Polyolefin elastomer and method for preparing the same, hot melt adhesive and application thereof

Abstract

The application discloses a kind of polyolefin elastomer and its preparation method, hot melt adhesive and its application, it is related to hot melt adhesive technical field, solve the problem that existing technology is difficult to give consideration to hot melt adhesive bonding and processing anti-aging property.The raw material of polyolefin elastomer of the present application includes ethylene and the alpha-olefin of carbon atom number 3~8, ethylene is 35~75% of the mass of the alpha-olefin in the raw material;The melt index of the polyolefin elastomer 190 DEG C, 2.16kg is 100-1500g / 10min, in the temperature range of-70~40 DEG C, loss factor peak value 0.2~0.5.The hot melt adhesive using the polyolefin elastomer of the application has good bonding and anti-aging property simultaneously.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hot melt adhesive, in particular to a polyolefin elastomer, a preparation method thereof, a hot melt adhesive and application thereof. BACKGROUND

[0002] The polyolefin elastomer is a random copolymer of ethylene and alpha-olefin, the alpha-olefin is randomly inserted into the ethylene methylene segment structure, the regularity of the polymer chain is destroyed, the crystallinity of the polymer is reduced, and the corresponding viscoelasticity is significantly improved. Different polymer molecular weight indexes can meet the regulation and control requirements of product melt index and viscosity index, and the flexible controllability of viscosity and elasticity performance creates a natural advantage for its application in hot melt adhesive base resin. At the same time, the polymer chain of the polyolefin elastomer is mainly composed of saturated carbon hydrogen structure, has few unsaturated double bonds and does not contain polar components, and has excellent weather resistance and environmental protection. Therefore, it can be used as a hot melt adhesive base resin additive ingredient, mixed with tackifiers, plasticizers, waxes and other components, and widely applied to woodworking glue, sanitary material glue and packaging glue and other hot melt adhesive application fields.

[0003] As a hot melt adhesive base resin, the polyolefin elastomer needs to be mixed with other additives at a high temperature during the glue preparation process. After the glue is formed, it is solid at room temperature, and needs to be heated to a molten state during the application process of wood, paper or packaging material bonding, and then cooled and solidified on the adherend to form an adhesive layer. The anti-aging and bonding performance of the base resin during high-temperature processing and glue application is very critical to the mechanical properties of the hot melt adhesive in different temperature and application scenarios. Obviously, a high molecular weight low melt index base resin can improve the bonding performance of the glue, but it will also increase the viscosity of the glue. High viscosity resin not only has an adverse effect on flowability and processability, but also causes shear thickening during the glue preparation process, resulting in serious aging yellowing and gel problems.

[0004] Therefore, it is a key problem in the application of hot melt adhesive to provide a polyolefin elastomer base resin which has good anti-aging performance during the processing while maintaining good bonding performance of the glue. SUMMARY

[0005] The present application provides a polyolefin elastomer, a preparation method thereof, a hot melt adhesive and application thereof, to solve the problem that the bonding and processing anti-aging of the hot melt adhesive are difficult to be considered in the prior art.

[0006] In a first aspect, the present application provides a polyolefin elastomer, raw materials of which include ethylene and alpha-olefin with 3-8 carbon atoms, and the ethylene accounts for 35-75% of the mass of the alpha-olefin.

[0007] The polyolefin elastomer has a melt index of 100-1500 g / 10 min at 190 ℃ and 2.16 kg, and a loss factor peak value of 0.2-0.5 in the temperature range of -70-40 ℃.

[0008] In a possible implementation, the alpha-olefin includes one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene.

[0009] In a possible implementation, the polyolefin elastomer has a density of 0.860-0.910 g / cm 3 .

[0010] In a possible implementation, the polyolefin elastomer has a density of 0.860-0.910 g / cm 3 .

[0011] The mass ratio of the hydrogen to the ethylene is 10 -5 ~10 -3 .

[0012] The polymeric reaction has a temperature of 120-220 ℃, a pressure of 3-10 MPa, and a reaction time of 2-30 min.

[0013] The polymeric reaction obtains a random copolymer.

[0014] In a possible implementation, the dispersant includes a C6-C10 aliphatic hydrocarbon.

[0015] Optionally, the dispersant includes one or more of C6, C7, C8, C9, and C10 isomeric alkanes.

[0016] In a possible implementation, the feeding mass of the dispersant is 75%-230% of the sum of the feeding mass of the ethylene and the alpha-olefin. Here, the feeding amount of the dispersant refers to the amount when mixed with the ethylene and the alpha-olefin.

