CN111559131A

CN111559131A - Elastomer modified pre-crosslinked polyethylene composite film layer and preparation method and application thereof

Info

Publication number: CN111559131A
Application number: CN202010240585.XA
Authority: CN
Inventors: 靳庆新
Original assignee: Weft Solid Anticorrosion Resources Shanghai Co ltd
Current assignee: Weft Solid Anticorrosion Resources Shanghai Co ltd
Priority date: 2020-03-31
Filing date: 2020-03-31
Publication date: 2020-08-21

Abstract

The invention discloses an elastomer modified pre-crosslinked polyethylene composite film layer, a preparation method thereof and application thereof in an automatic leakage detection elastomer modified pre-crosslinked polyethylene anticorrosion structure. The elastomer modified pre-crosslinked polyethylene composite film layer comprises an elastic PE film layer and a fiber felt which are sequentially compounded; the elastic PE film layer is made of a polyethylene resin composition containing polyethylene resin. The preparation method comprises the following steps: and compounding the elastic PE film layer obtained by extruding and molding the polyethylene resin composition by a T-shaped die through an extruding machine with a fiber felt, and pressing the composite film layer by a pressing roller of the extruding machine to obtain the elastomer modified pre-crosslinked polyethylene composite film layer. The anti-corrosion structure layer has better anti-corrosion capability, better anti-thermal expansion and cold and mechanical impact resistance.

Description

Elastomer modified pre-crosslinked polyethylene composite film layer and preparation method and application thereof

Technical Field

The invention relates to an elastomer modified pre-crosslinked polyethylene composite film layer, a preparation method and application thereof, in particular to an automatic leakage detection elastomer modified polyethylene anticorrosion and waterproof structure, and belongs to the technical field of building anticorrosion and waterproof systems.

Background

In chemical industry, petroleum industry, metallurgy industry, papermaking industry, pharmacy, environmental protection industry and the like, a large amount of chemical substances have corrosivity of different degrees, and the corrosion can cause damage to equipment and building structures and pollution to the environment. The cost of corrosion prevention in various industries is very high every year, and the common corrosion prevention forms of concrete chemical pools, ditches, ground surfaces and the like and storage tanks and equipment of steel structures are thermosetting resin glass fiber reinforced plastics, various coatings and the like. For the corrosion prevention of the coating, the coating is easy to crack and delaminate due to overlarge rigidity and large difference between the thermal expansion coefficient and the matrix, and the coating is easy to have uneven thickness and generate pinholes during construction, has poor permeability resistance and limited corrosion prevention capability, is usually only suitable for light corrosion prevention working conditions and has short service life; the thermosetting resin glass fiber reinforced plastic has good corrosion resistance, but is easy to separate from a matrix and crack due to the reasons of high rigidity, curing shrinkage, difference of thermal expansion coefficient with the matrix and the like, needs to be maintained frequently, and has a service life of only a few years. For a plurality of concrete ditches and tanks and various tanks, after the anticorrosive coating is damaged, not only is the economic cost caused, but also the underground water is polluted due to the leakage of a plurality of chemical media.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the building matrix is easy to be corroded and damaged, and causes pollution to underground water and ground.

Aiming at the technical problems in the prior art, the invention provides an elastomer modified pre-crosslinked polyethylene composite film layer which is characterized by comprising an elastic PE film layer and a fiber felt which are sequentially compounded; the elastic PE film layer is made of a polyethylene resin composition containing polyethylene resin.

Preferably, the polyethylene resin composition is an ethylene homopolymer and an alpha-olefin-ethylene copolymer having 4 to 20 carbon atoms.

More preferably, the raw materials of the polyethylene resin composition comprise the following components in percentage by mass:

60 to 95% of a polyethylene resin, preferably having a melt mass flow rate (MFR, ASTM D1238) of 0.5 to 10g/10 min (230 ℃/2.16 kg);

2 to 39.7% of thermoplastic elastomer resin, preferably 1 to 20g/10 min (230 ℃/2.16kg) of melt mass flow rate (MFR, ASTM D1238);

0.1-5% of cross-linking agent for improving tensile strength of the film layer;

0-1.5% of peroxide;

0.1 to 5 percent of plasticizer for improving the fluidity of the resin;

0.1-4% of ultraviolet protective agent for improving functionality;

0 to 5 percent of pigment.

