KR101116043B1 - Thermo plastic elastomer and process for self adhesive rubberized asphalt sheet - Google Patents

Abstract

PURPOSE: A manufacturing method of a waterproof sheet is provided to obtain a waterproof sheet of which moldable hardness is in the region of ASTM Shore A through calender process without additional cross-linking process. CONSTITUTION: A manufacturing method of a waterproof sheet comprises: a step of uniformly mixing a dispersant, inorganic materials into a mixture; and a step of calender process using twin screw extruder capable of recycling scraps after using without additional crosslinking process. The mixture comprises 20-50 wt% hydrogenated rubber and a modified propylene group, 15-45 wt% of a propylene group modified by metallocene and Ziegler-nata, 10-35 wt% of a rubber group in which natural rubber and synthetic rubber are modified, and 5-10 wt% of a C9 group improving the adhesion of an olefin group.

Description

Thermoplastic Elastomer and process for Self adhesive rubberized asphalt sheet

The present invention relates to a manufacturing method of mixing a thermoplastic elastomer and recycled rubber using an olefinic polymer. More specifically, the molding of the product is possible without kneading and a separate crosslinking process using a thermoplastic plastic and recycled rubber. The present invention relates to a method for manufacturing a waterproof sheet by mixing an olefinic thermoplastic elastomer and a recycled rubber to enable recycling of scrap after use.

Generally, the vulcanized rubber is manufactured through complex steps such as kneading step of the compound, sheet forming step of the kneaded product, cutting step of the molded sheet, and molding and vulcanizing the product using the cut sheet.

Thermoplastic elastomer (TPE) is a thermoplastic material that is generally an elastomer such as rubber at room temperature and flows by heating unlike the above rubber, and refers to a material that can be processed by the same processing method as a general thermoplastic resin. to be.

These thermoplastic elastomers can be distinguished from the one made of a molecular structure similar to rubber in the process of polymerizing the thermoplastic resin according to the manufacturing method, and a mixture of the already produced thermoplastic resin and rubber.

The thermoplastic elastomer of the present invention corresponds to a mixture of a double thermoplastic resin and a recycled rubber, which is classified into a continuous phase and a discontinuous phase according to its characteristics. Particularly, in the case of the continuous phase, the material has a rubbery elasticity and feel at room temperature. It is made of non-crosslinked rubber so that it can be represented.

That is, the rubber is present in a state similar to a filler such as talc (TALC), calcium carbonate, and carbon black from the standpoint of the thermoplastic resin, and the recycled rubber in such a state is drastically reduced in mechanical properties as it is added to the thermoplastic resin. In addition, the mechanical properties of the thermoplastic resin including the recycled rubber can be said to be greatly influenced by the recycled rubber, the particle size of the rubber, the type of rubber and the affinity between the recycled rubber and the thermoplastic resin.

In addition, in order to effectively disperse a large amount of rubber in a relatively small amount of thermoplastic resin, there is a need for methods of reducing the size of rubber particles by using commercially available materials of two materials or by fine grinding.

Meanwhile, sulfur and phenol resins have generally been used for the crosslinking of olefin copolymer rubbers. However, sulfur and phenol resins cause severe odor and coloration of the product, especially in rubber molecules. When the number of double bonds is small (2 wt% of the total), there is a problem in that the crosslinking time is long because the crosslinking efficiency is lowered.

In addition, in the case of the phenolic resin, since it uses a crosslinking aid containing a halogen that is harmful to the human body, there is a restriction on the use of the product, which is a direct cause of shortening the life of the processing equipment.

Therefore, the present invention is water-resistant by mixing the olefin-based thermoplastic elastomer and the recycled rubber to improve the affinity with the thermoplastic resin while minimizing the residual amount of sulfur by checking the desulfurization state of the discontinuously distributed recycled rubber as the filler described above The object is to provide a method for producing a sheet.

In addition, another object of the present invention is to provide an environmentally friendly olefin-based thermoplastic elastomer capable of molding the product without undergoing a separate crosslinking process at the same time as kneading.

In the present invention, a twin screw extruder capable of combining a kneader, a single screw extruder, and a screw is used in parallel to achieve the above object. Ingredients were used selectively and the composition ratios were adjusted.

In addition, in the final product so that there is no unusual odor in the extrusion operation to deodorize using a holding device and additives were also used selectively.

In order to achieve the above object effectively, the olefin-based thermoplastic elastomer of the present invention and the elastomer mixed with recycled rubber are 20-50wt% of propylene-based modified rubber and propylene-based 15-modified with Metallocene and Ziegler-Nata in thermoplastic resin. 45wt%, patterned viscosity modified natural rubber and synthetic rubber ML1 + 4 (125 ℃) 35, tensile strength 77 N / mm ² , 10-35wt% rubber modified Olefin based adhesive with 257% elongation It is composed of a mixture of 5-10wt% C9 system to increase and is characterized in that the mixture further comprises 5-15wt% dispersant, inorganic.

