KR101153530B1 - Uv resistant multilayered cellular confinement system - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates generally to polymeric celluar confinement systems that can be filled with soil, concrete, aggregates, earth material, and the like. In particular, the present invention relates to cellular limitation systems characterized by improved durability against damage caused by ultraviolet light, humidity, aggressive soils, and combinations thereof.

Description

UV resistant multi-layer cellular restriction system {UV RESISTANT MULTILAYERED CELLULAR CONFINEMENT SYSTEM}

Reference to Related Application

The present invention relates to a US patent application No. PRSI 200003, filed concurrently with the present invention, entitled "GEOTECHNICAL ARTICLES"; US Patent Application No. PRSI 200004, filed simultaneously with the present invention, entitled "HIGH PERFORMANCE GEOSYNTHETIC ARTICLE"; US Provisional Patent Application No. PRSI 200005, filed concurrently with the present invention, entitled "WELDING PROCESS AND GEOSYNTHETIC PRODUCTS THEREOF"; US Provisional Patent Application No. PRSI 200006, filed concurrently with the present invention, entitled "PROCESS FOR PRODUCING COMPATIBILIZED POLYMER BLENDS." These four patent applications are hereby incorporated by reference in their entirety.

The present disclosure generally relates to polymeric celluar confinement systems that can be filled with soil, concrete, aggregates, earth material, and the like. In particular, the present disclosure relates to cellular limitation systems characterized by improved durability against damage caused by ultraviolet light, humidity, aggressive soil, and combinations thereof.

Plastic soil reinforcement products, in particular, cellular confinement systems (CCSs), include soil, rock, sand, stone, peat, mud, concrete, aggregates and lipids supported by the cellular restriction systems (CCS). It is used to increase the load bearing capacity, stability and erosion resistance of geotechnical materials such as materials.

Cellular restriction systems (CCS) comprise a plurality of high density polyethylene (HDPE) in a characteristic honeycomb-like three-dimensional structure. The strips are welded to each other in separate locations to achieve this structure. The geotechnical material can be strengthened and stabilized in or by the cellular restriction system (CCS). The geotechnical material stabilized and reinforced by the cellular restriction system (CCS) is hereinafter referred to herein as geotechnical reinforced material (GRM). The surface of the cellular restriction system (CCS) increases friction with the geotechnically reinforced material (GRM) and reduces the relative motion between the cellular restriction system (CCS) and the geotechnically enhanced material (GRM). In order to be embossed.

The cellular limiting system (CCS) is the shear strength of the cell wall as a result of the hoop strength of the cell wall, the passive resistance of adjacent cells, and the friction between the cellular limiting system (CCS) and the geotechnically strengthened material (GRM). And strengthening the geotechnically strengthened material (GRM) by increasing robustness. Under load, the cellular limiting system (CCS) generates strong lateral limiting forces and wall friction of the soil-cell. This mechanism results in a bridging structure with high flexural strength and robustness. This bridging action improves the long-term load deformation performance of common particle filling materials and allows for a significant reduction of less than 50% in the thickness and weight of structural support elements. Cellular limiting systems (CCS) include road-based stabilization, branched plains, track tracks to stabilize track ballasts, wall preservation, geologically engineered materials (GRM) or plant protection and ramps. It can be used in load supporting situations such as and channels.

Hereafter, the term “high density polyethylene (HDPE)” refers to polyethylene characterized by a density greater than 0.940 g / cm ³ . The term medium density polyethylene (MDPE) refers to polyethylene characterized by a density of 0.925 g / cm ³ to 0.940 g / cm ³ . The term linear low density polyethylene (LLDPE) refers to polyethylene characterized by a density of 0.91 to 0.925 g / cm ³ .

The plastic walls of the cellular limiting system (CCS) can be damaged during service and use in the field by ultraviolet light, heat, and humidity (UHH). The damage results in brittleness, reduced flexibility, toughness, impact and puncture resistance, poor burst resistance and discoloration. In particular, the thermal damage to the cellular restriction system (CCS) is severe in hot fat on the planet. As used herein, the term "hot fat" refers to an area located at latitude 42 degrees on both sides of the equator and in particular along the desert belt. Hot regions include, for example, parts of North Africa, southern Spain, the Middle East, Arizona, Texas, Louisiana, Florida, Central America, Brazil, most of India, western China, Australia, and Japan. Hot areas are fats with temperatures above 35 ° C and constant sunlight for up to 14 hours each day. Dark surfaces of plastics exposed to direct sunlight can reach temperatures as high as + 90 ° C.

  Several industrial strategies have been applied to protect plastic walls from such damage by treating the polymers that make up the plastic walls. For dark colored products, ie black or dark gray products, carbon black can be introduced to block ultraviolet radiation and disperse free radicals. However, one disadvantage resulting from the use of carbon black is its aesthetic appearance. Black Cellular Restriction System (CCS) is not preferred for use of Black Cellular Restriction Systems (CCS) when this cellular restriction system (CCS) is part of the view structure. A second disadvantage is that black cellular restriction systems (CCSs) tend to absorb and heat sunlight. High density polyethylene (HDPE) and medium density polyethylene (MDPE) tend to creep when heated to 40-50 ° C or higher. As a result, creep can be accelerated particularly severely, especially at welds and thinner wall structures, leading to structural defects.

Cellular restriction systems (CCS) are usually anchored or anchored to a geotechnically reinforced material (GRM) by wedges, tendons, bars or anchors. This immobilization is particularly critical when the cellular restriction system (CCS) is used to reinforce the slope. The wedges, tendons, bars or anchors are usually made of iron and can be heated by direct sunlight to temperatures that can exceed 60-85 ° C. The high conductivity of iron also transfers heat to the buried portion of the cellular restriction system (CCS). These anchor points experience severe stress concentrations. Without UV, heat and humidity (UHH) protection, these anchor points can crack before any major damage is observed in the remainder of the cellular restriction system (CCS).

In addition, stresses occur in the welding between the strips making up the cellular limiting system (CCS). The stress is such that during installation, a person walks over the Cellular Restriction System (CCS) and before and during the charge with the geotechnically reinforced material (GRM) or with the geotechnically reinforced material (GRM) to fill the cell. Occurs from compression when overlying the cellular limiting system (CCS). In addition, the geotechnically reinforced material (GRM) may expand when it is damp or water already in the geotechnically reinforced material (GRM) freezes in cold climates. In addition, the geotechnically reinforced material (GRM) has a coefficient of thermal expansion (CTE) about 5-10 times lower than the high density polyethylene (HDPE) used to make the strips; This creates stress along the cellular limiting system (CCS) wall, in particular along the weld.

Some cellular restriction systems (CCS) are pigmented to similarly shade the geotechnically reinforced material (GRM) they support. This is the product of light pigments and cellular restriction systems of conventional shades, such as soil-like colored CSS, turf-type pigment cellular restriction system (CCS), and peat-type pigment cellular restriction system (CCS). (CCS).

For cellular restriction systems (CCS), certain additives (ie different from carbon black) are required to maintain these properties for cycles of 20 years or more. The most effective additives are benzotriazoles and ultraviolet absorbers such as radical scavengers and antioxidants such as benzophenones, hindered amine light stabilizers (HALS). Usually, a "package" of one or more additives is provided in the polymer. The additive is usually introduced into the polymer as a master batch or holkobatch, dispersion and / or solution additive of the polymer or wax carrier.

The amount of additive in the polymer used to make the cellular restriction system (CCS) depends on the life time required for the cellular restriction system (CCS). In order to provide a protection of about five years, the amount of additive required is less than that required for a period of more than 10 years. Because additives are hung from the polymer over time due to evaporation or hydrolysis, the substantial amount of additive required for protection over a longer period of time is 2 to 10 times more than the amount required for short cycles of protection. . In other words, the amount of additive added to the polymer must compensate for jamming, evaporation and hydrolysis, and therefore must be significantly greater than the amount required for short cycle protection. In addition, as the heat and moisture where the cellular restriction system (CCS) is used increases, more additives need to be added to the polymer to maintain its protection level.