Further, the crosslinking agent is any one or combination of several of a peroxide crosslinking agent, a silane crosslinking agent and an azo crosslinking agent.

Preferably, the thickness of the elastic PE film layer is 0.5-5 mm. The thickness of the elastomer modified pre-crosslinked polyethylene composite film layer is preferably 1-3 mm.

Preferably, the part of 5-100 mm of one side edge of the elastomer modified pre-crosslinked polyethylene composite film layer only comprises an elastic PE film layer and does not comprise a fiber felt, so that the later welding construction is facilitated.

Preferably, the fiber felt is a carbon fiber felt which is composed of carbon fiber heating wires, and PE film layer wires are uniformly distributed in the carbon fiber felt. The fiber felt has a conductive function.

Preferably, the fiber felt is polyester felt, polyester felt or glass fiber felt. The fiber mat does not have a conductive function.

The invention also provides a preparation method of the elastomer modified pre-crosslinked polyethylene composite film layer, which is characterized in that an elastic PE film layer obtained by extrusion molding of the polyethylene resin composition by a T-shaped die through an extruding machine is compounded with a fiber felt and is pressed by the extruding machine to obtain the elastomer modified pre-crosslinked polyethylene composite film layer.

Preferably, the extrusion temperature of the extruder is not more than (melting point of the polyethylene resin +35 ℃), and the residence time of the polyethylene resin composition in the extruder is controlled to be 2 to 10 min. By controlling the temperature and the time in the mode, the insufficient crosslinking is realized, partial pre-crosslinking monomers are contained in the structure, and when the hot-melt welding is adopted, the high-temperature induced pre-crosslinking monomers are further crosslinked on the welding surface, so that the toughness is better, a more firm welding interface is bonded, and the firmness and the reliability of the post-hot welding are improved.

Preferably, when the fiber felt is a carbon fiber felt, the fiber felt is subjected to pre-immersion liquid pre-immersion treatment before compounding; the pre-immersion liquid is polyvinyl alcohol, polyvinyl acetate or acrylic acid.

The invention also provides an automatic leakage detection elastomer modified pre-crosslinked polyethylene anticorrosion structure which is characterized by comprising a PE base layer membrane system, wherein the PE base layer membrane system adopts the elastomer modified pre-crosslinked polyethylene composite membrane layer of claim 7, one side of a carbon fiber felt of the elastomer modified pre-crosslinked polyethylene composite membrane layer is fixed on the inner wall of a base body through a bonding agent, a PE membrane layer lead in the elastomer modified pre-crosslinked polyethylene composite membrane layer is connected with a current exchanger, and the current exchanger is sequentially connected with a power supply, an alarm, a liquid connecting line and a liquid induction device; when in use, the liquid sensing device is arranged in the substrate.

Preferably, the recesses on the inner wall of the base body are filled with a repair material.

More preferably, the repair material is at least one of mortar and putty.

Preferably, the binder is epoxy clay or polyurethane asphalt clay, preferably polyurethane asphalt clay with excellent corrosion resistance and other clay with certain toughness after elastomer modification.

Preferably, the inner wall of the substrate is coated with a primer; the primer is epoxy primer or polyurethane primer.

Preferably, all the PE film layer wires are connected in parallel and then connected with the current exchanger, so that when any part of the anticorrosive lining is damaged, the carbon fiber layer and the liquid connecting line are communicated by the permeated liquid, and after the resistance is greatly reduced, the current is enhanced so as to induce an alarm to give an alarm; or each PE film layer wire is connected with a current exchanger, each current exchanger is connected with an alarm or all the current exchangers are connected in parallel and then connected with an alarm. When the latter connection mode is adopted, the system not only has the function of alarming immediately after leakage, but also has the function of confirming a specific leakage position through a switching circuit.

Preferably, the PE base layer membrane system is an elastomer modified pre-crosslinked polyethylene composite membrane layer of an integral structure or a splicing structure formed by splicing a plurality of elastomer modified pre-crosslinked polyethylene composite membrane layers, when the splicing structure is adopted, the edges of adjacent elastomer modified pre-crosslinked polyethylene composite membrane layers are overlapped, and the width d of the overlapped part is 5-100 mm.

