepared for 4 hours at 100 ° C. in a convection filter was placed on a porous ceramic plate located 2 cm above the horizontal plane of carbon tetrachloride in a sealed dissection instrument containing carbon tetrachloride. Placed. The weight gain of the sample is determined gravimetrically after exposure to steam for 24 hours.

Example 1 Wente, Van A., "Ultra-fine thermoplastic fibers", meltblown microfiber webs using polypropylene resin (Dypro ^™ 50MFR, manufactured by Fina Oil & Chemical Co.), Industria
l Prepared as described in Enngineering Chemistry, Vol. 48, pp. 1342-1346. The fibers were sprayed with a surfactant solution (Aerosol ^™ OT, manufactured by American Cyanamid Co) at a rate of 2% surfactant supplied based on the weight of the fibers. The microfibers had an average diameter of about 6-8 microns. The web had a basis weight of 270 g / m ² , a density of 5.2 × 10 ^-2 g / cm ^3, a density of 5.7%, and a void volume of 18.1 cm ³ / g. The sorption properties of the web were tested. Result is required sorption degree 4.95
/ m ² / min, equilibrium sorption 0.66 cm ³ / cm ^3, and centrifuge retention 0.39Cm ³
/ cm ³ .

Use lickerin having a velocity of tooth density and 900rpm of microfibers 6.2 teeth / cm ² No. 4,813,948 (I
Microfiber microwebs having an average core diameter of 0.5 mm and an average microweb diameter of 1.3 mm were produced by tearing as described in N.S.

Place microfiber microweb (587g) in compression mold,
Compressed to 35% solids, 14.2 cm outer diameter, 8.0 cm inner diameter,
And a cylindrical container with top and bottom covers having a height of 14.6 cm and a diameter of each 14.2 cm and a thickness of 1.9 cm each. A glass jar (capacity 0.47) containing 460 cm ³ of mineral oil was placed in the container, covers were placed on both ends of the container, and the completed container was vacuum wrapped with 0.5 mm thick polyethylene film.

Containers are subject to the International Safety Transport Association Drop Test Procedure 1A for packaging products weighing less than 100 pounds (45 kg), subject to being dropped from a height of up to 60 inches without breaking glass jars. Used and tested for durability. The container was also tested for falling on concrete from a height of 30 feet without breaking the glass jar.

Containers without top cover were tested for absorbency.
The container cavity was filled with light mineral oil and its height was kept at the top of the cavity. At time intervals as shown in Table 1, oil is drained from the cavity, the container is weighed, and the cavity is then refilled with oil. The oil sorption rate and equilibrium sorption degree were measured. The data is shown in Table 1.

As can be seen from the data in Table 1, the container had an excellent sorption rate, sorbing close to 80% of the total volume within 15 minutes. The total sorption capacity of a container is about 1 to 1/2 times the weight of the container.

Examples 2 to 46 In Examples 2 to 46, compressed particulate polyolefin microfibers suitable for use in articles and containers of the present invention were prepared using the solid and microfibrous materials shown in Tables 2-4. Prepared. Uncompressed microfiber microweb material A was prepared according to the procedure of Example 1. Fine fiber material B
A web was prepared according to the procedure of Example 1. Then, run the web at 500rpm with a hammer mill (Champion Cho
pn Throw ^TM Shredder, Champion Products, Inc.,
), Mainly about 10mm in size, about 2-40 in size
mm of highly ground microfibril particles were produced. Material C
Was a flash spun polyethylene fiber having a diameter of about 1-5 microns and an average particle size of 1-6 mm (Tywick ^™ Hazardous Substance Pulp, New Pig Corp.).

Examples 2-16 In Examples 2-16, the fine solid polyolefin microfiber material was pressed using a hydraulic press to compress each sample to a nominal solidity of 30%, 40%, 50%, 60% and 70%. A sample for tensile strength test was formed. Table 2 shows compression thickness, recovery thickness (60 minutes after removal from the press), actual solidity and tensile strength.
Report to

As can be seen from the data in Table 2, increasing the solidity of the compressed polyolefin microfiber sample increased the tensile strength of the sample.