The additives are generally very uniformly dispersed or dissolved throughout the entire cross section of the polymer strip used to make the cellular restriction system (CCS). However, the largest interaction between the additive and the agent causing ultraviolet, heat and humidity (UHH) damage occurs at the outermost volume of the polymer strip or film, i.e. from 10 to 200 micrometers (μm). do.

Some hot climates, especially tropical ones, have high humidity and heavy rain. The combination of high humidity and heat accelerates the hydrolysis, extrusion and evaporation of the protective additive from the polymer strip. Most important is the loss of ultraviolet absorbers, such as benzophenone and benzotriazole, and heat stabilizers—particularly hindered amine light stabilizers (HALS). Once the additive is lost, the polymer strip is easily attacked and its properties deform quickly.

U. S. Patent No. 6,953, 828 describes a thin film comprising a geotextile barrier stabilized against ultraviolet radiation. The patent relates to polypropylene, which relates to very low density polyethylene composites that are effective in thin films, but are not practical for cellular restriction systems (CCS). Polypropylene is very brittle at temperatures below zero degrees. Very low density polyethylene is very weak for use in cellular restriction systems (CCS) because it tends to creep at moderate loads. Once the cellular restriction system (CCS) is creep, the integrity of the cellular restriction system (CCS) and the geotechnically strengthened material (GRM) is disrupted and structural performance is irreversibly compromised. In addition, polypropylene requires large provision of additives to overcome jamming and hydrolysis; This results in an uneconomical polymer.

U. S. Patent No. 6,872, 460 describes a bilayer polyester film structure wherein a UV absorber and stabilizer are introduced in one or two layers. Various grades of polyester are generally applicable for geo-grid, a two-dimensional product used to reinforce soils, such as matrices of reinforced tendon. Geo-grids are usually buried underground and are therefore not exposed to ultraviolet radiation. In contrast, cellular restriction systems (CCS) are three dimensional and are typically partially exposed to the ground level and thus to ultraviolet light. Polyesters generally have poor impact and puncture resistance in their stiff surroundings and especially when in direct contact with soil media such as medium to low hydrolysis resistance at temperatures below zero (especially concrete and calcined soil). And, in terms of overall cost, they are not suitable for use in cellular restriction systems (CCS). In addition, polyester requires a large provision of additives to overcome filtering and hydrolysis; This results in an uneconomical polymer.

For thin polymer strips (characterized by a thickness of about 500 micrometers (μm) or less), the substantial amount of additive required is generally matched to the theoretically calculated amount. However, in thicker strips (thickness greater than about 750 micrometers (μm)-usually with structural and geotechnical reinforcement elements-for example cellular restriction systems (CCS)), the actual total amount of additives required is generally This is much more than the theoretically calculated amount. For high performance Cellular Limiting Systems (CCS) with thicknesses greater than about 1.5 mm, strength, toughness, flexibility, tearing, puncture resistance, and low temperature retention are required, and the total amount of additives required is theoretically calculated. 5 to 10 times more than required. Ultraviolet, heat and humidity (UHH) -protective additives are very expensive relative to the price of the polymer. Thus, most manufacturers provide additive additives that more closely match the lower (ie, minimum) theoretically calculated amounts of grant levels that are required for longer protection periods of 50 years or longer. In addition, high density polyethylene (HDPE) and medium density polyethylene (MDPE) provide poor barrier properties against the entry of harmful ions and molecules into the polymer and the trapping and evaporation of additives from the polymer. For this reason, in practice, most manufacturers do not currently guarantee the long term robustness of thick polymer strips. Cellular restriction systems (CCS) currently use hindered amine light stabilizers (HALS) and ultraviolet absorbers in amounts of 0.1 to 0.25 wt% (weight percent) dispersed through the polymer strip.

Another feature associated with outdoor robustness is the type of polymer used for cellular restriction systems (CCS). The choice of the correct polymer for this application is a tradeoff between economics, namely the price of the raw material and the long term robustness. In this respect, polyethylene (PE) is one of the most popular materials due to its balance of price, strength, flexibility at temperatures as low as minus 60 ° C and ease of processing in standard extrusion equipment. In addition, polyethylene is suitably resistant to ultraviolet rays and heat. However, without additives, the polyethylene deteriorates within a year to an unacceptable degree for normal use. Even when used very stably, PE is still inferior to higher ultraviolet resistant polymers such as ethylene-acrylic ester copolymers and terpolymers.

On the other hand, polymers exhibiting higher ultraviolet and heat resistance, such as acrylic and methacrylic ester copolymers and terpolymers, in particular ethylene-acrylic ester copolymers and terpolymers, are viewed in terms of UV, heat and humidity (UHH) resistance. When it is very suitable for a typical application. However, their relatively high cost and very low molecular and strength characteristics limit the application of a wide range of cellular restriction systems (CCS).

Cost-effective UV, heat and humidity (UHH) -resistant polymer strips, and cellular restriction systems (CCS) comprising them, in particular geotechnologically enhanced material (GRM) type optical pigment strips and their cellular restriction systems (CCS) It is required to provide. These cellular limiting systems (CCS) are resistant to harsh conditions, in particular in outdoor applications, in dry areas, in tropical and subtropical areas to temperatures in the Arctic, and have a useful service life of more than 50 years.

This disclosure relates to geotechnical products, in particular cellular restriction systems (CCS), which exhibit high robustness for at least two year cycles with respect to ultraviolet heat and humidity. In certain embodiments, the cellular restriction system (CCS) exhibits such robustness for at least 10 years. In another particular embodiment, the cellular restriction system (CCS) exhibits robustness of at least 20 years and up to 100 years. Robustness means free from chalking or cracking and retention of primary colors, surface integrity, strength, molecular retention, elongation to break, puncture resistance, creep resistance and weld strength.

In an exemplary embodiment, the cellular restriction system (CCS) comprises a plurality of polymer strips. Each polymer strip includes at least one inner polymer layer and at least one outer polymer layer. The at least one outer polymer layer exhibits greater resistance to ultraviolet light, humidity or heat (UHH) than the at least one inner polymer layer. Each polymer layer comprises at least one kind of polymer. The at least one outer polymer layer also includes a UV absorber or hindered amine light stabilizer (HALS). The ultraviolet absorber blocks and prevents harmful ultraviolet rays from penetrating into at least one inner polymer layer. The hindered amine light stabilizer (HALS) deactivates the diffusion of harmful radicals generated in the outer layer into the inner layer of the polymer strip. At least one outer polymer layer comprises (a) an ethylene-acrylate polymer and (iii) a high density polyethylene (HDPE) or (ii) a medium density polyethylene (MDPE); And (b) a polymer mixture of (i) an ultraviolet absorber or (ii) a hindered amine light stabilizer (HALS). Ethylene-acrylate polymers include ethylene-acrylic acid ester copolymers and terpolymers; And ethylene-methacrylic acid ester copolymer and terpolymer.

In another embodiment, the polymer layer comprises an additive selected from the group consisting of antioxidants, pigments and dyes.

In yet another embodiment, the at least one polymer layer can include a filler. In certain embodiments, the filler has a higher thermal conductivity than the polymer of the polymer layer.

In another embodiment, at least one layer of the polymer strip comprises a pigment or a dye. Preferably, the layer has a color similar to a geotechnically reinforced material (GRM) supported by a cellular restriction system (CCS). Preferably, the color is not black or dark grey.

The cellular restriction system (CCS) can be used to reinforce the geotechnically reinforced material (GRM).

Other cellular restriction systems (CCS) and apparatus are also described. Also provided are methods of making and using such polymeric layers and / or cellular restriction systems (CCS). These and other embodiments are described in more detail below.

