Micro-crosslinking master batch and preparation method thereof, modified PERT and application thereof

Abstract

The invention provides a micro-crosslinking master batch, a preparation method thereof, modified PERT and application thereof, and belongs to the field of pipe manufacturing. The invention provides a micro-crosslinked master batch, which is prepared from the following preparation raw materials in parts by mass: 100 parts of first PERT (Polyethylene Terephthalate); 0.4 to 1 part of an antioxidant; 0.02 to 0.18 part of a peroxide cross-linking agent; the crosslinking degree of the micro-crosslinking master batch is 1.5 to 2.5 percent. Free radicals generated by the peroxide cross-linking agent can make PERT become active PE macromolecular free radicals, and a net structure is formed. Molecular movement of the pipe in the cooling process becomes difficult due to the net-shaped structure, and therefore the shrinkage rate is reduced; the micro-crosslinked master batch is partially crosslinked by controlling the crosslinking degree, and the compatibility of the first PERT which is not crosslinked and the second PERT can be improved, so that the crosslinked PERT is uniformly dispersed in the second PERT, and the shrinkage rate is further reduced.

Description

Technical Field

[0001] The 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. As a non-cross-linked polyethylene material, PE-RT not only retains the low-temperature resistance of PE pipes, but also improves its creep resistance and strength at high temperatures. In recent years, it has gradually become an emerging material for the preparation of floor heating pipes. However, floor heating pipes made of PERT have the problem of dimensional shrinkage after they are off the production line. Summary of the invention

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

[0004] The present invention provides a micro-crosslinked masterbatch, which comprises the following preparation raw materials in parts by mass:

[0005]

[0006] Preferably, the peroxide crosslinking agent comprises 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] The raw materials for preparing the micro-crosslinked masterbatch are mixed, extruded, crosslinked and granulated 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 min.

[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, the particle size of the glass microspheres is 30 to 100 μm, and the density is 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, US 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 the polyethylene macromolecular chain, seize the hydrogen atoms on the molecular chain, and turn it into an active PE macromolecular free radical. When the PE macromolecular free radicals meet, they combine with each other to produce carbon-carbon crosslinking and form a network structure. The formed network structure makes it difficult for the molecules of the pipe to move during the cooling process, thereby reducing the shrinkage rate; in addition, the present invention controls the crosslinking degree to make the micro-crosslinked masterbatch partially crosslinked, and the first PERT that has not been crosslinked can improve the compatibility with the second PERT, thereby making the crosslinked PERT evenly dispersed in the second PERT, further reducing the shrinkage rate.

[0020] Since spherical objects are isotropic, glass beads can overcome the drawback of inconsistent shrinkage rates in different parts caused by orientation and reduce shrinkage rates; glass beads themselves have an extremely high refractive index, which can reflect visible light from the light source and enhance the transmission of light, thereby increasing the brightness and transparency of the pipe. Low-shrinkage and high-transparency PERT floor heating pipes give the pipes good stability: First, the actual number of meters produced can be accurately controlled during the production process, which can prevent deliberate lengthening of production due to shrinkage and save costs; second, the length of the product can be guaranteed not to shrink and the outer diameter will not decrease during storage, maintaining the appearance and quality of the product; third, the change in medium temperature during use will not cause stress shrinkage of the pipe, which will cause the connection to fall off and affect the safety of use. DETAILED DESCRIPTION

[0021] The present invention provides a micro-crosslinked masterbatch, which comprises the following preparation raw materials in parts by mass:

[0022]

