A micro-crosslinking master batch, a preparation method thereof, a modified PERT and application thereof

Abstract

The application provides a kind of micro-crosslinking master batch and its preparation method, modified PERT and its application, belong to pipe manufacturing field.The application provides a kind of micro-crosslinking master batch, by mass fraction, the micro-crosslinking master batch includes the following preparation raw materials: first PERT 100 parts;Antioxidant 0.4-1 part;Peroxide crosslinking agent 0.02-0.18 parts;The crosslinking degree of the micro-crosslinking master batch is 1.5-2.5%.The free radical generated by peroxide crosslinking agent can make PERT become active PE macromolecular free radical, form network structure.Network structure makes the molecular movement of pipe material become difficult in the process of cooling, thereby reduces shrinkage rate;By controlling crosslinking degree, so that micro-crosslinking master batch occurs partial crosslinking, the compatibility of first PERT that has not occurred crosslinking with second PERT can be improved, and then the PERT that has occurred crosslinking is uniformly dispersed in second PERT, further reduces shrinkage rate.

Description

Technical Field

[0001] The present invention relates to the field of pipe manufacturing, and in particular to a micro-crosslinked masterbatch and a preparation method thereof, modified PERT and applications thereof. Background Art

[0002] Heat-resistant polyethylene, also known as PERT, is a non-cross-linked polyethylene material. PE-RT retains the low-temperature resistance of PE pipe while improving its creep resistance and strength at high temperatures. In recent years, it has become an emerging material for floor heating pipes. However, PERT floor heating pipes suffer from dimensional shrinkage after they come off the production line. Summary of the Invention

[0003] The present invention provides a micro-crosslinked masterbatch and a preparation method thereof, modified PERT and applications thereof. When a pipe is prepared using the modified PERT prepared from the micro-crosslinked masterbatch of the present invention, the shrinkage rate of the pipe is low.

[0004] The present invention provides a micro-crosslinked masterbatch, which comprises the following raw materials, calculated by weight:

[0005]

[0006] Preferably, the peroxide crosslinking agent includes one or more of acyl peroxides, hydroperoxides, dialkyl peroxides, ester peroxides, ketone peroxides and dicarbonate peroxides.

[0007] Preferably, the antioxidant includes one or more of antioxidant 1010 , antioxidant 1076 and antioxidant 168 .

[0008] Preferably, when the antioxidant includes antioxidant 1010, antioxidant 1076 and antioxidant 168, the mass ratio of antioxidant 1010, antioxidant 1076 and antioxidant 168 is (3.5-4.5):(1.5-2.5):(0.5-1.5).

[0009] Preferably, the particle size of the micro-crosslinked masterbatch is 5 to 50 μm.

[0010] The present invention also provides a method for preparing the micro-crosslinked masterbatch described in the above technical solution, comprising the following steps:

[0011] Mixing raw materials for preparing micro-crosslinked masterbatch, extruding, crosslinking and granulating to obtain the micro-crosslinked masterbatch;

[0012] The cross-linking temperature is 300-350° C., and the cross-linking time is 0.75-1.2 minutes.

[0013] The present invention also provides a modified PERT, which comprises the following components in parts by mass:

[0014]

[0015] The micro-crosslinked masterbatch is the micro-crosslinked masterbatch described in the above technical solution or the micro-crosslinked masterbatch prepared by the preparation method described in the above technical solution.

[0016] Preferably, the glass microspheres are hollow glass microspheres with a particle size of 30 to 100 μm and a density of 0.1 to 0.7 g / cm 3 .

[0017] Preferably, the models of the silane coupling agent include one or more of Japan Shin-Etsu KBE-846, American Dow Corning Z-6940, Chenguang New Material KH-550, Chenguang New Material KH-560 and Chenguang New Material KH-570.

[0018] The present invention also provides the use of the modified PERT described in the above technical solution in the preparation of floor heating pipes

[0019] The free radicals generated by the peroxide crosslinking agent can attack polyethylene macromolecular chains, capturing hydrogen atoms from the chains and transforming them into active PE macromolecular free radicals. When these PE macromolecular free radicals meet, they combine to form carbon-carbon crosslinks, forming a network structure. This network structure hinders molecular movement during the pipe cooling process, thereby reducing shrinkage. Furthermore, by controlling the degree of crosslinking, the present invention partially crosslinks the micro-crosslinked masterbatch, improving the compatibility of the uncrosslinked first PERT with the second PERT. This allows the crosslinked PERT to be evenly dispersed in the second PERT, further reducing shrinkage.