The following is a brief description of the drawings of the present invention, which is for the purpose of illustrating the exemplary embodiments described herein but not for the purpose of limiting it.

1 is a perspective view of a single layer cellular restriction system (CCS).

2 is a perspective view of a cell including a geotechnically strengthened material (GRM).

3 is a perspective view of a cell comprising a geotechnically reinforced material (GRM) and wedges.

4 is a perspective view of a cell including tendons.

5 is a perspective view of a cell including tendons and lockers.

6 is a perspective view of an exemplary embodiment of a cell that includes a reinforced wall portion.

7 is an illustration of a polymer strip of the cellular restriction system (CCS) used in the present disclosure.

The following detailed description is provided to enable any person skilled in the art to make and use the embodiments described herein, and also to set the best mode for carrying out these embodiments. However, various modifications are apparent to those skilled in the art and should be considered to be within the scope of the present invention.

A more complete understanding of the components, processes, and apparatus described herein may be made by reference to the accompanying drawings. These drawings are only schematically shown on the basis of the convenience and ease of presentation of the invention, and therefore the intention is to indicate the size and size of the device or its components and / or to limit or limit the scope of the exemplary embodiments. no.

The present invention relates to a cellular restriction system (CCS) comprising a plurality of polymer strips and having a long term durability for use in outdoor applications. Each strip includes at least one outer polymer layer and at least one inner polymer layer. The outer polymer layer has higher UV, heat and humidity (UHH) resistance than the inner polymer layer. In particular, the outer polymer layer has higher resistance to ultraviolet light, humidity or heat than pure high density polyethylene (HDPE). The term “pure high density polyethylene (HDPE)” refers to any high density polyethylene (HDPE) that is received from the reactor prior to mixing with any UV absorber or hindered amine light stabilizer (HALS) additive. It should be noted that any polymer from the reactor generally already contains 200-1000 ppm antioxidant.

1 is a perspective view of a single layer cellular restriction system (CCS). The cellular restriction system (CCS) 10 includes a plurality of polymer strips 14. Adjacent strips are glued together by separate physical joints 16. Such bonding may be carried out by bonding, stitching or welding, but generally by welding. The portion of each strip between the two joints 16 forms the cell wall 18 of each cell 20. Each cell 20 has a cell wall made from two different polymer strips. The strips 14 are glued together to form a honeycomb pattern from multiple strips. For example, the outer strip 22 and the inner strip 24 are glued together by physically spaced spaced 16 jointly along the length of the strips 22 and 24. The pair of inner strips 24 are glued together by physical joints 32. Each joint 32 is between two joints 16. As a result, when the plurality of strips 14 are stretched in a direction perpendicular to the plane of the strips, the strips are bent in a sinusoidal pattern to form a cellular restriction system (CCS) 10. At the edge of the cellular restriction system (CCS) where the ends of the two polymer strips 22, 24 meet, an end weld 26 (also considered a joint) stabilizes the two polymer strips 22, 24. A short distance from the end 28 to form a short tail 30.

The cellular restriction system (CCS) 10 may be reinforced and secured to the ground in at least two different ways. An opening 34 may be formed in the polymer strip such that the opening shares a common axis. Tendon 12 may then extend through the opening 34. The tendon 12 enhances its stability by acting as a continuous, integrated anchoring member that strengthens the cellular restriction system (CCS) 10 and prevents unwanted displacement of the cellular restriction system (CCS) 10. Tendons can be used in channels and sloped applications to provide additional stability to gravity and hydrodynamic forces, and lower layers or natural hardened soil / rock are required when preventing the use of stakes. In addition, the wedge 36 may be used to anchor the cellular restriction system (CCS) 10 to the foundation upon which it is based, for example, applied to the ground. The wedge 36 is inserted into the base at a sufficient depth to provide an anchor. The wedge 36 can have any shape known in the art (ie, “wedge” is about action, not about shape). As shown, the tendons 12 and wedges 36 are simple iron or steel rebars cut to suitable lengths. They may also be formed of polymeric materials. These may be formed of the same composite as the cellular restriction system (CCS) itself. It may also be useful if the tendons 12 and / or wedges 36 have greater stiffness than the cellular restriction system (CCS) 10. A sufficient number of tendons 12 and / or wedges 36 are used to strengthen / stabilize the cellular restriction system (CCS) 10. It is important to recognize that tendons and / or wedges should always be positioned relative to the cell wall, not relative to the weld. Positioning tendons or wedges relative to the weld increases the likelihood of the weld failing, since tendons and / or wedges have high loads concentrated in small areas and the welds are at very weak points in the cellular limiting system (CCS). .

In addition, additional openings 34 may be introduced into the polymer strip, as described in US Pat. No. 6,296,924. These additional openings increase frictional interlock by up to 30% with geotechnically reinforced material (GRM), and root lock-up with the plant system as the plant roots grow between the cells 20. It improves root lock-up with vegetated systems, improves lateral drainage through the strip to give better performance in saturated soils, and promotes a good soil environment. Reduced equipment and long term maintenance costs can also be incurred. And, this cellular restriction system (CCS) is lighter and easier to handle compared to a cellular restriction system (CCS) with soil walls.

2 is a perspective view of a single cell 20 including a geotechnical reinforcing material (GRM). The cell 20 is shown to appear when the cellular restriction system CCS is positioned over a slope (indicated by arrow A), thereby retaining the geotechnically strengthened material (GRM) retained in the cell 20. ) Is substantially horizontally seated (ie flat to the ground), and the cell wall 14 of the cellular restriction system (CCS) 10 is connected to the slope A on which the cellular restriction system CCS is located. It is substantially perpendicular to. Since the cell wall 14 is not aligned horizontally with the geotechnically reinforced material (GRM), the geotechnically reinforced material (GRM) is substantially seated on the down-slope cell wall, and the "empty area". (empty area) "remains on the up-slope cell wall.

The cell wall 14 is subjected to forces F1 and F2. As a result of this slope, the force F1 (generated by the weight of the geotechnically strengthened material (GRM)) and force F2 (generated by the empty area of the adjacent down-slope cell) are not balanced. Do not. Force F1 is greater than force F2. This unbalanced force causes stress in the joint 16. In addition, the geotechnically strengthened material GRM generates a separation force F3 relative to the joint 6. This separation force arises from the mass and natural forces of the geotechnically strengthened material (GRM). For example, the geotechnically reinforced material (GRM) will expand because it retains moisture during the humid period. In addition, the geotechnologically strengthened material (GRM) will expand and contract, for example, from repeated ice-thaw cycles of water retained in the cell 2. This points to the importance of strong welds in each joint 16.

3 is a perspective view of a single cell 20 that includes a geotechnically reinforced material (GRM) and wedges 36. The wedge 36 applies an additional force F4 over the up-slope cell wall to help balance the forces on the cell wall 14. The additional force is applied over the local portion of the up-slope cell wall, which would damage the cell wall if it is not strong enough and there is no creep-resistance.

4 and 5 are perspective views of a single cell 20 including tendons 12. As described above, the tendon 12 extends through the opening 34 of the strip 14 and stabilizes the cellular limiting system (CCS) 10, especially in situations where the wedge 36 is not available. It is used to make. In addition, stress is generated locally in the strip 14 around the opening 34. For example, the tendon 12 may have a different CTE than the strip 14. If the strip 14 has an opening 34 but no tendons 12 are used, geologically reinforced material (GRM) or water / ice can also inflate the opening 34, Inflation increases the stress and can damage the integrity of the strip 14. As shown in FIG. 5, the locker 38 can be used to disperse the stress over a larger area, but the stress still exists. The use of the locker 38 provides additional protection against long term failures.