[0023] In terms of mass fractions, the raw materials for preparing the micro-crosslinked masterbatch of the present invention include 100 parts of the 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 time is preferably 10 min; the mixing is preferably carried out under stirring, 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, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17 or 0.18 parts; the peroxide crosslinking agent preferably includes: acyl peroxide, hydroperoxide, dialkyl peroxide The invention relates to one or more of ester peroxides, ketone peroxides and dicarbonate peroxides; the acyl peroxide preferably comprises benzoyl peroxide and / or lauroyl peroxide; the hydroperoxide preferably comprises cumene hydroperoxide and / or tert-butyl hydroperoxide; the dialkyl peroxide preferably comprises di-tert-butyl peroxide and / or diisopropyl peroxide; the ester peroxide preferably comprises tert-butyl perbenzoate and / or tert-butyl pervalerate; the ketone peroxide preferably comprises methyl ethyl ketone peroxide and / or cyclohexanone peroxide; the dicarbonate peroxide preferably comprises 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] The raw materials for preparing the micro-crosslinked masterbatch are mixed, extruded, crosslinked and granulated 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 plastic high-speed mixer, and the rotation speed of the plastic high-speed mixer is preferably 800 r / min.

[0032] In the present invention, the extrusion is preferably carried out in a screw extruder; the rotation speed of the screw in the screw extruder is preferably 40-50r / 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℃±5℃, the temperature of the second temperature zone is preferably 145℃±5℃, the temperature of the third temperature zone is preferably 135℃±5℃, and the temperature of the fourth temperature zone is preferably 130℃±5℃; the extrusion speed of the screw extruder is preferably 5-8m / 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 weight percentage, 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 weight percentage 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 Maanshan 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 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 raw materials of modified PERT are mixed and then extruded, vacuum-adsorbed and shaped, cooled, pulled 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 in conjunction with the embodiments, but they should not be understood as limiting the scope of protection of the present invention.

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

[0046] Example 1

[0047] Preparation of compound antioxidant

[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, cold mixing time of 10 min and 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, with a rotation speed of 800 r / min, and stirred at high speed to obtain a premix.

[0051] The uniformly mixed premix is ​​extruded into strips through a single screw extruder, the screw speed is 50r / min, and the temperature of each section of the extruder is set as follows: Zone 4: 130℃±5, Zone 3: 135℃±5, Zone 2: 140℃±5, Zone 1: 145℃±5. The extruded strips are passed through a traction machine and a 6m long infrared cross-linking furnace at a speed of 8m / min. The temperature of the infrared cross-linking furnace is set to 300℃, and then cut into uniform particles by a cold cutter to obtain 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 micro-crosslinked masterbatch numbered as Example 1, 6.6 parts of high-performance hollow glass microspheres and 0.8 parts of silane coupling agent are mixed uniformly by a high-speed mixer, and the hot mixing temperature is 70-80° C. After uniform mixing, it is sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature is 175-200° C., mold body temperature is 190-215° C.), vacuum adsorption shaping, water tank cooling, pulling, cutting, and the pipe product is obtained.

[0058] Application Example 2

[0059] 90 parts of PERT resin, 1.1 parts of micro-crosslinked masterbatch numbered as Example 2, 8 parts of high-performance hollow glass microspheres and 0.9 parts of silane coupling agent are mixed uniformly by a high-speed mixer, and the hot mixing temperature is 70-80° C. After uniform mixing, it is sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature is 175-200° C., mold body temperature is 190-215° C.), vacuum adsorption shaping, water tank cooling, pulling, cutting, and the pipe product is obtained.

[0060] Application Example 3

[0061] 88 parts of PERT resin, 1.8 parts of micro-crosslinked masterbatch numbered as Example 3, 9.2 parts of high-performance hollow glass microspheres and 1 part of silane coupling agent are mixed uniformly by a high-speed mixer, and the hot mixing temperature is 70-80° C. After uniform mixing, it is sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature is 175-200° C., mold body temperature is 190-215° C.), vacuum adsorption shaping, water tank cooling, pulling, cutting, and the pipe product is obtained.

[0062] Application Example 4

[0063] 88 parts of PERT resin, 2 parts of micro-crosslinked masterbatch numbered as Example 4, 9 parts of high-performance hollow glass microspheres and 1 part of silane coupling agent are mixed uniformly by a high-speed mixer, and the hot mixing temperature is 70-80° C. After uniform mixing, they are sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature is 175-200° C., mold body temperature is 190-215° C.), vacuum adsorption shaping, water tank cooling, pulling, cutting, and the pipe product is obtained.