[0017] In a possible implementation, the terminating agent includes a lubricant and water; the terminating agent can terminate the catalyst and improve flowability.

[0018] In a possible implementation, the mass content of the lubricant in the terminating agent is ≥90%.

[0019] In a possible implementation, the lubricant includes one or more of silicone oil, calcium stearate, and zinc stearate.

[0020] In a possible implementation, the terminating agent comprises one or more of silicone oil emulsion, calcium stearate emulsion, zinc stearate emulsion, preferably silicone oil emulsion.

[0021] In a possible implementation, the ratio of the feed mass of the terminating agent to the feed mass of ethylene is 0.05% to 0.2%.

[0022] In a possible implementation, the method further comprises adding a deactivating agent to the reactor;

[0023] Optionally, the deactivating agent comprises one or more of alkyl aluminum, methyl aluminoxane, modified methyl aluminoxane, preferably triisobutyl aluminum.

[0024] Optionally, the feed mass of the deactivating agent is 10 to 135 ppm of the sum of the feed mass of ethylene and α-olefin.

[0025] The deactivating agent is used to remove water and oxygen impurities in the raw material to ensure the activity of the catalyst; the dispersing agent is used to dissolve the polymerization product to play a dispersing role.

[0026] In a possible implementation, in the step of adding ethylene, α-olefin, hydrogen, catalyst, co-catalyst, and dispersing agent to the reactor, the ethylene, α-olefin, hydrogen, and dispersing agent are mixed to obtain a mixed solution, and the mixed solution is adjusted to -100 to 0°C before being fed into the reactor.

[0027] In a possible implementation, the catalyst comprises a group ⅣB-ⅡB transition metal compound.

[0028] Optionally, the catalyst comprises one or more of bis (tetramethylcyclopentadienyl) hafnium dichloride, rac-ethylene-bis (indenyl) hafnium dichloride, dimethylsilyl (tert-butylamido) (tetramethylcyclopentadienyl) titanium dimethyl, dimethylsilyl (tert-butylamido) (4-pyrrolo-indenyl) titanium dimethyl, dimethylsilyl (tert-butylamido) (3,6-di-tert-butylfluorenyl) titanium dimethyl, [(7-methyl-tetrahydroquinolin-8-yl) tetramethylcyclopentadienyl-N] titanium dimethyl, diphenylmethylenyl (cyclopentadienyl) (fluorenyl) zirconium dichloride, di-p-tolyl (cyclopentadienyl) (2,6-di-tert-butylfluorenyl) zirconium dichloride, diphenylmethylenyl (cyclopentadienyl) (octamethyl octahydrofluorenyl) zirconium dichloride, diphenylmethylenyl (3-tert-butyl-2-methylcyclopentadienyl) (fluorenyl) zirconium dichloride.

[0029] In a possible implementation, the co-catalyst comprises one or more of tri-pentafluorophenyl borane, triphenylcarbenium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis (pentafluorophenyl) borate.

[0030] In a possible implementation, the feed mass of the catalyst is 0.4-3.5 ppm of the sum of the feed mass of ethylene and alpha-olefin.

[0031] In a possible implementation, the feed mass of the cocatalyst is 0.5-10 ppm of the sum of the feed mass of ethylene and alpha-olefin.

[0032] In a possible implementation, ethylene, hydrogen, alpha-olefin, impurity removing agent and dispersant are fed into a mixer, a low-temperature cooler and a polymerization reactor in a certain proportion, the catalyst and the cocatalyst are continuously fed into the polymerization reactor in a certain proportion respectively, the polymer solution obtained at the outlet of the polymerization reactor is mixed with a terminating agent through a static mixer, and then separated through high-temperature preheating and pressure reduction flash evaporation, the unreacted ethylene, hydrogen, alpha-olefin and dispersant light components are recycled, and the polymer melt heavy components are extruded and granulated to obtain polymer particles.

[0033] The low-temperature cooler has a temperature of -100-0 DEG C and a pressure of 3-10 MPa; the polymerization reaction is an exothermic reaction, and the raw materials are cooled before the polymerization reaction, so that the reaction temperature can be easily controlled at a target level.

[0034] In a third aspect, the application provides a hot melt adhesive, which comprises, in mass parts, 20-50 parts of tackifier, 10-20 parts of wax, 0-10 parts of plasticizer, 30-60 parts of the polyolefin elastomer or the polyolefin elastomer prepared according to the preparation method.

[0035] In a fourth aspect, the application provides application of the hot melt adhesive in woodworking glue, sanitary material glue or packaging glue.