In addition, the olefin-based thermoplastic resin is characterized in that the MFR is propylene modified with hydrogenated rubber in the range of 9-17 g / 10min.

The rubber may further contain 5-15 wt% of dispersant and inorganic substances in addition to 40-50 wt% of two or more carbon components having 6-9 carbon atoms, 25 wt% of natural rubber, and 35 wt% of synthetic rubber. To be characterized.

In addition, the rubber is characterized in that the lump form consisting of a particle size of 50-70㎛.

In addition, the modified propylene copolymerized with the olefin component is MFI (230 ℃, 2160 g) is 2.0-8.0 g / 10min, the melting temperature is 180 ℃-230 ℃ characterized by being modified with an aliphatic monomer containing 3-9 carbon atoms Should be.

The manufacturing method of mixing the olefin thermoplastic elastomer and recycled rubber of the present invention is 20-50wt% of propylene-based rubber and modified propylene-based propylene-based 15-45wt% by metallocene and Ziegler-Nata by kneader process. , Natural rubber and Synthetis rubber with pattern viscosity ML1 + 4 (125 ℃) 35, Tensile strength 77 N / mm ² , Modified rubber based on physical properties of elongation rate of 257% 10-35wt%, C9 based to improve Olefin adhesion Separate cross-linking process using a twin screw extruder consisting of 5-10wt% of mixture and the first step of dispersing agent and inorganics 5-15wt% uniformly into the mixture and one screw can be a combination of several fragmented screws It characterized in that it comprises a second step to enable molding through a calendar (Calender) process without going through.

The thermoplastic elastomer mixed with recycled rubber according to the present invention is composed of a continuous thermoplastic resin and a discontinuous recycle rubber finely dispersed evenly in the material, preferably mixed with hydrogenated rubber and modified propylene. 20-50wt% and 40-70wt% of natural and synthetic rubber-based components that give rubbery elasticity have at least 6-9 carbon atoms, and C9, which enhances adhesion to improve interfacial affinity with the thermoplastic resin and recycled rubber. And 5-10 wt% of the polymer. 50 wt% of the thermoplastic resin includes 5-10 wt% of the C9 polymer to increase adhesion to increase the interfacial affinity of the thermoplastic resin and the olefin copolymer rubber. If it is more than%, the content of natural and synthetic rubbers is relatively low, so the natural and synthetic rubbers are used only for impact resistance of plastics. Since it does not get the actual feel or hardness of the rubber, it is impossible to maintain the optimum conditions. To express low hardness of shore 50-70A such as general vulcanization or soft pvc at room temperature, the content ratio of the thermoplastic resin is 50wt. The thermoplastic resin is preferably made of hydrogenated rubber and modified propylene having a MFI (Melt flow index) in the range of 9-17 g / 10min. To improve, it is more preferable to use propylene having an MFI in the range of 2-8 g / 10 min.

And the natural, synthetic co-polymerized recycled rubber used to give rubbery elasticity is preferably 40-70wt% of the first component having 6-9 carbon atoms and 20-50wt% of the second component having 10-13 carbon atoms; It is prepared by copolymerizing 10-50 wt% of the third component having 11-14 carbon atoms. At this time, in order to further improve the properties of the final product, 35-45 wt% of the first component and 35-40 wt% of the second component, It is more preferable to use 15-45 wt% of three components.

In addition, as described above, the thermoplastic elastomer mixed with the recycled rubber of the present invention has a final physical property determined according to the physical properties of the rubber to be added, so that the recycled rubber has a viscosity between 35-90 g / cm? S at a temperature of 135 ° C. It is more preferable to use recycled rubber.

In addition, the C9 system added to increase the interfacial affinity of the thermoplastic resin and recycled rubber has a Melt Viscosity (120 ° C.) of 50000 cps.

On the other hand, when processing a product such as a sheet (sheet) using a thermoplastic elastomer mixed with recycled rubber according to the present invention, various fillers are used to impart processing stability. There are various kinds of fillers such as carbon, clay, calcium carbonate, jute, etc., but these are selectively used in consideration of the color and physical properties of the final product.

In this case, it is preferable to use a white color which is easy to color in the colored product, and when the particles of the filler to be used are too large, it is preferable to use an average particle diameter of 0.5-10 μm in the case of extrusion. The thermoplastic elastomer mixed with the recycled rubber further contains rubber oil to facilitate the hardness control of the product. The oil preferably has a relatively good affinity for the polymer. Paraffin-based oil is used. If the molecular weight of the oil is too low, the plasticization efficiency is good, but the molecular weight becomes small, so that physical properties change due to volatilization during use, and plasticity efficiency is decreased and handling becomes inconvenient if the viscosity is high. So preferably used between 300-850 and especially between 450-750 When used, it can give better processing characteristics and plasticity.