[0064] Comparative application example 1

[0065] 91.5 parts of PERT resin, 1 part of micro-crosslinked masterbatch numbered as comparative example 1, 7 parts of high-performance hollow glass microspheres and 0.5 parts of silane coupling agent are mixed evenly by a high-speed mixer, and the hot mixing temperature is 70-80°C. After being mixed evenly, they are sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature is 175-200°C, mold body temperature is 190-215°C), and after vacuum adsorption shaping, water tank cooling, pulling and cutting, the pipe product is obtained.

[0066] Comparative Application Example 2

[0067] 92.8 parts of PERT resin, 0.7 parts of micro-crosslinked masterbatch numbered as comparative example 2, 6 parts of high-performance hollow glass microspheres and 0.5 parts of silane coupling agent are mixed uniformly by a high-speed mixer, and the hot mixing temperature is 70-80°C. After uniform mixing, the mixture is sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature is 175-200°C, mold body temperature is 190-215°C), and after vacuum adsorption shaping, water tank cooling, pulling and cutting, the pipe product is obtained.

[0068] Comparative Application Example 3

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

[0070] Comparative Application Example 4

[0071] 89.8 parts of PERT resin, 1.5 parts of micro-crosslinked masterbatch No. 4, 8 parts of high-performance hollow glass microspheres and 0.7 parts of silane coupling agent were mixed evenly by a high-speed mixer at a hot mixing temperature of 70-80° C. After mixing evenly, the mixture was sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature of 175-200° C., mold body temperature of 190-215° C.).

[0072] Comparative Application Example 5

[0073] 91 parts of PERT resin, 1.2 parts of micro-crosslinked masterbatch No. 5, 7 parts of high-performance hollow glass microspheres and 0.8 parts of silane coupling agent were mixed evenly by a high-speed mixer at a hot mixing temperature of 70-80° C. After mixing evenly, the mixture was sent to a single-screw production equipment through a feeder for extrusion molding (barrel temperature of 175-200° C., mold body 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 passed 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 material 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 principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A micro-crosslinked masterbatch, characterized in that: The micro-crosslinked masterbatch comprises the following raw materials in parts by mass: First PERT 100 copies; 0.4-1 part of antioxidant; Peroxide crosslinking agent 0.02-0.18 parts; The crosslinking degree of the micro-crosslinked masterbatch is 1.5-2.5%.

2. The micro-crosslinked masterbatch according to claim 1, characterized in that: The peroxide crosslinking agent includes one or more of acyl peroxides, hydroperoxides, dialkyl peroxides, ester peroxides, ketone peroxides and dicarbonate peroxides.

3. The micro-crosslinked masterbatch according to claim 1 or 2, characterized in that: The antioxidant includes one or more of antioxidant 1010 , antioxidant 1076 and antioxidant 168 .

4. The micro-crosslinked masterbatch according to claim 3, 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).

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

6. The method for preparing the micro-crosslinked masterbatch according to any one of claims 1 to 5, characterized in that: The following steps are involved: The raw materials for preparing the micro-crosslinked masterbatch are mixed, extruded, crosslinked and granulated 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.

7. A modified PERT, characterized in that: In parts by mass, it includes the following components: The micro-crosslinked masterbatch is the micro-crosslinked masterbatch according to any one of claims 1 to 5 or the micro-crosslinked masterbatch prepared by the preparation method according to claim 6.

8. The modified PERT according to claim 7, characterized in that 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 .

9. The modified PERT according to claim 7, 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 Material KH-550, Chenguang New Material KH-560 and Chenguang New Material KH-570.

10. Use of the modified PERT according to any one of claims 7 to 9 in the preparation of floor heating pipes.

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