6 is a perspective view of an exemplary embodiment of a cell that includes a reinforced wall portion. Wedges 36 are located inside the cell 20. As described with reference to FIG. 3, the wedge 36 exerts additional force on a local portion of the up-slope cell wall and can damage the cell wall that is not sufficiently strong and does not have creep resistance. In an exemplary embodiment of the present invention, a reinforced wall portion 40 having a larger width than the wedge 36 is provided between the wedge 36 and the up-slope cell wall. As with the locker 38, the reinforced wall portion 40 distributes stress over a larger area of the cell wall. In one embodiment, the reinforced wall portion 40 extends over the upper edge of the wall, collapses below the farther side of the wall, further increasing the strength of the overall wedge-contact of the wall. In another embodiment, the reinforced wall portion 40 may also have an opening 34 to accommodate the use of the tendon 12.

In one embodiment, the reinforced wall portion 40 is attached to the wall by a suitable adhesive, for example a pressure sensitive adhesive or a curable adhesive. In another embodiment, the reinforced wall portion 40 may be attached directly to the wall in situ by welding operations, in particular by ultrasonic welding or stitching. The reinforced wall portion 40 is made of any suitable material. In a particular embodiment, it is made of the same material as the cell wall. If desired, the reinforced wall portion 40 may also be more rigid than the wall to accommodate more stress.

7 is a diagram of an exemplary polymer strip for use in the cellular restriction system (CCS) of the present invention. The polymer strip 200 includes at least one outer polymer layer 210 and at least one inner polymer layer 220. Here, a polymer strip having two outer polymer layers 210 is shown. Ultraviolet absorber 23 or hindered amine light stabilizer (HALS) 240 is dispersed within at least one outer polymer layer 210.

At least one outer polymer layer of the polymer strip comprises a UV absorber or a hindered amine light stabilizer (HALS). The ultraviolet absorber may be an organic ultraviolet absorber, such as a benzotriazole ultraviolet absorber or a benzophenone ultraviolet absorber. In addition, the ultraviolet absorbent may be an inorganic ultraviolet absorbent. The at least one outer polymer layer may comprise additional additives. The additive is selected from the group consisting of heat stabilizers, antioxidants, pigments, dyes and carbon blacks.

The polymer strip may comprise one or more outer polymer layers. In a particular embodiment, the polymer strip comprises a first outer polymer layer and a second outer polymer layer. The inner polymer layer lies between the first outer polymer layer and the second outer polymer layer. Each outer polymer layer comprises a greater number of additives than the inner polymer layer. In another embodiment, the polymer strip includes a first outer polymer layer and a second outer polymer layer. One outer polymer layer comprises a higher concentration of ultraviolet absorber and hindered amine light stabilizer (HALS) additive than the other outer polymer layer.

In another embodiment, the polymer strip is a single layer strip.

The component of the additive in the outer polymer layer is sufficient to provide protection to the polymer strip for a period of 2 to about 100 years. Herein, the term "about" refers to a range that is changed to a value 20% lower or higher than a predetermined value by "about". In certain embodiments, the amount of additive provides sufficient protection for the polymer strip for at least two year cycles. In an additional embodiment, the amount of additive provides sufficient protection for the polymer strip for at least five year cycles. In a further particular embodiment, the amount of additive provides sufficient protection for the polymer strip for at least 20 and 50 years, regardless of humidity, temperature and ultraviolet intensity. The term "sufficient protection" means that (i) the color and shade of the polymer strip and (ii) the original color, dark blue, or mechanical properties of the polymer strip for at least 50%, for a period of 2 to 100 years. Refers to the ability of the polymer strip to retain. Preferably, the polymer strip retains at least 80% of its original color, dark blue or mechanical properties.

The outer polymer layer comprises an ultraviolet absorber. In certain embodiments, the ultraviolet absorber is organic and is, for example, commercially available benzotriazole or benzophenone, such as Tinuvin ™ manufactured by Ciba and Cyasorb ™ manufactured by Cytec. The outer polymer layer may also include only hindered amine light stabilizers (HALS) or together with ultraviolet absorbers. Hindered amine light stabilizers (HALS) are molecules that provide long-term protection against the degradation caused by free radicals and light. In particular, hindered amine light stabilizers (HALS) do not contain phenolic groups. Their limited factor is the rate at which they are filtered out or hydrolyzed. The organic ultraviolet absorber and hindered amine light stabilizer (HALS) are present in an amount of about 0.01 to about 2.5 wt%, based on the total weight of the layer.

In addition, the outer polymer layer may comprise an inorganic ultraviolet absorber. In certain embodiments, the ultraviolet absorbent has a solid particle form. Solid particles are hardly soluble in polymers and water and have little volatility and therefore do not tend to move out of or escape from the layer. The particles may be micrometer-particles (eg, about 1 to about 50 micrometers in average diameter), sub-micrometer particles (eg, about 100 to about 1000 nanometers in average diameter), or nanoparticles ( For example, an average diameter of about 5 to about 100 nanometers). In certain embodiments, the ultraviolet absorbents comprise inorganic ultraviolet absorbing solid nanoparticles. Unlike organic UV absorbers which are soluble in the polymer and have fluidity even at high molecular weights, inorganic UV absorbers are substantially non-flowable and thus have very high resistance to filtering and / or evaporation. In addition, ultraviolet absorbing solid nanoparticles are transparent in the visible spectrum and are distributed very uniformly. Thus, they do not affect the color or shade of the polymer and provide protection. Solid particles are also very insoluble in water and improve the firmness of the polymer. In certain embodiments, the ultraviolet absorbing nanoparticles comprise a material selected from the group consisting of titanium salts, titanium oxides, zinc oxides, zinc halides and zinc salts. In certain embodiments, the ultraviolet absorbing nanoparticles are titanium dioxide. Examples of commercially available ultraviolet absorbing particles include SACHTLEBEN ™ Hombitec RM 130F TN manufactured by Sachtleben, ZANO ™ zinc oxide manufactured by Umicore, NanoZ ™ zinc oxide manufactured by Advanced Nanotechnology Limited, and Degussa. AdNano Zinc Oxide ™ manufactured by The ultraviolet absorbing particles may be present in an amount of about 0.01 to about 85 wt% per weight of the polymer layer. In certain embodiments, the inorganic ultraviolet absorbent particles are present from about 0.1 wt% to about 50 wt% based on the total weight of the polymer layer. In another particular embodiment, the polymer layer comprises an inorganic ultraviolet absorber, a hindered amine light stabilizer (HALS), and an optional organic ultraviolet absorber.

In some specific embodiments, the inner polymer layer does not include any organic UV absorbers, inorganic UV absorbers, or hindered amine light stabilizers (HALS) additives. In another particular embodiment, the inner polymer layer may comprise an organic UV absorber and a hindered amine light stabilizer (HALS) together in an amount greater than 0 and about 0.5 wt%, based on the total weight of the layer. In addition, the inner polymer layer may comprise an inorganic ultraviolet absorber in an amount of 0 to about 0.5 wt% based on the total weight of the layer.

Any layer may further comprise an antioxidant. Specific antioxidants that may be used include hindered phenols, phosphites, phosphates and aromatic amines.

Any layer can also include pigments or dyes. Any suitable pigment or dye may be used that does not seriously affect the desired properties of the entire polymer strip. In certain embodiments, at least one layer of the polymer strip (typically the outer polymer layer) is pigmented to be similar in color to the geotechnically reinforced material (GRM) supported by the polymer strip. In general, the color may be any color other than black or dark gray, especially any color other than gray scale. The colored polymer layer need not be uniform in color; In addition, any color pattern (such as camouflage) can be considered. In certain embodiments, the polymer strips may have a distinct color, such as red, yellow, green, blue or mixtures thereof and mixtures thereof with white or black as described by CIELAB color standards. Good combinations of color and shade are brown (soil-like), yellow (sand-like), green (glass-like), brown and gray (peat- like), off-white (aggregate), light gray (concrete), green (glass), and stains, spots, grains, dots, or marble It has a multicolored appearance that is like-like. This color has a practical feature that allows the cellular restriction system (CCS) to be applied and used in what is visible (ie, not embedded or covered with a filling material). For example, the Cellular Restriction System (CCS) can be used on a terrace where the outer layer becomes visible, but can be of a color that is compatible with the environment. In another specific embodiment, the polymer strip comprises a pigment or dye, but does not include carbon black. In general, for this application, carbon black is considered as an ultraviolet absorber rather than a pigment.