More preferably, the elastomer-modified pre-crosslinked polyethylene composite film layer on the side close to the substrate in the overlapping portion includes only the elastic PE film layer.

More preferably, after the elastomer modified pre-crosslinked polyethylene composite film layer is fixed on the base body through the adhesive, the overlapped part is subjected to hot-melt welding through a hot-melt welding machine, and then the splicing part of the adjacent elastomer modified pre-crosslinked polyethylene composite film layer is subjected to repair welding through a hot-melt welding strip as required to completely seal the splicing seam.

Further, the specific process of the hot melting welding is as follows: and preheating the overlapped part for 5-120 s, and then carrying out hot-melt welding at the temperature of between the melting point of the polyethylene resin and (the melting point of the polyethylene resin and 55 ℃) and at the temperature of not less than 480 ℃.

The invention provides a safe and reliable anti-corrosion structure, which has excellent anti-corrosion performance, can resist the corrosion of most of acid, alkali, salt and other chemical media, has uniform thickness, high toughness and excellent bonding performance, can never delaminate due to temperature expansion, has good weldability, and is connected at the joint part by adopting a hot welding mode to form a continuous and integral anti-corrosion structure. The invention can well solve the problems of the prior common anticorrosive coating or glass fiber reinforced plastic lining, and greatly reduce the maintenance cost and the environmental pollution risk. The traditional hot-melt welding needs repair welding outside a welding seam to ensure the welding quality, and the invention can realize one-time hot-melt welding to obtain high welding quality, thereby saving labor and time.

The anti-corrosion structure layer has better anti-corrosion capability, better anti-thermal expansion and cold and mechanical impact resistance. Because the modified polyethylene anticorrosion structure is subjected to insufficient crosslinking through temperature and time control in the crosslinking process, the structure contains partial pre-crosslinking monomers, when hot-melt welding is adopted, the pre-crosslinking monomers are further crosslinked on a welding surface under the induction of high temperature, a welding interface with better toughness and firmer bonding is formed, and the firmness and the reliability of the post-hot welding are improved. The technology solves the problem of unstable welding surface of the thermoplastic sheet, in addition, the invention also solves the leakage monitoring problem through the pre-compounded conducting layer, is a safe, reliable, long-acting and controllable anti-corrosion solution, greatly reduces the maintenance and reconstruction cost of the anti-corrosion lining of a user unit, and avoids the problem of unexpected shutdown and production halt caused by corrosion.

Compared with the prior art, the invention has the beneficial effects that:

1) the PE film layer made of the PE material composition of the main formula by adopting the extrusion molding process has excellent impact resistance, is soft, has extremely high elongation, has good corrosion resistance, excellent reheating welding performance, excellent adhesiveness and easy construction.

2) Through the optimization of the whole structure, the PE composition in the automatic leakage-detecting elastic modified polyethylene anticorrosion structure is extruded by adopting a plate or a sheet, and then enters a compression roller together with a non-woven fabric or a carbon fiber felt (cloth) subjected to surface pretreatment, so that the interfaces of the non-woven fabric or the carbon fiber felt (cloth) are fused and bonded, and the composite non-woven fabric or the carbon fiber felt (cloth) has good adhesion and a conductive monitoring function.

3) When the PE material composition is manufactured by adopting an extrusion molding process, the temperature and time are controlled, and the resin is not fully crosslinked, so that the structure comprises partial pre-crosslinking monomers, when hot-melt welding is adopted, the pre-crosslinking monomers are induced by high temperature to be further crosslinked on a welding surface, a welding interface with better toughness and firmer bonding is formed, and the firmness and the reliability of the post-hot welding are improved.

Drawings

FIG. 1 is a schematic view of an automatic leak detection elastomer modified polyethylene corrosion protection structure provided by the present invention;

FIG. 2 is an enlarged view of a portion I of FIG. 1;

FIG. 3 is a cross-sectional view taken along the line A-A in FIG. 1;

FIG. 4 is an enlarged view of a portion II of FIG. 3;

FIG. 5 is a schematic view of the connection of the elastomer-modified pre-crosslinked polyethylene composite film layer with other components;

fig. 6 is a cross-sectional view taken along the plane B-B in fig. 5.

Detailed Description

In order to make the invention more comprehensible, preferred embodiments are described in detail below with reference to the accompanying drawings.