Method for producing a thermoplastic elastomer mixed with recycled rubber according to the present invention is a copolymer of two or more kinds of carbon black and olefin component having 20-50wt% polyolefin-based thermoplastic resin and 6-8 non-continuous carbons. By adding 10-35wt% of recycled rubber and 5-10wt% of C9 system to increase the adhesion to reduce the mechanical property degradation caused by discontinuous rubber by increasing the affinity at the interface between the polyolefin-based thermoplastic resin and rubber In the kneader process, the first step of uniformly mixing additives such as filler and oil, and the sheet process produced through the calender process using a twin screw extruder using a chemical mechanism. It is configured to include a second step.

The first step is 160-250, which is relatively higher than the melting temperature of the thermoplastic resin component by using a kneading screw, which is a conventional full flight screw to improve the mixing efficiency by improving the mixing efficiency of the extruder and improving the productivity of the mixture. When the mixing temperature is less than 160 ° C, excessive energy consumption due to unmelting of the thermoplastic resin as well as a relatively small amount of thermoplastic resin lacks the viscosity necessary to achieve continuity. If the mixing temperature is higher than 250 ℃, the thermal decomposition of each component and the physical properties of the product are inhibited as well as the coloration and vertical carbonization occur, preferably at a temperature of 160-250 ℃. Is to enforce.

In addition, the first stage mainly uses a single screw extruder. The single screw extruder increases the shear pressure at the screw and cylinder interface by increasing the pressure in the cylinder inside the extruder, so that the mixing efficiency is further enhanced. It is preferable to mix three to six sheets of steel screen (steel screen) having a thickness of 250 μm or less.

In addition, in the kneader process, several kinds of materials should be added at the same time because of their characteristics.

In the second step of the twin screw extruder process, inter-meshing is performed so that all screw combinations in the cylinder can be freely designed to finely and uniformly disperse the particles of recycled rubber and to improve the dispersibility of the mixed additives. This makes it possible to use a twin screw extruder equipped with a screw.

As described above, the thermoplastic elastomer mixed with the recycled rubber of the present invention determines the overall physical characteristics of the particle size of the recycled rubber present in the thermoplastic resin, so that the whole mounted on the twin-screw extruder to efficiently control the particle size of the recycled rubber 30-60% of the number of screws is appropriately combined with the kneading blocks (gneading blocks) that can give a high shear force for the miniaturization of the recycled rubber particles to break the recycled rubber particles into fine particles.

At this time, when the number of kneading blocks is insufficient, it is difficult to provide sufficient shear force for crushing rubber particles, and when the number is excessively excessive, excessive heat and shear force are generated inside the cylinder, thereby causing the molecular chain of each component to shear and physical properties. Problems that cause the degradation and discoloration of the.

Therefore, after the screw, insert three to four disk-type screws or counter-rotating screws to seal the molten material after the screw to induce some stagnation so that fine rubber particles can be evenly dispersed in the thermoplastic resin. By inducing melt sealing to increase the dispersion efficiency.

In addition, the softening agent for controlling the hardness of the material is added using a double thread screw constituting 30-50% of the total screw after the dispersion of fillers, processing aids, etc. and finer rubber particles are completed. Double-threaded screw is designed to be melt-sealed again after the softener is added to increase the efficiency when an excess softener is added (more than 45wt% of the total weight).

In order to achieve this mixing, the cylinder temperature of the extruder is partially controlled by dividing the total cylinder temperature into 15 zones, and one cylinder can contain 3-4 screw pieces, so that the melt temperature is 160-230 ℃. Set it to

If the rotation speed of the screw is too slow, the size of the rubber particles becomes large overall, which tends to deteriorate the surface condition at the surface and thin layer, especially in the case of extruded products, and if the rotation speed is too fast due to insufficient kneading time. Since the elastic recovery force of the product tends to be reduced, in the present invention, the residence time of the injected material is not less than 1 minute and not more than 2 minutes in consideration of such matters, and at the same time, the high shear force is imparted.

At this time, the rotation speed of the screw is set to about 300-600rpm.

Therefore, according to the thermoplastic elastomer using the olefin-based polymer mixed with the recycled rubber according to the present invention and the manufacturing method thereof, the moisture permeability is high and the hardness that can be formed through a calender process without going through a separate crosslinking process is ASTM Shore A You can get a waterproof sheet in the area of.

Therefore, it can be used in products requiring high moisture barrier properties, and also has excellent weather resistance by using olefinic polymer, so it can be applied to self-adhesive rubberized asphalt waterproof sheet products of exposure and non-exposure.