The polymer layer may also include filler. The polymer layer may comprise about 1 to 70 wt% of filler based on the total weight of the polymer layer. In another embodiment, the polymer layer comprises about 10 to about 50 wt% filler or about 20 to about 40 wt% filler, based on the total weight of the polymer layer.

The filler may be in the form of fibers, particles, flakes or whiskers. The filler may have an average particle size of about 50 micrometers (μm) or less. In another embodiment, the filler has an average particle size of about 30 micrometers (μm) or less. In another embodiment, the filler has an average particle size of about 10 micrometers (μm) or less.

Some materials may act as fillers. In some embodiments, the filler is metal oxide, metal carbonate, metal sulfate, metal phosphate, metal silica salt, metal borate, metal hydroxide, silica, silica salt, aluminate, aluminosilicate, fiber, whisker , Industrial ash, concrete powder or cement and kenaf, hemp, flax, ramie, sisal, newsprint fiber, paper mill sludge, sawdust, wood Powder, carbon, aramid or mixtures thereof.

In a further particular embodiment, the filler is a mineral selected from the group consisting of calcium carbonate, barium sulfate, dolomite, alumina trihydrate, talc, bentonite, kaolin, ulastonite, clay and mixtures thereof.

In addition, the filler may be surface treated to improve compliance with the polymer used in the polymer layer. In certain embodiments, the surface treatment is a size agent selected from the group consisting of fatty acids, esters, amides and salts thereof, silicone containing polymers and oligomers, and organometallic composites such as titanates, silanes and zirconates (sizing agent) or binder.

In a further particular embodiment, the filler has a higher thermal conductivity than the polymer of the polymer layer. In general, in a polymer layer having inferior thermal conductivity, the temperature of the polymer layer can be significantly increased for air near the hot day from a combination of convection and direct solar absorption (ie, the polymer layer is above the air temperature). Will be higher than 30 ℃). If the polymer layer has high thermal conductivity, its temperature will only increase slightly with respect to the temperature near it (ie, about 1 ° C. to about 30 ° C. or more relative to air temperature). This increased temperature can accelerate polymer degradation due to Arrhenius-type acceleration kinetics and accelerate evaporation, hydrolysis and / or entanglement of additives. Most polymers, especially medium density polyethylene (MDPE) and high density polyethylene (HDPE), have poor thermal conductivity, so using these polymers has a negative impact on the lifetime of geotechnical products, particularly cellular restriction systems (CCS). Surprisingly, it has been found that when mineral fillers are mixed into such polymers, the thermal conductivity and thermal capacity of the polymers are increased. This significantly lowers the rate of thermal acceleration degradation, prolonging its lifetime and resulting in greater stability against UV-induced degradation. In addition, improved thermal conductivity tends to improve creep resistance under mechanical loads and combinations of ultraviolet, heat and humidity (UHH). Improved thermal conductivity is very important for geotechnical applications in fats where the temperature above the surface of the cellular restriction system (CCS) exceeds 70 ° C. Typically, hot regions located between 42 degrees north latitude and 42 degrees south latitude have this extreme temperature. In addition, this generally reduces degradation following Arenius's first acceleration kinetics. In certain embodiments, the polymer layer comprises a filler having a high thermal conductivity selected from the group consisting of metal carbonates, metal sulfates, metal oxides, metals, metal coated minerals and oxides, aluminosilicates and mineral fillers.

The added mineral filler also lowers the CTE of the polymer. Whiskers and fibers are most effective at lowering CTE. The introduction of mineral fillers into the polymer layer improves the processing quality of the layer. The presence of fillers in the metal lowers heat built-up by reducing torque during melt kneading, extrusion and molding. This is particularly important in melt kneading operations, which are heat generating processes that can degrade polymers. Surprisingly, when filler is introduced, less mechanical energy is required for melt kneading per unit of mass of the compound compared to unfilled high density polyethylene (HDPE) or medium density polyethylene (MDPE), thus increasing the relative power per unit power. And heat generation in the composite along the extruder is reduced. In addition, the resistance to shear and extrusion during synthesis is reduced compared to only high density polyethylene (HDPE). As a result, smaller gels are generated, resulting in smaller degradation of the polymer. This point produces a thinner strip under the same torque of the extruder and shows an increased output rate when measured in units of time.

In addition, when the polymer layer comprises a mineral filler and an ultraviolet absorber or hindered amine light stabilizer (HALS), it is found that there is a synergistic effect that the loss rate and decomposition rate of the ultraviolet absorbent or hindered amine light stabilizer (HALS) are reduced. It became. This is believed to be due to the low heat generation in the polymer layer due to the improved thermal conductivity imparted by the mineral filler.

The polymer layer may further comprise barrier particles. Barrier particles are inorganic particles having high barrier properties. The term "barrier properties" means: (1) reducing the diffusion rate of additives from the polymer layer into the surrounding environment; (2) reducing the diffusion rate of hydrolysing agents such as water, protons and hydroxyl ions from the ambient environment into the polymer layer; And / or (3) the ability of inorganic particles to reduce the production / mobility of free radicals and / or ozone within the polymer layer. The main source of additive loss during the lifetime of the polymer strip is due to diffusion, washing, hydrolysis or evaporation. The diffusion or decomposition of such additives depends, among others, on molecular weight, backbone structure, miscibility in the polymer matrix, presence of ions and temperature. Thus, improving the barrier properties of the polymer strip improves the robustness of the polymer strip. Preferably, the barrier particles are nanoparticles. In certain embodiments, the barrier particles are selected from the group consisting of clays, organo-modified clays, nanotubes, metal flakes, ceramic flakes, metal coated ceramic flakes and glass flakes. Preferably, the barrier particles are flakes that maximize the surface area per unit mass. The polymer layer containing barrier particles is characterized by a low filtering, evaporation and hydrolysis rate of the additive, compared to the layer without barrier particles. The barrier particles may be present in an amount of about 0.01 to about 85 wt% by weight of the polymer layer. In more particular embodiments, the barrier particles are imparted from about 0.1 to about 70 wt% of the polymer layer. The permeability of the polymer layer to molecules having a molecular weight lower than about 1000 Daltons should be at least 10 percent lower compared to polymer strips without barrier particles as the same composite. The permeability of the polymer layer to molecules with molecular weight lower than about 1000 Daltons should be at least 25 percent lower compared to polymer strips made from high density polyethylene (HDPE) without barrier particles.

As before, each polymer layer comprises a polymer. In certain embodiments, the polymer is selected from high density polyethylene (HDPE) and medium density polyethylene (MDPE). In another embodiment, the polymer itself has improved ultraviolet, heat and humidity (UHH) resistance properties compared to pure polyethylene. Such polymers include (iii) ethylene-acrylic acid ester copolymers and terpolymers; (Ii) ethylene-methacrylic acid ester copolymers and terpolymers; (Iii) acrylic ester copolymers and terpolymers; (Iii) fatty polyesters; (Iii) fatty polyamides; (Iii) fatty polyurethanes; Mixtures thereof; And a mixture having at least one polyolefin, commercially available ethylene-acrylic ester copolymers and terpolymers include Elvaloy ™ manufactured by Du-Pont or Lotryl ™ manufactured by Arkema. In certain embodiments, each polymer layer in a polymer strip is made from the same polymer.