Examples

As shown in fig. 1-6, the automatic leakage detection elastomer modified polyethylene anticorrosion structure provided by the invention comprises a PE base layer film system 30, wherein the PE base layer film system 30 adopts an elastomer modified pre-crosslinked polyethylene composite film layer, one side of a carbon fiber felt 31 of the elastomer modified pre-crosslinked polyethylene composite film layer is fixed on the inner wall of a substrate 10 through an adhesive 20, a PE film layer lead 38 in the elastomer modified pre-crosslinked polyethylene composite film layer is connected with a current exchanger 37, and the current exchanger 37 is sequentially connected with a power supply 36, an alarm 35, a liquid connecting line 34 and a liquid sensing device 39; in use, the liquid sensing device 39 is located within the substrate 10.

The elastomer modified pre-crosslinked polyethylene composite film layer comprises an elastic PE film layer 32 and a carbon fiber felt 31 which are sequentially compounded, wherein the carbon fiber felt 31 is composed of carbon fiber heating wires 33, and PE film layer leads 38 are uniformly distributed in the carbon fiber felt 31; the material of the elastic PE film layer 32 is a polyethylene resin composition containing polyethylene resin. The thickness of the elastic PE film layer 32 is 2 mm. The thickness of the elastomer modified pre-crosslinked polyethylene composite film layer is 3 mm. The polyethylene resin composition comprises the following raw materials in percentage by mass:

80% of a linear low density polyethylene resin having a melt mass flow rate (MFR, ASTM D1238) of 1.5g/10 min (230 ℃/2.16 kg);

13% of a polyolefin thermoplastic elastomer resin having a melt mass flow rate (MFR, ASTM D1238) of 1g/10 min (230 ℃/2.16 kg);

2% of a silane cross-linking agent;

0.5 percent of peroxide;

2% of plasticizer;

0.5 percent of ultraviolet protective agent;

2% of pigment (PE primary color master batch);

carbon fiber felt gram weight 500g/m²。

The elastomer modified pre-crosslinked polyethylene composite film layer only comprises the elastic PE film layer 32 at the 100mm part of one side edge, and does not comprise the fiber felt.

The preparation method of the elastomer modified pre-crosslinked polyethylene composite film layer comprises the following steps:

the elastic PE film layer 32 obtained after the polyethylene resin composition is extruded and molded by an extruding machine through a T-shaped die head is compounded with the carbon fiber felt 31 (the carbon fiber felt 31 is subjected to pre-dipping liquid pre-dipping treatment before being compounded, wherein the pre-dipping liquid is polyvinyl alcohol) and is pressed by the extruding machine to obtain the elastomer modified pre-crosslinked polyethylene composite film layer. The temperature of the plasticizing zone of the extruder was 160 ℃ and the residence time of the polyethylene resin composition in the extruder was controlled to 5 min.

The binder 20 adopts flexible polyurethane asphalt cement, pastes PE base layer membrane system 30 at

base member

10, and 11 surfaces of former base member need carry out the sandblast or polish the processing to guarantee clean dry, can adopt repair material 12 to repair to the base member shrinkage pool is dark and level, repair material 12 is mortar and putty. The mortar products comprise a weft-bonded cement-based layer fiber reinforced repair mortar Winprof BFRM, a special repair mortar MO-60 for a DH-type chimney in Delhao chemical industry, Audtimem RM702 mortar and RM770 mortar, and the adhesive comprises a weft-bonded Winff additive/Membrane and a Winff additive/Membrane-E. The inner wall of the substrate 10 is coated with primer; the Primer is epoxy Primer or polyurethane Primer, and the epoxy Primer products comprise WinfEX Primer WinfF CS Primer, JOTUN Penguard Clear Sealer pure epoxy sealing varnish, ARDEX Asias R3E epoxy moisture-resistant Primer, and Hancheng chemical MIL-2001-APU.