[0036] The technical scheme of the application has the following advantages:

[0037] 1. The polyolefin elastomer provided by the application is prepared from raw materials including ethylene and alpha-olefin with a carbon atom number of 3-8, and the ethylene accounts for 35-75% of the mass of the alpha-olefin; the melt index of the polyolefin elastomer at 190 DEG C and under a load of 2.16 kg is 100-1500 g / 10 min, and the peak value of the loss factor is 0.2-0.5 in the temperature range of -70 DEG C to 40 DEG C.

[0038] The polyolefin elastomer has a high melt index and a suitable loss factor, and when applied to hot melt adhesive as a base resin, has good anti-aging performance after processing, low gel content and strong tack holding force, can improve the anti-aging of hot melt adhesive while maintaining good bonding performance. In the temperature range of-70~40℃, the peak value of the loss factor is 0.2~0.5, and the balance between viscosity and elasticity can be maintained in a wide temperature range. It can not only avoid the problem of insufficient elasticity and adhesion caused by too high viscosity and too high loss factor, but also reduce the influence of high elasticity and strength performance of low loss factor products in the hot melt adhesive stirring process, avoid the generation of heat aging and gel in the high temperature shearing process.

[0039] 2. The preparation method of the polyolefin elastomer comprises: adding ethylene, an alpha-olefin, hydrogen, a catalyst, a cocatalyst and a dispersant into a reactor to carry out a polymerization reaction to obtain the polyolefin elastomer; the mass ratio of the hydrogen to the ethylene is 10 -5 ~10 -3 ; the polymerization reaction is carried out at a temperature of 120~220℃, a pressure of 3~10MPa and for 2~30min.

[0040] The polymerization temperature and hydrogen adjustment are key process conditions for adjusting the melt index of the product. Low hydrogen consumption causes the melt index of the product to be low, and a high polymerization reaction temperature is needed to improve the melt index, which affects the reaction stability and causes aging and gel problems in the high temperature stirring process. High hydrogen consumption causes the melt index of the product to be too high, which affects the bonding performance of the hot melt adhesive product. In the present application, under the conditions of a specific monomer dosage ratio, a specific hydrogen dosage and a polymerization reaction condition, a polyolefin elastomer with a melt index of 100-1500g / 10min (2.16kg, 190℃) and a peak value of the loss factor of 0.2~0.5 in the temperature range of-70~40℃ is obtained. When the polyolefin elastomer prepared by the present application is applied to the field of hot melt adhesive as a base resin, the anti-aging of the hot melt adhesive can be improved while maintaining good bonding performance. DETAILED DESCRIPTION

[0041] The following examples are provided to better further understand the present application, but the following examples do not constitute limitations on the content and protection scope of the present application, and any product identical or similar to the present application obtained by the inspiration of the present application or by combining the present application with other prior art features falls within the protection scope of the present application.

[0042] If the specific experimental steps or conditions are not specified in the examples, they are operated according to the conventional experimental steps or conditions in the art. If the reagents or instruments used are not specified by the manufacturer, they are conventional reagent products or instruments that can be obtained by market purchase.

[0043] Source of raw materials

[0044]

[0045] The present application provides a preparation method of polyolefin elastomer, continuous solution polymerization is carried out in a high-pressure stirring reaction kettle with PLC control (i.e. the reactor hereinafter), comprising:

[0046] After the dispersant, ethylene, hydrogen, alpha-olefin and impurity remover after dehydration and deoxidization purification treatment are fully mixed, they are continuously fed into a 2.0 liter reactor equipped with a jacket for temperature control and an internal thermocouple. The ethylene and hydrogen feed amount is metered by a gas mass flow controller, and the dispersant, alpha-olefin and impurity remover are controlled by a diaphragm metering pump. Before entering the reactor, a low-temperature cooler controls the temperature of the mixed solution of dispersant, ethylene, alpha-olefin and impurity remover, which enters the bottom of the reactor in the temperature range of -100~0℃. The catalyst and co-catalyst are respectively configured into a solution with a concentration of 1wt%, and are synchronously fed into the bottom of the reactor by a diaphragm metering pump. The polymerization reaction is carried out in the reactor, and the polymerization reaction temperature is 120~220℃, the pressure is 3~10MPa, and the reaction time is 2~30min. The polymerization reaction temperature is stably controlled by the feed temperature and the jacket temperature of the reactor. The reactor is full-liquid operated at a stirring speed of 500-1000rpm, and the reaction liquid flows out through the outlet pipeline at the top of the reactor, mixes with the terminator through a static mixer, and then enters the heat exchanger to be heated to 260℃. The reactor pressure (3-10MPa) is controlled by the outlet pressure regulating valve of the heat exchanger. After the high-temperature reaction liquid is depressurized by the pressure control valve, it is sequentially introduced into the low-pressure flash system, and the small amount of ethylene, hydrogen, alpha-olefin and solvent removed are reused. The polymer melt is extruded and granulated to obtain polyolefin elastomer particles.