The polymeric layer may further comprise a friction-enhancing integral structure. This increased friction reduces the movement of the polymer strip with respect to the geotechnically strengthened material (GRM) it supports. Such friction-enhancing structures are generally formed by embossing. The structure may comprise a textured pattern, an embossed pattern, a hole, a finger-like extension, a hair-like extension, a wave-like extension, Patterns selected from the group consisting of co-extruded lines, dots, mats, and combinations thereof.

The polymer strip may have an overall thickness of about 0.1 mm to about 5 mm, an overall width of about 10 mm to about 5,000 mm and an overall length of about 10 mm to 5000 mm. In general, the average density of the hindered amine light stabilizer (HALS), the organic ultraviolet absorber and the inorganic ultraviolet absorbent in the outer polymer layer is the hindered amine light stabilizer (HALS) through the entire strip (ie, including the inner polymer layer). , About 1.2 to 10 times greater than the average density of organic and inorganic ultraviolet absorbers.

Next, some embodiments of the polymer strips used to make the cellular restriction system (CCS) of the present invention are described. The polymer strip can be a single layer or a multilayer strip. In certain embodiments, the polymer strip has at least one inner polymer layer and at least one outer polymer layer. The outer polymer layer is exposed to direct sunlight, while the inner polymer layer is not. In another particular embodiment, the polymer strip has two outer polymer layers. Each layer comprises ultraviolet, heat and humidity (UHH) resistant polymers, additives, fillers and / or barrier particles as described. Next, some specific embodiments are further described.

One embodiment is a single layer of ultraviolet, heat and humidity (UHH) resistant polymer strip. The polymer strip comprises a polymer, ultraviolet absorbent particles and hindered amine light stabilizer (HALS). The polymer may be a polyolefin or an ultraviolet, heat and humidity (UHH) resistant polymer and compounds thereof. The polymer strip may further comprise filler particles, pigments, dyes and / or barrier particles to ensure a polymer that is stable in ultraviolet, heat and humidity (UHH) conditions. The polymer strip was vivid colored. Even if the additive is added several times, the color of the polymer strip is preferentially determined by the pigment or dye used to make the color.

In another embodiment, the ultraviolet, heat and humidity (UHH) resistant polymer strip is a multi-layer strip, comprising 30 wt% (weight percent) to 85 wt% medium density polyethylene (MDPE) or high density polyethylene (HDPE); Up to 50 wt% linear low density polyethylene (LLDPE); Up to 20 wt% filler; And 0.005 wt% to 5 wt% of an additive selected from a UV absorber and a hindered amine light stabilizer (HALS). And 0.005 wt% to 5 wt% of barrier particles.

In another embodiment, the ultraviolet, heat and humidity (UHH) resistant polymer strip is a multi-layer strip, comprising from 30 wt% to 85 wt% medium density polyethylene (MDPE) or high density polyethylene (HDPE); Up to 50 wt% of ethylene-acrylic or methacrylic acid ester copolymers or terpolymers; Up to 20 wt% filler; And 0.005 wt% to 50 wt% of an additive selected from an ultraviolet absorber and a hindered amine light stabilizer (HALS). And 0.005 wt% to 5 wt% of barrier particles.

In another embodiment, the ultraviolet, heat and humidity (UHH) resistant polymer strip is a multilayer strip and has at least one layer comprising either polymer, filler and ultraviolet absorber or hindered amine light stabilizer (HALS). The layer may further comprise from 0.005 to 50% barrier particles. The layer provides an extrusion, evaporation and / or hydrolysis rate of at least 10% or less for the ultraviolet absorber, compared to a high density polyethylene (HDPE) layer having the same additive and the same size.

Methods for making the polymer layer (s) and / or strip (s) are provided. The method includes melt kneading at least one polymer with at least one additive in an extruder. The extruder may be a multi-screw extruder, in particular a twin-screw extruder. In another embodiment, the extruder is an idle twin screw extruder, in particular an idle twin screw extruder characterized by an L / D ratio of about 20-50. The extruder may be equipped with at least one side feeder, at least one atmospheric ventilation (for steam and air removal), and optionally a vacuum vent for removing gas from volatile monomers and gaseous compounds. This mixture is later pumped downstream to form films, strips, sheets, pellets, particulates, powders or extruded products.

A master batch may be made comprising a plurality of additives, where a master batch refers to a solution in which all or part of the additive is concentrated and / or dissolved in the polymer medium. The master batch of additive is fed from the hopper to the extruder and melt kneaded with the other components of the mixture. The melt is then pumped downstream in the extruder towards the dedicated mixing zone. The filler is then fed into the mixing zone from the top or side feeder. Capture air and absorbing moisture are removed by atmospheric ventilation. The mixture is further melt kneaded until most of the mass is crushed, and the filler is evenly dispersed in the mixture. Captured volatiles and / or by-products can be removed by selective vacuum ventilation. The result is then pumped through a die to form pellets or strips, or directly formed into the final polymer strip. Alternatively, the pellets can be formed after being melted again in a second extruder or molding machine.

In another step, a friction-enhancing monostructure is formed in the polymer layer (s) and / or strip (s). This structure can be formed by embossing, punching or extrusion. In particular, embossing is done by calendar embossing.

Prior art polymers are made in reactors. The reactor allows for the combination of several monomers in one skeleton. However, making the polymer in the reactor differs from making the polymer in the extruder. Reactors include ethylene-acrylic acid ester copolymers and terpolymers; Ethylene-methacrylic acid ester copolymers and terpolymers; It allows the preparation of ultraviolet resistant polymers such as acrylic ester copolymers and terpolymers. However, reactors do not make it possible to produce heat resistant polymers and UV, heat and humidity (UHH) resistant polymers as a product of finely dispersed, firmly mixed mixtures. The reactor does not allow dispersion of the nanoparticles or fillers. In particular, it is difficult to evenly distribute the filler in the reactor. However, it is easy to evenly disperse the filler, nanoparticles and one or more other polymers in the extruder. Extruder technology allows for nearly permanent combinations. Idle multi-screw extruders, and especially idle twin screw extruders, allow for microdispersion of particulates and other polymers. Without this strong mixing, the short and long term properties of the polymers produced are inferior.

Three-dimensional cellular confinement systems are formed of a plurality of ultraviolet, heat and humidity (UHH) resistant polymer strips. In general, each strip has a wave-shaped pattern with mountains and valleys. The acid of one strip is connected to the valleys of the other strip to form a honeycomb-like pattern. In other words, the strips are stacked parallel to one another and internally connected by a plurality of separate physical joints, which are spaced apart from each other by unjoined portions. The joint may be formed by welding, bonding, sewing or any combination thereof. In a specific embodiment, the joint is welded by ultrasonic means. In another embodiment, the joint is welded by unpressurized ultrasonic means. In an embodiment, the distance between adjacent joints is from about 50 mm to about 1200 mm. The first polymer strip of the plurality of polymer strips is stacked parallel to the second polymer strip of the plurality of polymer strips and connected to the second polymer strip by a plurality of separate physical joints, the joints being connected to the non-connected portion of the polymer strip. Can be spaced apart from each other. The first polymer strip may have a coefficient of thermal expansion of up to 150 ppm / ° C.

The polymer strip herein has a number of desirable features. By mixing the fillers, not only improved weld quality but also improved thermal conductivity to avoid temperature increases. The filler also lowers the CTE, resulting in improved dimensional stability. By mixing the barrier particles, leaching and / or evaporation of additives and the ingress of moisture, protons or hydroxyl ions into the polymer strip are reduced. By using the ultraviolet absorbing particles, a holding force with improved ultraviolet resistance is obtained for a period of about 100 years.