Examples 17-31 In Examples 17-31, 30%, 40%, 50%, 60% and 70% nominal of the particles of polyolefin microfibers were compressed using a hydraulic press to compress each sample. A solid compression test sample was formed. The compressed thickness, recovered thickness (after 60 minutes of removal from the press), actual solidity and strain energy are reported in Table 3.

As can be seen from Table 3, it shows that as the solidity of the compressed particles of polyolefin microfibers increases, the strain energy decreases and the material becomes stiffer as the void volume decreases.

Examples 32-46 In Examples 32-46, the particles of polyolefin microfibrous material were compressed and 30%, 40%, 50%, 60%, and 70% of the samples were compressed using a hydraulic press to compress each sample. Samples were formed for sorption and retention tests of nominal solidity. Fiber weight,
The compressed thickness, recovered thickness (after 60 minutes of removal from the press) and actual solidity are reported in Table 4. The equilibrium sorption, required sorption degree and centrifugation retention values for Examples 32-46 are reported in Table 5.

The data in Tables 4 and 5 demonstrate that both the equilibrium sorption and the required degree of sorption decrease as the void volume of the molding material decreases. The centrifugal retention remains essentially the same, despite indicating that the effective surface area of the material with respect to solidity does not decrease with increasing density.

Examples 47-50 and Comparative Examples C1 and C2 In Examples 47-50, meltblown microfiber webs were prepared and de-velocated as in Example 1 to form microfiber microwebs. Portions of the microfiber microweb were molded under various amounts of pressure as shown in Table 6.
The resulting polyolefin microfiber material is characterized along with a sample of meltblown microfibers prior to debrication (Comparative Example C1) and a sample of microfiber microwebs prior to compression (Comparative Example C2) and tested for equilibrium sorption with light mineral oil did. Table 6 shows the results.

As can be seen from the data in Table 6, as the molding pressure increases, the solidity increases and the equilibrium sorption decreases.

Examples 51-53 In Examples 51-53, compressed polyolefin microfiber particles were prepared as in Examples 48-50, characterized and tested for equilibrium sorption with water. Table 7 shows the results.

As can be seen from the data in Table 7, as the molding pressure increases, the solidity increases and the equilibrium sorption decreases.

Examples 56-58 and Comparative Examples C3-C6 In Examples 56-58, the compressed polyolefin microfiber material was replaced with fibrous materials A, B, as described for 40% nominal solids Examples 2-46. And C were prepared. Table 8 shows the compression thickness, the recovery thickness, and the actual solidity.
Each of the materials of Examples 56-58 was tested for its cushioning properties. Table 9 shows the impact energy density, peak acceleration, and impact relaxation efficiency. Urethane ester foam (Comparative Example C
3) Impact energy density and impact on various foam materials of US Pat. No. 4,584,822 including polystyrene foam (Comparative Example C4), polyethylene foam (Comparative Example C5) and low density polyurethane foam (Comparative Example C6) The mitigation efficiency is also reported in Table 9.

As can be seen from the data in Table 9, the material of the present invention, except for the low density polyurethane foam, provides better impact mitigation efficiency than the comparative foam material. Although the foams of Comparative Examples C3-C6 provide a slight cushioning effect, each material is substantially non-absorbable.

Example 59 A cylindrical container was prepared as in Example 1. The bottom cover was placed on top of the cylinder and a 0.5 mm thick layer of polyethylene was applied to the outer surface to integrate the cylinder and the cover to provide a liquid barrier. Liquid nitrogen was charged into the open container until 450 g had been absorbed and the thermocouple was placed in the open cavity.
2.5cm of the container which absorbed liquid nitrogen at the outside temperature of 21 ℃
Was placed in a second container of styrene foam having a wall thickness of The container was inverted after absorption to allow any free nitrogen to escape. Upside down,
The temperature of the open cavity of the container was monitored at room temperature, which was maintained at 21 ° C. Table 10 shows the resulting temperatures.