[0020] Because spherical objects are isotropic, glass microbeads can overcome the drawback of inconsistent shrinkage rates in different parts due to orientation and can reduce shrinkage. Glass microbeads themselves have an extremely high refractive index, which can reflect visible light from the light source and enhance light transmission, thereby increasing the brightness and transparency of the pipe. Low-shrinkage, high-transparency PERT floor heating pipes provide excellent stability: First, the actual number of meters produced can be precisely controlled during the production process, eliminating the deliberate lengthening of production due to shrinkage and saving costs; second, the product length and outer diameter can be guaranteed to remain unchanged during storage, maintaining the product's appearance and quality; third, changes in the medium temperature during use will not cause stress shrinkage in the pipe, which in turn will cause the connection to fall off and affect safety. DETAILED DESCRIPTION

[0021] The present invention provides a micro-crosslinked masterbatch, which comprises the following raw materials, calculated by weight:

[0022]

[0023] In parts by mass, the raw materials for preparing the micro-crosslinked masterbatch of the present invention include 100 parts of a first PERT; the model of the first PERT preferably includes one or more of Borouge 3466R, Dushanzi 3606, Lanzhou Petrochemical L5050, Lanzhou Petrochemical 3010, Daqing 3711 and Qilu 32F.

[0024] Based on the mass fraction of the first PERT, the raw materials for preparing the micro-crosslinked masterbatch of the present invention include 0.4 to 1 parts of antioxidants. In a specific embodiment of the present invention, the mass fraction of the first PERT can be 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 parts; the antioxidant preferably includes one or more of antioxidant 1010, antioxidant 1076 and antioxidant 168; when the antioxidant includes antioxidant 1010, antioxidant 1076 and antioxidant 168, the antioxidant includes antioxidant 1010, antioxidant 1076 and antioxidant 168. The mass ratio of the antioxidant is preferably (3.5-4.5): (1.5-2.5): (0.5-1.5). In a specific embodiment of the present invention, the mass ratio of the antioxidant 1010, antioxidant 1076 and antioxidant 168 can be 4:2:1.

[0025] When the antioxidant preferably includes two or three of antioxidant 1010, antioxidant 1076 and antioxidant 168, the preparation method of the antioxidant preferably includes: mixing two or three of antioxidant 1010, antioxidant 1076 and antioxidant 168; the mixing temperature is preferably 45°C, and the mixing time is preferably 10 minutes; the mixing is preferably carried out under stirring conditions, and the stirring speed is preferably 15 r / min.

[0026] Based on the mass fraction of the first PERT, the raw materials for preparing the micro-crosslinked masterbatch of the present invention include 0.02 to 0.18 parts of a peroxide crosslinking agent. In a specific embodiment of the present invention, the mass fraction of the peroxide crosslinking agent can be 0.02 parts, 0.03 parts, 0.04 parts, 0.05 parts, 0.06 parts, 0.07 parts, 0.08 parts, 0.09 parts, 0.1 parts, 0.11 parts, 0.12 parts, 0.13 parts, 0.14 parts, 0.15 parts, 0.16 parts, 0.17 parts or 0.18 parts; the peroxide crosslinking agent preferably includes: acyl peroxide, hydroperoxide, dialkyl peroxide The invention relates to one or more of compounds, ester peroxides, ketone peroxides and dicarbonate peroxides; the acyl peroxide preferably includes benzoyl peroxide and / or lauroyl peroxide; the hydroperoxide preferably includes cumene hydroperoxide and / or tert-butyl hydroperoxide; the dialkyl peroxide preferably includes di-tert-butyl peroxide and / or dicumyl peroxide; the ester peroxide preferably includes tert-butyl perbenzoate and / or tert-butyl pervalerate; the ketone peroxide preferably includes methyl ethyl ketone peroxide and / or cyclohexanone peroxide; the dicarbonate peroxide preferably includes diisopropyl peroxydicarbonate and / or dicyclohexyl peroxydicarbonate.