The cellular limiting system (CCS) of this disclosure has improved weld strength and durability. The weld strength is at least 10% better than assuming that the additives are equal in a polymer strip composed of pure high density polyethylene (HDPE). When the welded strip is loaded for a long time, its failure rate is at least 10% lower than when the welded strip composed of pure high density polyethylene (HDPE) had an equivalent amount of additives. In addition, the welding cycle is at least 10% faster when there is an equivalent amount of additive in the polymer strip composed of pure high density polyethylene (HDPE). This improved welding performance is particularly significant when ultrasonic welding is used because polyethylene is relatively difficult due to its low density, crystallinity and low coefficient of friction.

It is important to protect the welding from the poor welding condition. The welds are relatively weak in the cellular limiting system (CCS), and if one weld fails, the load is transferred to the other weld, which increases the load, increasing the likelihood of failing too. Providing a weld with increased weld strength prevents this happening.

The cellular restriction system (CCS) herein also has a low rate of extrusion, evaporation or hydrolysis. When the extrusion is performed in water at ambient temperature for a period from about 6 months to about 24 months, at least 10% lower hindered amine light stabilizer (HALS) and / or organic compared to high density polyethylene (HDPE) strips of the same thickness. The same average concentration of the hindered amine light stabilizer (HALS) and the ultraviolet absorber throughout the high density polyethylene (HDPE) strip (compared to the layers of the cellular restriction system (CCS) herein) with an extrusion ratio to the ultraviolet absorber. Has The residue content of the polymer can be determined by gas chromatography (GC), high performance liquid chromatography (HPLC) or similar methods.

It also has the same thickness and elasticity (extended to break) compared to high density polyethylene (HDPE) strips having the same average concentration of hindered amine light stabilizers (HALS) and / or organic ultraviolet absorbers across the high density polyethylene (HDPE) strips. When measured and measured by Delta E color, the cellular restriction system (CCS) has at least 10% lower resolution.

This specification will be further described in the following non-limiting examples, which are illustrative only and it is understood that this specification is not limited to the materials, states, process parameters, and the like listed herein. Can be. All percentages are by weight unless otherwise indicated.

Example

Example 1

Five ultraviolet, heat and humidity (UHH) resistant mixtures (INV1 to INV5) and reference mixtures are made. The composition is shown in Table 1. In addition, each mixture contains 0.5 wt% TiO ₂ pigment (Kronos ^™ 2222 manufactured by Kronos) and 0.2 wt% PV Fast Brown HFR ^™ brown pigment (made by Clarit). The polymers, additives and pigments are fed to the main hopper of an idle twin screw extruder running at 100 to 400 RPM at a barrel temperature of 180 to 240 degrees Celsius. The polymer is dissolved and the additive is dispersed by at least one dough zone. The filler is provided from the side feeder. Steam and gas are removed by atmospheric ventilation, and the product is made into pellets by a strand pelletizer.

HDPE resin-HDPE M 5010 manufactured by Dow

LLDPE resin-LL 3201 manufactured by Exxon Mobil

Ethylene-Acrylic Resin-Lotryl ^TM 29MA03 manufactured by Arkema

Talc-Iotalk ^TM Fine Powder from Yokal

Organic UV Absorbers-Tinuvin ^TM 234 manufactured by Ciba

Inorganic Ultraviolet Absorbers-SACHTLEBEN ^TM Hombitec RM 130F TN manufactured by Sachtleben

HALS-Chimassorb ^TM 944 manufactured by Ciba

Nano-clay-Nanomer ^TM I31PS made from Nanocor

Next, five polymer strips ST1 to ST5 and one reference strip are made. All strips are manufactured in a sheet extrusion line comprising a main single screw extruder for the center layer and two auxiliary single screws for the outer layer. The thickness of the center layer is 0.8 mm and the outer layers each have a thickness of 0.20 mm. The composition of the strips is shown in Table 2. The name of the polymer in each layer follows from Table 1.

HDPE Resin-HDPE M 5010 manufactured by Dow. No UV absorber or hindered amine light stabilizer (HALS) additive.

evaluation

The strips were evaluated for UV, heat and humidity (UHH) resistance by accelerated aging in Heraeous Xenotest 1200W WOM, relative humidity = 60%, black panel = 60 ° C., 120 minutes dry cycle, 18 minutes moisture cycle. The color difference (delta E) and the relative loss of elongation to break ((first extension length-final extension length) divided by the initial extension length) were measured after 10,000 hours of aging. The results are summarized in Table 3.

Example 2

Five mixtures (INV6 to INV10) and reference mixtures are made. The composition is shown in Table 4. In addition, each mixture contains 0.5 wt% TiO ₂ pigment (Kronos ^™ 2222 manufactured by Kronos) and 0.2 wt% PV Fast Brown HFR ^™ brown pigment (made by Clariant). The polymers, additives and pigments are fed to the main hopper of an idle twin screw extruder running at 100 to 400 RPM at a barrel temperature of 260 to 285 degrees Celsius. The polymer is dissolved and the additive is dispersed by at least one dough zone. The filler is provided from the side feeder. Steam and gas are removed by atmospheric ventilation and the product is pelletized by strand pelletizers.

MA Functional HDPE Resin—HDPE M 5010 prepared in Dow and fused with 0.25-0.40% maleic anhydride (MA) in a reactive extruder.

Pure HDPE-HDPE M 5010 manufactured by Dow. MA Not functionalized.

Ethylene-Acrylic Resin-Lotryl ^™ 29MA03 manufactured by Arkema.

Talc-Iotalk ^™ fine powder manufactured by Yokal.

Organic Ultraviolet Absorbers-Tinuvin ^TM 234 manufactured by Ciba.

Inorganic Ultraviolet Absorbers-SACHTLEBEN ^™ Hombitec RM 130F TN manufactured by Sachtleben.

HALS-Chimassorb ^™ 944 manufactured by Ciba.

Nano-Clay-Nanomer ^™ I31PS manufactured by Nanocor.

Next, five polymer strips ST6 to ST10 and one reference strip are made. All strips are manufactured in a sheet extrusion line that includes a main single screw extruder for the center layer and two auxiliary single screws for the outer layer. The thickness of the center layer is 0.8 mm and the outer layers each have a thickness of 0.20 mm. The core layer is made of HDPE M 5010 manufactured by Dow, and the outer layer is made of the composition according to Table 4. The composition is similar to that shown in Table 2, in which RefB has two outer layers of composition reference 2 and ST6 has two outer layers of composition INV6.

evaluation

The strips were evaluated for UV, heat and humidity (UHH) resistance in the high temperature region. The strips were heated in an oven at 110 ° C. for 7 days and then the relative loss of elongation to break was measured. This simulates the loss of additives by evaporation.

Next, to determine the UV, heat and humidity (UHH) resistance, the strips were subjected to moisture and heat by aging in water at 85 ° C. for 7 days to allow extrusion and hydrolysis of the additive. The strips were then exposed to artificial sunlight with Heraeus Xenotest 1200 W WOM with relative humidity = 60%, black panel = 60 ° C., 120 minutes of dry cycles, 18 minutes of moisture cycles. The relative loss of color difference (delta E) and elongation to break was measured after 10,000 hours of aging. The results are summarized in Table 5.

Next, 20 strips of each composition of 100 mm length were welded by an ultrasonic horn of 20 MHz to obtain 10 pairs. Five pairs of each composition were chosen randomly and their tensile strength was measured 48 hours after welding (T = 0). The 5 pairs were then subjected to aging in an oven at 110 ° C. for 21 days and then the tensile strength was measured again (T = 21d). The measured mean values are given in Table 6.

Although particular embodiments have been described, alternatives, modifications, changes, improvements, and substantially equivalents that are not currently foreseen, can be envisioned by the applicant or those skilled in the art. Accordingly, the appended claims which can be submitted and amended are meant to include all such alternatives, modifications, changes, improvements and substantially equivalents.