[0047] The detailed raw materials and polymerization reaction conditions of each example and comparative example are shown in Table 1 and Table 2.

[0048] Table 1 Continuous polymerization reaction conditions of each example

[0049]

[0050] Table 2 Continuous polymerization reaction conditions of each comparative example

[0051]

[0052] Test example

[0053] (1) The loss factor of the polyolefin elastomer is tested by a dynamic mechanical analyzer. The polymer is made into a film sample with a length of 30 mm, a width of 5 mm, and a thickness of 1 mm, ensuring that the sample is uniform, defect-free, and bubble-free. The shear mode is selected, and the instrument start temperature and end temperature are set to -90°C and 70°C, respectively, with a heating rate of 5°C / min and a frequency of 1 Hz. The sample is installed between the clamps, and the strain response of the sample is tested under alternating shear force.

[0054] (2) The melt index (MFR) of the polyolefin elastomer is tested by a melt index tester (MI-4) under the test conditions of 190°C and 2.16 kg load. The weight of the molten polymer extruded through a die with a length of 8 mm and an inner diameter of 2.095 mm within a specified time is the MFR, with the unit being g / 10 min.

[0055] (3) The density of the polyolefin elastomer is tested by a densimeter (immersion method METTLER). The mass of the sample suspended by a wire with a diameter not greater than 0.5 mm is weighed in air. The sample mass is not greater than 10 g, accurate to 0.1 mg, and the mass of the sample is recorded. The sample suspended by a fine wire is immersed in a beaker filled with immersion liquid placed on a fixed support. The temperature of the immersion liquid should be 23°C ± 2°C. The fine wire is used to remove the bubbles adhering to the sample. The mass of the sample in the immersion liquid is weighed to 0.1 mg.

[0056] (4) Gel content: a certain mass M1 of the polyolefin elastomer sample is placed in a metal filter ball, weighed to obtain mass M2, then the filter ball is immersed in a xylene solvent, heated to 150°C high temperature and dissolved for 5 hours, then the metal filter ball is taken out and weighed to obtain mass M3. The insoluble mass ratio is calculated according to formula 1-(M2-M3) / M1, which is the gel content.

[0057] (5) The polyolefin elastomer prepared by each example and comparative example is used to prepare a hot melt adhesive: under the protection of nitrogen atmosphere at 170°C high temperature, the polyolefin elastomer, tackifier (C5 resin), wax (polyethylene wax), and plasticizer (dibutyl phthalate) are melt blended in a heated container with stirring at a mass ratio of 50, 30, 15, and 5, respectively. After mixing uniformly, the hot melt adhesive is obtained by cooling and molding.

[0058] The holding adhesion time test uses a metal plate substrate to sandwich the hot melt adhesive sample, with a bonding area of 25 mm x 25 mm, a 500 g weight is hung, and the temperature is raised to 85°C. The time when the weight falls off is recorded.

[0059] The test results are shown in Table 3.

[0060] Table 3: Polyolefin elastomer index and hot melt adhesive application performance index

[0061]

[0062] As shown in Table 3, the polyolefin elastomer has a gel content of ≤0.60% and a holding adhesion time of ≥120 min, which indicates that the polyolefin elastomer has a low gel content and good anti-aging performance, and a high holding adhesion time, which indicates that the polyolefin elastomer has good adhesion performance. The polyolefin elastomer has both a low gel content and a high holding adhesion time, which indicates that the polyolefin elastomer has both good adhesion performance and anti-aging performance.

[0063] The polyolefin elastomer prepared by the method has improved oxidation resistance and adhesion performance, and has excellent performance of low gel content and strong holding adhesion in the field of hot melt adhesive applications.

[0064] Obviously, the above examples are only examples for clearly illustrating but not limiting the embodiments. Based on the above description, other different forms of changes or variations can be made by those skilled in the art. All the embodiments do not need to be exhausted here. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A polyolefin elastomer characterized by, The raw material includes ethylene and α-olefin with carbon number 3-8, and the ethylene accounts for 35-75% of the mass of the α-olefin; The polyolefin elastomer has a melt index of 100-1500 g / 10 min at 190 ℃ and 2.16 kg, and a loss factor peak value of 0.2-0.5 in the temperature range of-70-40 ℃.