The PE-based film system 30 is an elastomer-modified pre-crosslinked polyethylene composite film layer of an integral structure or a spliced structure formed by splicing a plurality of elastomer-modified pre-crosslinked polyethylene composite film layers. When an integral structure is adopted, the integral structure can be customized according to the size of the required part, and the large-area splicing phenomenon is reduced. When the splicing structure is adopted, PE base layer films with different shapes and sizes are produced, and splicing and thermal welding are carried out to form a whole in the construction process. This PE rete is owing to compound surface treatment's non-woven fabrics, has the very good adhesion nature with the adhesive, the non-woven fabrics can adopt polyester, polypropylene, structural layer such as glass fiber, when adopting carbon fiber felt 31 as the tie coat, place carbon fiber heating wire 33 in carbon fiber felt 31, and be connected in wire group and leak hunting system, the tie coat just possesses even electrically conductive function, can regard as the electrically conductive route of seepage, and realize on-line monitoring in wire group and leak hunting system access, the accessible electrorheological change, temperature variation sets up alarm system.

When a splicing structure is adopted, the edges of the adjacent elastomer modified pre-crosslinked polyethylene composite film layers are overlapped, and the width d of the overlapped part is 100 mm. The elastomer-modified pre-crosslinked polyethylene composite film layer on the side of the substrate 10 in the overlap portion includes only the elastic PE film layer 32.

After the elastomer modified pre-crosslinked polyethylene composite film layer is fixed on the base body 10 through the adhesive 20, the overlapped part is subjected to hot-melt welding by a hot-melt welding machine, and then the splicing part of the adjacent elastomer modified pre-crosslinked polyethylene composite film layer is subjected to repair welding by a hot-melt welding strip as required to completely seal the splicing seam. The specific process of the hot melting welding is as follows: preheating the overlapped part for 60s, and then performing hot-melt welding at the preheating temperature of 180 ℃ and the hot-melt welding temperature of 500 ℃.

When a leakage detection system is used, the connection mode of the lead group comprises two modes:

the first connection mode is as follows: all PE film layer wires 38 are connected in parallel and then connected to a current exchanger 37. At the moment, after any part of the anticorrosion lining is damaged, the permeated liquid can communicate the carbon fiber felt 31 with the liquid connecting line 34 led out from the liquid in the anticorrosion groove (pool), and after the resistance is greatly reduced, the current is enhanced to induce the alarm 35 to give an alarm.

The second connection mode is as follows: each PE film wire 38 is connected to a current exchanger 37, and each current exchanger 37 is connected to an alarm 35 or all current exchangers 37 are connected in parallel and then connected to an alarm 35. When the second connection mode is adopted, the system not only has the function of alarming immediately after leakage, but also has the function of confirming a specific leakage position through a switching circuit.

When an alarm system is not used, the PE-based film system 30 can be used as a replacement for a conventional corrosion resistant coating or a glass fiber reinforced plastic lining.

Claims

1. An elastomer modified pre-crosslinked polyethylene composite film layer is characterized by comprising an elastic PE film layer (32) and a fiber felt which are sequentially compounded; the elastic PE film layer (32) is made of a polyethylene resin composition containing polyethylene resin.

2. The elastomer-modified pre-crosslinked polyethylene composite film layer according to claim 1, wherein the polyethylene resin composition is an ethylene homopolymer and an α -olefin-ethylene copolymer having 4 to 20 carbon atoms.

3. The elastomer-modified pre-crosslinked polyethylene composite film layer according to claim 2, wherein the raw materials of the polyethylene resin composition comprise the following components in mass percent:

60% -95% of polyethylene resin;

2 to 39.7 percent of thermoplastic elastomer resin;

0.1 to 5 percent of cross-linking agent;

0-1.5% of peroxide;

0.1 to 5 percent of plasticizer;

0.1 to 4 percent of ultraviolet protective agent;

0 to 5 percent of pigment.

4. The elastomer-modified pre-crosslinked polyethylene composite film layer of claim 3, wherein the crosslinking agent is any one or a combination of peroxide crosslinking agent, silane crosslinking agent and azo crosslinking agent.

5. The elastomer-modified pre-crosslinked polyethylene composite film layer according to claim 1, wherein the thickness of the elastic PE film layer (32) is 0.5 to 5 mm; the elastomer modified pre-crosslinked polyethylene composite film layer only comprises an elastic PE film layer (32) at the part of 5-100 mm of one side edge, and does not comprise a fiber felt.

6. The elastomer-modified pre-crosslinked polyethylene composite film according to any one of claims 1 to 5, wherein the fiber felt is a carbon fiber felt (31), the carbon fiber felt (31) is composed of carbon fiber heating wires (33), and PE film layer conducting wires (38) are uniformly distributed in the carbon fiber felt (31); or the fiber felt is polyester felt, polyester felt or glass fiber felt.