This disclosure is generally available for polymeric cellular confinement systems that may be filled with soil, concrete, aggregates, geological material, and the like. In particular, the present invention is applicable to cellular restriction systems characterized by improved robustness against damage caused by ultraviolet light, humidity, invasive soils, and combinations thereof.

Claims (39)

A robust cellular confinement system consisting of a plurality of polymer strips; Each polymer strip has at least one outer polymer layer and at least one inner polymer layer, At least one outer polymer layer comprises (a) (iii) high density polyethylene (HDPE) or (ii) medium density polyethylene (MDPE); And (b) (i) an ultraviolet absorber or (ii) a hindered amine light stabilizer (HALS), wherein at least one outer polymer layer has a greater concentration of additives than at least one inner polymer layer. Cellular restriction system. The method of claim 1, Wherein each polymer strip comprises a first and a second outer polymer layer, wherein all of the inner polymer layer lies between the first outer polymer layer and the second polymer layer. The method of claim 1, Wherein said at least one inner polymer layer comprises an additive in an amount of less than 0.5 wt% (weight percent) by weight. The method of claim 1, The at least one outer polymer layer of each polymer strip further comprises an additive selected from the group consisting of antioxidants, pigments, dyes, carbon blacks and barrier particles. 5. The method of claim 4, Antioxidant is selected from the group consisting of hindered phenols, phosphites, phosphates and aromatic amines. 5. The method of claim 4, Pigment or dye is a cellular restriction system, characterized in that the polymer strip is not black or dark gray. 5. The method of claim 4, And said barrier particle is selected from the group consisting of clays, organo-modified clays, nanotubes, metal flakes, ceramic flakes, metal coated ceramic flakes and glass flakes. The method of claim 1, At least one outer polymer layer comprises an ultraviolet absorber which is an inorganic particle comprising a material selected from the group consisting of titanium salts, titanium oxides, zinc oxides, zinc halides and zinc salts. The method of claim 8, The inorganic ultraviolet absorber particles are nanoparticles having an average diameter of 5 to 100 nanometers. The method of claim 1, Wherein said at least one layer further comprises a filler. The method of claim 10, The filler is in the form of whiskers or fibers and has a mean particle size of less than 50 micrometers. The method of claim 10, The fillers include mineral fillers, metal oxides, metal carbonates, metal sulfates, metal phosphates, metal silicates, metal borates, metal hydroxides, silicas, silicates, aluminates, aluminosilicates, fibers, whiskers, industrial materials ( ash, concrete powder or cement, natural fiber, kenaf, hemp, flax, ramie, sisal, newsprint fiber, paper mill sludge, sawdust, wood flour, Cellular restriction system, characterized in that it is selected from the group consisting of carbon, aramid and mixtures thereof. The method of claim 10, And said filler is a mineral selected from the group consisting of calcium carbonate, barium sulfate, dolomite, alumina trihydrate, talc, bentonite, kaolin, ulastonite, clay and mixtures thereof. The method of claim 10, The surface of the filler is a sizing agent selected from the group consisting of fatty acids, esters, amides and salts thereof, silicone containing polymers or oligomers, organometallic compounds, titanates, silanes and zirconates. Or treated with a binder. The method of claim 10, The filler has a high thermal conductivity and is selected from the group consisting of metal carbonates, metal sulfates, metal oxides, metals, metal coated minerals and oxides, aluminosilicates and mineral fillers. The method of claim 1, Wherein said at least one outer polymer layer comprises an ultraviolet absorber that is benzotriazole or benzophenone. The method of claim 1, Wherein said ultraviolet absorber or hindered amine light stabilizer (HALS) is present at 0.01 to 2.5 wt% based on the weight of at least one outer polymer layer. The method of claim 1, Wherein said at least one inner polymer layer further comprises from 0 to 0.25 wt% of a UV absorber and a hindered amine light stabilizer (HALS) based on the weight of the at least one inner polymer layer. The method of claim 1, At least one polymer layer of each polymer strip comprises high density polyethylene (HDPE), medium density polyethylene (MDPE), ethylene-acrylic acid ester copolymers and terpolymers, ethylene-methacrylic acid ester copolymers and terpolymers, acrylic acid ester copolymers. And a polymer selected from the group consisting of terpolymers, fatty polyesters, fatty polyamides, fatty polyurethanes, mixtures thereof, and mixtures thereof with at least one polyolefin. The method of claim 1, At least one polymer layer of each polymer strip comprises a fibrous pattern, an embossed pattern, a hole, a finger-like extension, a hairy extension, a wave-like extension, a coextrusion line, a dot, a mat, and these And a friction-enhancing structure selected from the group consisting of: The method of claim 1, Each polymer strip has a total thickness of 0.1 mm to 5 mm, a total width of 10 mm to 500 mm, and a total length of 10 mm to 5,000 mm. The method of claim 1, Each polymer strip consists of a first and a second outer polymer layer, wherein one outer polymer layer has a higher UV absorber and hindered amine light stabilizer (HALS) additive concentration than the other outer polymer layer. Limiting system. The method of claim 1, At least one layer of each polymer strip may comprise 30 wt% to 85% medium density polyethylene (MDPE) or high density polyethylene (HDPE); Up to 50 wt% linear low density polyethylene (LLDPE); Up to 20 wt% mineral fillers; 0.005 wt% to 5 wt% of an additive selected from the group consisting of UV absorbers and hindered amine light stabilizers (HALS); And 0.005 wt% to 5 wt% barrier particles. The method of claim 1, At least one layer of each polymer strip may comprise 30 wt% to 85% medium density polyethylene (MDPE) or high density polyethylene (HDPE); Up to 50 wt% ethylene-acrylic acid ester copolymer or terpolymer; Up to 20 wt% mineral fillers; 0.005 to 5 wt% of an additive selected from the group consisting of a ultraviolet absorber and a hindered amine light stabilizer (HALS); And 0.005 wt% to 5 wt% barrier particles. The method of claim 1, At least one outer polymer layer includes ethylene-acrylic acid ester copolymers and terpolymers, ethylene-methacrylic acid ester copolymers and terpolymers, acrylic acid ester copolymers and terpolymers, fatty polyesters, fatty polyamides, fatty polyurethanes, these And a ultraviolet absorber and a polymer selected from the group consisting of a mixture thereof, and a mixture thereof having at least one polyolefin; The first polymer strip of the plurality of polymer strips is stacked parallel to the second polymer strip of the plurality of polymer strips and connected to the second polymer strip by a plurality of separate physical joints, the joints being connected to the non-connected portion of the polymer strip. Cellular restriction system, characterized in that spaced apart from each other. The method of claim 25, Wherein the joints are formed by welding, bonding, stitching, or a combination thereof. The method of claim 25, And the joints are formed by ultrasonic means. The method of claim 25, Cellular confinement system, characterized in that the spacing between adjacent joints is 50mm to 1,200mm. The method of claim 25, And wherein the weld strength of the joint is at least 10% greater than the weld strength of the joint made from a polymer strip consisting of pure high density polyethylene (HDPE) and an equivalent amount of ultraviolet absorbent loaded. The method of claim 25, The failure rate of the joint is at least 10% less than the failure rate of a joint made from a polymer strip consisting of pure high density polyethylene (HDPE) and a loaded amount of ultraviolet absorbent. The method of claim 25, Cellular restriction system, characterized in that the first polymer strip has a coefficient of thermal expansion of 150 ppm / ° C. or less. The method of claim 1, At least one outer polymer layer comprises (a) an ethylene-acrylate polymer and (iii) a high density polyethylene (HDPE) or (ii) a medium density polyethylene (MDPE); And (b) a polymer mixture of (i) a UV absorber or (ii) a hindered amine light stabilizer (HALS). 33. The method of claim 32, The ethylene-acrylate polymers include ethylene-acrylic acid ester copolymers and terpolymers; And an ethylene-methacrylic acid ester copolymer and a terpolymer. delete delete delete delete delete delete

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