It is also applicable to the manufacture of most orders and waterproof products requiring injection, extrusion, calendar ring, and tide processing.

When the various raw materials and additives described above are manufactured by the method proposed by the present invention within a certain range, the objects of the present invention can be effectively obtained, and more details will be described through the following examples.

Examples using this are in Table 7 to Table 20 and the company that conducted the test was carried out at the Korea Research Institute of Petroleum Technology.

The components and properties used are shown in Tables 1 to 6, respectively, as follows.

Table 1

Component A (Hydrogenated Olefin Polymers)

Table 2

Component B (Thermo Plastic Polymers)

Table 3

Component C (Metallocene Modified Olefin Polymers)

Table 4

Component D (RUBBER)

Table 5

Component E (Tackifying Modified Olefin Polymers)

Table 6

Filler

Examples using this are in Table 7 to Table 20 and the company that conducted the test was carried out at the Korea Research Institute of Petroleum Technology.

The components A, B, C, and D were mixed under the conditions of 160-230 ° C. using a 40m / m Twin-Extruder, and the mechanical properties were observed. The results are shown in Table 8. As shown in the test results, it can be seen that the physical property decreases in the tension and elongation of the temperature-dependent performance.

Table 7

Table 8

Measurement of Physical Properties of Waste Tire Sheet Samples

Similar to Example 1, but with different thicknesses of specimens. The conditions of Twin-Extruder were the same, and the results of the mechanical properties were observed and the results are shown in Table 10. It can be seen that the degradation appears.

Table 9

Table 10

Measurement of Physical Properties of Waste Tire Sheet Samples

In order to improve the properties of temperature-dependent performance, the contents of components A and C were increased and the contents of component D were lowered and mixed. The screw rotation speed was 350 RPM during kneading and dispersion, and the input speed of the components was 800 kg / h.

Changes in mechanical properties are shown in Table 12.

Table 11

Table 12

Measurement of Physical Properties of Waste Tire Sheet Samples

As shown in Example 3, the improvement of the physical properties of the temperature dependent performance is not improved, so the content of component A is higher, components B and C are reduced, and component F is increased.

When kneading and dispersing, the rotation speed of Twin-Extruder was 350RPM and the temperature was 160-250 ℃.

The mechanical properties of the specimens are shown in Table 14.

Table 13

Table 14

Measurement of Physical Properties of Waste Tire Sheet Samples

The physical properties of the temperature-dependent performance shown in Example 4 were close to the standard, and the components A and B were reduced evenly and the content of component D was increased to reduce the cost in mass production. Same as Example 4), the change in mechanical properties is shown in Table 16.

Table 15

Table 16

Measurement of Physical Properties of Waste Tire Sheet Samples

As shown in (Example 5), the component content and change for cost reduction showed a decrease in the overall physical properties. In this example, the contents of components B and C were increased, component D was stabilized flat, and the rotation speed of the Twin-Extruder was 350 RPM and the temperature was 160 ~ 230 ℃.

Table 17

Table 18

Measurement of Physical Properties of Waste Tire Sheet Samples

In order to stabilize the overall physical properties and to improve the physical properties, in particular, the temperature dependent performance, the components B and C were improved in small amounts. The rotation speed and temperature conditions of the twin-extrude are the same as in Example 6. Shown in

Table 19

Table 20

Measurement of Physical Properties of Waste Tire Sheet Samples

As shown in Table 20, a satisfactory result of the improvement of physical properties of the waterproof sheet manufactured by the present invention was obtained, and the property criteria of Table 20 are in accordance with KS F 4934.

Regarding the waterproof sheet manufactured by the present invention, the test data of the example of Table 20 on October 11, 2010 was confirmed, and in November 2010, the Korea Petroleum Industries Co., Ltd. Signed an exclusive supply agreement for civil engineering, building sheet production, supply, and development of mixed thermoplastic materials (including powder), and signed an exclusive supply contract for the self-supporting rubberized asphalt manufactured by the present invention. Waterproof sheets are intended to replace expensive and imported products such as EPDM and butyl rubber (see copy of MOU).

Claims (4)

delete delete delete 20-50wt% propylene-based rubber modified by single screw extruder with screw including partially mixed screw, propylene-based 15-45wt% modified by metallocene and Ziegler-Nata, rubber modified natural rubber and synthetic rubber Composed of a mixture of 10-35wt% system and 5-10wt% C9 system which improves the adhesion of Olefin system, the first step of uniformly mixing the dispersant, inorganics, etc. in the mixture and the combination of several fragmented screws By using a twin-screw extruder that can be made without a separate cross-linking process through the calender (calender) process, it is possible to form the product as well as comprising a second step to enable the recycling of scrap after use Method for producing an olefin-based thermoplastic elastomer and waterproof sheet mixed with recycled rubber.