As can be seen from the data in Table 10, the nitrogen absorbed and retained on the container walls retains the initial temperature for at least 3 hours before it has boiled off.

Example 60 and Comparative Examples C7 and C8 60 g of activated carbon (PCB) with a total basis weight of 200 g / m ²
Microfiber webs containing meltblown microfibers using 30 × 140, Calgon Corp.) and 40% by weight polypropylene resin (Dypro 50MFR) were prepared in US Pat.
Prepared as described in 971,373 (Braun).
The web was de-velocated as described in Example 1 to form a microfiber microweb. The microweb (23 g) is then compressed in a mold having a diameter of 5.1 cm under a pressure of 8.4 MPa to obtain a material having a diameter of 5.2 cm and a thickness of 2.2 cm and having a solidity of 32% when calculated according to the following formula. Manufactured. Solidity = [density of molded article / {(density of carbon) (weight ratio of carbon) + (density of polypropylene) (weight ratio of polypropylene)}] × 100.

The molding material was then tested for carbon tetrachloride capture capacity. Activated carbon sample (Comparative Example C7) and thickness 2.7c
Example 2 using 27.4 g of microfiber microweb to obtain a material having a m, diameter of 4.5 cm and a solidity of 57%
A sample of the molding material without activated carbon prepared according to the procedure of Example 6 (Comparative Example C8) was also tested. Table 11 shows the results.

As can be seen from the data in Table 11, the activated carbon retains its sorption effectiveness when packed into a web of microfibers and then develocated and molded. This retention of effectiveness is a result of the open structure of the microfiber components and the usefulness of the activated carbon sorption surface even after molding.

Example 61 Compressed polyolefin microfiber particulate material was prepared as in Example 32 and tested for thermal conductivity. The thermal conductivity was 1.5 × 10 ⁻⁴ cal / cm · sec · ° C. at a temperature of 76 ° C.

Example 62 Compressed polyolefin microfiber particulate material was prepared as in Example 44 and analyzed for surface area. The surface area was 1.54 m ² / g. The surface area of the microfiber web used to prepare the microfiber microweb was also analyzed for surface area and found to be about 1.2 m ² / g. The fact that the surface area of the compressed polyolefin microfiber material was not significantly different from the surface area of the microfiber web,
This indicates that substantially no fiber bonding has occurred during the molding process.

Various modifications and alterations of this invention will be apparent to those skilled in the art without departing from the scope and spirit of this invention, and the invention is limited to those shown here for illustrative purposes. Should not be.

[Brief description of the drawings]

FIG. 1 is a perspective view of the container of the present invention. FIG. 2 is a perspective view of another container of the present invention. FIG. 3 is a perspective view of a further advanced container of the present invention.

Continuation of the front page (51) Int.Cl. ⁷ identification code FI // B29K 105: 12 (58) Investigated field (Int.Cl. ⁷ , DB name) B65D 81/113 B29B 11/12-11/16

Claims (5)

(57) [Claims] 1. A molded article comprising compressed particles of polyolefin microfibers and having a solidity of 20% or more and less than 80%. 2. The microfiber has a diameter of less than about 50 μm.
The molded article according to claim 1. 3. The compact of claim 1, wherein the compacted particles have an average diameter of less than about 2 cm. 4. A container for shipping and storing dangerous liquid substances, made of the molded article according to claim 1. 5. The process of claim 1 wherein: i) tearing or pulverizing the web of polyolefin microfibers to provide polyolefin microfiber particles; ii) feeding said microfiber particles to a mold. Iii) applying pressure to the microfibers to form a compact; iv) releasing the pressure; and v) removing the compact from the mold. The above process, which is sufficient to achieve a solidity of 20% or more and less than 80% when released.