[0027] In the present invention, the crosslinking degree of the micro-crosslinked masterbatch is 1.5-2.5%. In a specific embodiment of the present invention, the crosslinking degree of the micro-crosslinked masterbatch can be 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2.0%, 2.1%, 2.2%, 2.3%, 2.4% or 2.5%.

[0028] The present invention also provides a method for preparing the micro-crosslinked masterbatch described in the above technical solution, comprising the following steps:

[0029] Mixing raw materials for preparing micro-crosslinked masterbatch, extruding, crosslinking and granulating to obtain the micro-crosslinked masterbatch;

[0030] The cross-linking temperature is 300-350° C., and the cross-linking time is 0.75-1.2 min.

[0031] In the present invention, the mixing is preferably carried out in a high-speed plastic mixer, and the rotation speed of the high-speed plastic mixer is preferably 800 r / min.

[0032] In the present invention, the extrusion is preferably carried out in a screw extruder; the speed of the screw in the screw extruder is preferably 40 to 50 r / min; from the head to the tail, the screw extruder preferably includes first to fourth temperature zones; the temperature of the first temperature zone is preferably 145°C ± 5°C, the temperature of the second temperature zone is preferably 145°C ± 5°C, the temperature of the third temperature zone is preferably 135°C ± 5°C, and the temperature of the fourth temperature zone is preferably 130°C ± 5°C; the extrusion speed of the screw extruder is preferably 5 to 8 m / min.

[0033] In the present invention, the cross-linking temperature is 300-350°C. In a specific embodiment of the present invention, the cross-linking temperature may be 300°C, 310°C, 320°C, 330°C, 340°C or 350°C; the cross-linking time is 0.75-1.2 min. In a specific embodiment of the present invention, the cross-linking time may be 0.75 min, 0.8 min, 0.9 min, 1 min or 1.2 min.

[0034] The present invention also provides a modified PERT, which comprises the following components in parts by mass:

[0035]

[0036] The micro-crosslinked masterbatch is the micro-crosslinked masterbatch described in the above technical solution or the micro-crosslinked masterbatch prepared by the preparation method described in the above technical solution.

[0037] In terms of parts by mass, the components of the modified PERT of the present invention include 87 to 94.3 parts of the second PERT. In a specific embodiment of the present invention, the mass proportion of the second PERT in the modified PERT can be 87, 88, 89, 90, 91, 92, 93, 94 or 94.3 parts; the model of the second PERT preferably includes one or more of Borouge 3466R, Dushanzi 3606, Lanzhou Petrochemical L5050, Lanzhou Petrochemical 3010, Daqing 3711 and Qilu 32F.

[0038] Based on the mass fraction of the second PERT, the components of the modified PERT of the present invention include 5 to 10 parts of glass microspheres. In a specific embodiment of the present invention, the mass fraction of the glass microspheres in the modified PERT can be 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts; the glass microspheres are preferably hollow glass microspheres, and the particle size of the glass microspheres is preferably 60 μm, and the density is preferably 0.20 g / cm 3 ; The glass microspheres preferably include GS20 produced by China Steel Group Ma'anshan Mining Institute New Materials Technology Co., Ltd.

[0039] Based on the mass fraction of the second PERT, the components of the modified PERT of the present invention include 0.2 to 1 parts of a silane coupling agent. In a specific embodiment of the present invention, the mass fraction of the silane coupling agent in the modified PERT can be 0.2 parts, 0.3 parts, 0.4 parts, 0.5 parts, 0.6 parts, 0.7 parts, 0.8 parts, 0.9 parts or 1 parts; the silane coupling agent preferably includes one or more of Japan Shin-Etsu KBE-846, American Dow Corning Z-6940, Chenguang New Materials KH-550, Chenguang New Materials KH-560 and Chenguang New Materials KH-570.

[0040] The present invention also provides the use of the modified PERT described in the above technical solution in the preparation of floor heating pipes.

[0041] In the present invention, the preparation of the warm pipe preferably includes the following steps:

[0042] The modified PERT raw materials are mixed and then extruded, vacuum-adsorbed and shaped, cooled, drawn and cut to obtain the floor heating pipe.

[0043] In the present invention, the temperature of the barrel used for extrusion during the extrusion is preferably 175-200°C. In a specific embodiment of the present invention, the temperature of the barrel may be 175°C, 180°C, 190°C or 200°C; the temperature of the mold used is preferably 190-215°C. In a specific embodiment of the present invention, the temperature of the mold may be 175°C, 180°C, 190°C, 200°C, 210°C or 210°C.