7. The process for preparing an elastomer-modified pre-crosslinked polyethylene composite film according to any one of claims 1 to 6, wherein the elastomer-modified pre-crosslinked polyethylene composite film is obtained by compounding an elastic PE film layer (32) obtained by extrusion molding of the polyethylene resin composition by a T-die using an extruder with a fiber mat and passing the compounded layer through rolls of the extruder.

8. The method of preparing an elastomer-modified pre-crosslinked polyethylene composite film according to claim 7, wherein the extrusion temperature of the extruder is not more than (melting point of polyethylene resin +35 ℃) and the residence time of the polyethylene resin composition in the extruder is controlled to 2 to 10 min.

9. The method for preparing the elastomer modified pre-crosslinked polyethylene composite film layer according to claim 7, wherein when the fiber felt is a carbon fiber felt (31), the fiber felt is subjected to pre-dip pre-dipping before compounding; the pre-immersion liquid is polyvinyl alcohol, polyvinyl acetate or acrylic acid.

10. An automatic leakage detection elastomer modified pre-crosslinked polyethylene anticorrosion structure is characterized by comprising a PE base layer membrane system (30), wherein the PE base layer membrane system (30) adopts the elastomer modified pre-crosslinked polyethylene composite membrane layer according to any one of claims 1 to 6, a fiber felt of the elastomer modified pre-crosslinked polyethylene composite membrane layer adopts a carbon fiber felt (31), one side of the carbon fiber felt (31) is fixed on the inner wall of a substrate (10) through a bonding agent (20), a PE membrane layer lead (38) in the elastomer modified pre-crosslinked polyethylene composite membrane layer is connected with a current exchanger (37), and the current exchanger (37) is sequentially connected with a power supply (36), an alarm (35), a liquid connecting line (34) and a liquid sensing device (39); in use, the liquid sensing device (39) is disposed within the substrate (10).

11. The automatic leak hunting elastomer-modified pre-crosslinked polyethylene corrosion protective structure as claimed in claim 10, wherein a recess on the inner wall of said base (10) is filled with a mending material (12); the patching material (12) is at least one of mortar and putty; the adhesive (20) is epoxy daub or polyurethane asphalt daub.

12. The self-leak-checking elastomer-modified pre-crosslinked polyethylene corrosion protective structure according to claim 10, wherein the inner wall of the base body (10) is coated with a primer; the primer is epoxy primer or polyurethane primer.

13. The automatic leak hunting elastomer-modified pre-crosslinked polyethylene corrosion protection structure as claimed in claim 10, wherein all of said PE film layer wires (38) are connected in parallel and then connected to a current exchanger (37); or each PE film layer lead (38) is connected with a current exchanger (37), each current exchanger (37) is connected with an alarm (35) or all the current exchangers (37) are connected in parallel and then connected with an alarm (35).

14. The automatic leakage detection elastomer modified pre-crosslinked polyethylene anticorrosion structure as set forth in claim 10, wherein the PE-based membrane system (30) is an elastomer modified pre-crosslinked polyethylene composite membrane layer of an integral structure or a spliced structure formed by splicing a plurality of elastomer modified pre-crosslinked polyethylene composite membrane layers, when the spliced structure is adopted, the edges of adjacent elastomer modified pre-crosslinked polyethylene composite membrane layers are overlapped, and the width d of the overlapped part is 5-100 mm; the elastomer modified pre-crosslinked polyethylene composite film layer on one side close to the base body (10) in the overlapped part only comprises an elastic PE film layer (32); the elastomer modified pre-crosslinked polyethylene composite film layer is fixed on a base body (10) through an adhesive (20), then a hot-melt welding machine is used for carrying out hot-melt welding on the overlapped part, then a hot-melt welding strip is used for carrying out repair welding at the splicing position of the adjacent elastomer modified pre-crosslinked polyethylene composite film layer as required, the splicing seam is completely sealed, and the specific process of the hot-melt welding is as follows: and preheating the overlapped part for 5-120 s, and then carrying out hot-melt welding at the temperature of between the melting point of the polyethylene resin and (the melting point of the polyethylene resin and 55 ℃) and at the temperature of not less than 480 ℃.