2. The polyolefin elastomer of claim 1, wherein The α-olefin includes one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, and 1-octene. and / or the polyolefin elastomer has a density of 0.860 to 0.910 g / cm3 3 .

3. A process for the preparation of a polyolefin elastomer as claimed in claim 1 or 2, characterized in that, The method comprises the following steps: The ethylene, α-olefin, hydrogen, catalyst, co-catalyst, and dispersant are added into the reactor to perform a polymerization reaction for 2-30 min, and then the reaction is terminated by a terminating agent to obtain the polyolefin elastomer. The mass ratio of the hydrogen gas to the ethylene is 10 -5 ~10 -3 ; The polymerization reaction is performed at a temperature of 120-220 ℃ and a pressure of 3-10 MPa.

4. The process for the preparation of a polyolefin elastomer according to claim 3, characterized in that, At least one of the following conditions is met: (1) The dispersant includes C6-C10 aliphatic hydrocarbon; (2) The feeding mass of the dispersant is 75%-230% of the sum of the feeding mass of ethylene and α-olefin; (3) The terminating agent includes a lubricant and water; (4) The ratio of the feeding mass of the terminating agent to the feeding mass of ethylene is 0.05%-0.2%; (5) The preparation method further comprises adding a decontaminant into the reactor.

5. The process for the preparation of a polyolefin elastomer according to claim 4, characterized in that, At least one of the following conditions is met: (1) The dispersant includes one or more of C6, C7, C8, C9, and C10 isomeric alkanes; (2) In the terminating agent, the mass content of the lubricant is ≥90%; (3) The lubricant includes one or more of silicone oil, calcium stearate, and zinc stearate; (4) The terminating agent includes one or more of silicone oil emulsion, calcium stearate emulsion, and zinc stearate emulsion; (5) The decontaminant includes one or more of alkyl aluminum, methylaluminoxane, and modified methylaluminoxane; (6) The feeding mass of the decontaminant is 10-135 ppm of the sum of the feeding mass of ethylene and α-olefin.

6. The process for the preparation of a polyolefin elastomer according to claim 3, characterized in that, In the step of adding the ethylene, α-olefin, hydrogen, catalyst, co-catalyst, and dispersant into the reactor, the ethylene, α-olefin, hydrogen, and dispersant are mixed to obtain a mixed solution, and the mixed solution is adjusted to-100-0 ℃ before being sent into the reactor.

7. The process for the preparation of a polyolefin elastomer according to any one of claims 4-6, characterized in that, At least one of the following conditions is met: (1) The catalyst includes a group ⅣB-group ⅡB transition metal compound; (2) The co-catalyst includes one or more of tri(pentafluorophenyl)borane, triphenylcarbenium tetrakis(pentafluorophenyl)borate, and N,N-dimethylanilinium tetrakis(pentafluorophenyl)borate; (3) The feeding mass of the catalyst is 0.4-3.5 ppm of the sum of the feeding mass of ethylene and α-olefin; (4) The feeding mass of the co-catalyst is 0.5-10 ppm of the sum of the feeding mass of ethylene and α-olefin.

8. The process for the preparation of a polyolefin elastomer according to claim 7, characterized in that, The catalyst includes one or more of bis(tetramethylcyclopentadienyl)hafnium dichloride, rac-ethylene-bis(indenyl)hafnium dichloride, dimethylsilyl(t-butylamido)(tetramethylcyclopentadienyl) titanium dimethyl, dimethylsilyl(t-butylamido)(4-pyrrolyl-indenyl) titanium dimethyl, dimethylsilyl(t-butylamido)(3,6-di-t-butylfluorenyl) titanium dimethyl, [(7-methyl-tetrahydroquinolin-8-yl)tetramethylcyclopentadienyl-N] titanium dimethyl, diphenylmethlyene(cyclopentadienyl)(fluorenyl) zirconium dichloride, di-p-tolyl(cyclopentadienyl)(2,6-di-t-butylfluorenyl) zirconium dichloride, diphenylmethlyene(cyclopentadienyl)(octamethyl octahydrofluorenyl) zirconium dichloride, diphenylmethlyene(3-t-butyl-2-methylcyclopentadienyl)(fluorenyl) zirconium dichloride.

9. A hot melt adhesive characterized in that, comprises, by mass parts: tackifier 20-50 parts, wax 10-20 parts, plasticizer 0-10 parts, polyolefin elastomer according to any one of claims 1-2 or prepared according to any one of claims 3-8 30-60 parts.

10. Use of the hot-melt adhesive according to claim 9 in woodworking glue, sanitary material glue or packaging glue.

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