[0044] The micro-crosslinked masterbatch and its preparation method, modified PERT and its application provided by the present invention are described in detail below with reference to the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

[0045] The PERT is Borouge 3466R, the silane coupling agent is Japan's Shin-Etsu KBE-846, and the glass microspheres are GS20 from China Steel Group Ma'anshan Mining Institute New Materials Technology Co., Ltd.

[0046] Example 1

[0047] Preparation of compound antioxidants

[0048] The compound antioxidant was prepared by cold mixing antioxidant 1010: antioxidant 1076: antioxidant 168 in a ratio of 4:2:1, with a rotation speed of 15 r / min, a cold mixing time of 10 min, and a cold mixing temperature of 45°C.

[0049] Preparation of micro-crosslinked masterbatch

[0050] PERT resin, compound antioxidant, and peroxide crosslinking initiator (di-tert-butyl peroxide DTBP) were added into a plastic high-speed mixer according to the formula ratio in Table 1, and the speed was 800 r / min. After high-speed stirring and uniform mixing, a premix was obtained.

[0051] The uniformly mixed premix was extruded into strips through a single-screw extruder at a screw speed of 50 r / min. The temperatures in each section of the extruder were set as follows: Zone 4: 130°C ± 5°C, Zone 3: 135°C ± 5°C, Zone 2: 140°C ± 5°C, and Zone 1: 145°C ± 5°C. The extruded strips were then passed through a haul-off machine at a speed of 8 m / min through a 6-m-long infrared cross-linking furnace set at 300°C. The strips were then cut into uniform pellets using a cold cutter to produce the micro-cross-linked masterbatch.

[0052] Examples 2 to 4 and Comparative Examples 1 to 5

[0053] The formulas of Examples 2 to 4 and Comparative Examples 1 to 5 are shown in Table 1, and the rest are the same.

[0054] Table 1 Formulations and MFR of Examples 1 to 4 and Comparative Examples 1 to 5

[0055]

[0056] Application Example 1

[0057] 92 parts of PERT resin, 0.6 parts of the micro-crosslinked masterbatch of Example 1, 6.6 parts of high-performance hollow glass microspheres, and 0.8 parts of a silane coupling agent were uniformly mixed in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C). After vacuum adsorption shaping, cooling in a water tank, pulling, and cutting, the pipe product was obtained.

[0058] Application Example 2

[0059] 90 parts of PERT resin, 1.1 parts of the micro-crosslinked masterbatch of Example 2, 8 parts of high-performance hollow glass microspheres, and 0.9 parts of a silane coupling agent were uniformly mixed in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C). After vacuum adsorption shaping, cooling in a water tank, pulling, and cutting, the pipe product was obtained.

[0060] Application Example 3

[0061] 88 parts of PERT resin, 1.8 parts of the micro-crosslinked masterbatch of Example 3, 9.2 parts of high-performance hollow glass microspheres, and 1 part of a silane coupling agent were uniformly mixed in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C). After vacuum adsorption shaping, cooling in a water tank, pulling, and cutting, the pipe product was obtained.

[0062] Application Example 4

[0063] 88 parts of PERT resin, 2 parts of the micro-crosslinked masterbatch of Example 4, 9 parts of high-performance hollow glass microspheres, and 1 part of a silane coupling agent were uniformly mixed in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C). After vacuum adsorption shaping, cooling in a water tank, pulling, and cutting, the pipe product was obtained.

[0064] Comparative Application Example 1

[0065] 91.5 parts of PERT resin, 1 part of the micro-crosslinked masterbatch of Comparative Example 1, 7 parts of high-performance hollow glass microspheres, and 0.5 parts of a silane coupling agent were mixed uniformly in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C). The mixture was then shaped by vacuum adsorption, cooled in a water tank, pulled, and cut to obtain a pipe product.

[0066] Comparative Application Example 2

[0067] 92.8 parts of PERT resin, 0.7 parts of the micro-crosslinked masterbatch from Comparative Example 2, 6 parts of high-performance hollow glass microspheres, and 0.5 parts of a silane coupling agent were uniformly mixed in a high-speed mixer at a temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C). The mixture was then shaped by vacuum adsorption, cooled in a water tank, pulled, and cut to obtain a pipe product.

[0068] Comparative Application Example 3

[0069] 90 parts of PERT resin, 0.9 parts of the micro-crosslinked masterbatch of Comparative Example 3, 8.5 parts of high-performance hollow glass microspheres, and 0.6 parts of a silane coupling agent were mixed uniformly in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw production equipment for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C).

[0070] Comparative Application Example 4

[0071] 89.8 parts of PERT resin, 1.5 parts of the micro-crosslinked masterbatch of Comparative Example 4, 8 parts of high-performance hollow glass microspheres, and 0.7 parts of a silane coupling agent were mixed uniformly in a high-speed mixer at a hot mixing temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw production equipment for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C).

[0072] Comparative Application Example 5

[0073] 91 parts of PERT resin, 1.2 parts of the micro-crosslinked masterbatch of Comparative Example 5, 7 parts of high-performance hollow glass microspheres, and 0.8 parts of a silane coupling agent were mixed uniformly in a high-speed mixer at a temperature of 70-80°C. After uniform mixing, the mixture was fed through a feeder into a single-screw extruder for extrusion molding (barrel temperature of 175-200°C, die temperature of 190-215°C).

[0074] The transparency and shrinkage of the pipes obtained in Application Examples 1 to 4 and Comparative Examples 1 to 5 are shown in Table 1.

[0075] Table 1 Transparency and shrinkage of the pipes obtained in Application Examples 1 to 4 and Comparative Examples 1 to 5

[0076]

[0077] Comparative Application Example 6

[0078] The PERT resin material is fed through a feeder and placed in an extruder to extrude a tube billet. The barrel temperature of the extruder is 180-200°C and the mold temperature is 190-210°C. The billet is shaped by vacuum adsorption, cooled in a water tank, and then pulled and cut.

[0079] Table 2 Test results of pipes obtained from Application Example 1 and Comparative Application Example 6

[0080]

[0081] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A modified PERT, characterized in that: Calculated by mass, it includes the following components: Second PERT 87~94.3 copies; 0.5~2 parts of micro-crosslinked masterbatch; 5-10 parts of glass beads; 0.2~1 parts of silane coupling agent; The micro-crosslinked masterbatch comprises the following raw materials in parts by mass: First PERT 100 copies; 0.4~1 part of antioxidant; 0.05~0.08 parts of peroxide crosslinking agent; The crosslinking degree of the micro-crosslinked masterbatch is 1.5-2.5%.

2. The modified PERT according to claim 1, characterized in that The peroxide cross-linking agent includes one or more of acyl peroxides, hydroperoxides, dialkyl peroxides, ester peroxides and ketone peroxides.

3. The modified PERT according to claim 1, characterized in that The peroxide crosslinking agent includes dicarbonate peroxide.

4. The modified PERT according to claim 1 or 2, characterized in that The antioxidant includes one or more of antioxidant 1010 , antioxidant 1076 and antioxidant 168 .

5. The modified PERT according to claim 4, characterized in that When the antioxidant includes antioxidant 1010, antioxidant 1076 and antioxidant 168, the mass ratio of antioxidant 1010, antioxidant 1076 and antioxidant 168 is (3.5~4.5):(1.5~2.5):(0.5~1.5).

6. The modified PERT according to claim 1, characterized in that The particle size of the micro-crosslinked masterbatch is 5-50 μm.

7. The modified PERT according to claim 1, characterized in that The preparation method of the micro-crosslinked masterbatch comprises the following steps: Mixing raw materials for preparing micro-crosslinked masterbatch, extruding, crosslinking and granulating to obtain the micro-crosslinked masterbatch; The cross-linking temperature is 300-350° C., and the cross-linking time is 0.75-1.2 min.

8. The modified PERT according to claim 1, characterized in that The glass microspheres are hollow glass microspheres with a particle size of 30-100 μm and a density of 0.1-0.7 g / cm 3 .

9. The modified PERT according to claim 1, characterized in that The models of the silane coupling agent include one or more of Japan Shin-Etsu KBE-846, American Dow Corning Z-6940, Chenguang New Materials KH-550, Chenguang New Materials KH-560 and Chenguang New Materials KH-570.

10. Use of the modified PERT according to any one of claims 1 to 9 in the preparation of floor heating pipes.

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