Hot melt adhesive for polybutene, its preparation method and barrier sheet

Abstract

This invention relates to the field of hot melt adhesive technology, and in particular to a hot melt adhesive for polybutene, its preparation method, and a barrier sheet. The hot melt adhesive for polybutene comprises the following components by mass percentage: 10%–30% polybutene-1 grafted maleic anhydride, 50%–80% polybutene-1 matrix, 0%–20% elastomer, and 0.1%–1% antioxidant; wherein the grafting rate of maleic anhydride in the polybutene-1 grafted maleic anhydride is ≥0.5wt%; and the density of the polybutene-1 in the polybutene-1 grafted maleic anhydride and the density of the polybutene-1 matrix are ≥0.91 g / cm³. 3 The hot melt adhesive for polybutene of the present invention, by introducing polybutene-1 grafted with maleic anhydride, combined with polybutene-1 and optionally an elastomer, can significantly improve the adhesive strength and adhesion durability of the hot melt adhesive to polybutene-1 and EVOH, and is odorless and free of small molecule migration, and has good processability.

Description

TECHNICAL FIELD

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

[0002] Polybutene-1 (PB-1) is a thermoplastic resin polymerized from n-butene. Currently, there are two kinds of traditional hot melt adhesives for polybutene-1: one is a hot melt adhesive with polybutene-1 grafted epoxy group polar monomer (such as glycidyl methacrylate), polybutene-1, elastomer, acid anhydride curing agent as main components, which is simple to prepare and low in cost; but it is difficult to meet the market demand due to low bonding strength, strong odor, and high small molecule residue. The other is a hot melt adhesive prepared with polypropylene grafted maleic anhydride, elastomer, and polypropylene as main raw materials, which is simple to prepare and low in cost; but it is difficult to be generally recognized by the market due to poor aging resistance, poor compatibility with polybutene-1, and poor bonding durability. Therefore, it is of great significance to develop a hot melt adhesive for polybutene-1 with good bonding strength, environmental protection, and good aging resistance.

[0003] In view of this, the present application is proposed. SUMMARY

[0004] The purpose of the present application is to provide a hot melt adhesive for polybutene, a preparation method thereof and a barrier sheet. The hot melt adhesive of the present application introduces polybutene-1 grafted maleic anhydride, cooperates with polybutene-1 and optionally elastomer, which can not only improve the bonding strength and bonding durability of the hot melt adhesive to polybutene-1 and ethylene-vinyl alcohol copolymer (EVOH), but also has no odor and small molecule migration.

[0005] In order to achieve the above-mentioned purpose of the present application, the first aspect of the present application provides a hot melt adhesive for polybutene, comprising the following components by mass percentage: polybutene-1 grafted maleic anhydride 10% to 30%, polybutene-1 matrix 50% to 80%, elastomer 0% to 20%, and antioxidant 0.1% to 1%.

[0006] In the polybutene-1 grafted maleic anhydride, the grafting rate of maleic anhydride is ≥0.5wt%.

[0007] The density of polybutene-1 in the polybutene-1 grafted maleic anhydride and the polybutene-1 matrix is ≥0.91g / cm 3 .

[0008] In the specific embodiment of the present application, the melt index of polybutene-1 in the polybutene-1 grafted maleic anhydride and the polybutene-1 matrix under the condition of 190℃ / 2.16kg is ≤5g / 10min.

[0009] In the specific embodiment of the present application, the polybutene-1 grafted maleic anhydride is mainly prepared by reacting polybutene-1 95%~98.7%, maleic anhydride 1%~4% and initiator 0.3%~1% by mass percentage.

[0010] In the specific embodiment of the present application, the preparation of the polybutene-1 grafted maleic anhydride comprises: after mixing polybutene-1, maleic anhydride and initiator in proportion, melt extrusion is carried out; in the melt extrusion, vacuum treatment is carried out at the end of the extruder. Further, the length-diameter ratio of the twin-screw extruder used in the melt extrusion is ≥48:1.

[0011] In the specific embodiment of the present application, the elastomer comprises at least one of ethylene-based elastomer, propylene-based elastomer, ethylene-propylene rubber and butylene-based elastomer.

[0012] In the specific embodiment of the present application, the mass ratio of the polybutene-1 matrix to the elastomer is (5~15):1.

[0013] The second aspect of the present application provides a preparation method of the hot melt adhesive for polybutene provided by the first aspect of the present application, comprising the following steps: mixing polybutene-1 grafted maleic anhydride, polybutene-1 matrix, optionally elastomer and antioxidant in proportion, and carrying out melt extrusion granulation.

[0014] In the specific embodiment of the present application, in the melt extrusion granulation, the temperature is 70~200℃. Further, the temperature of each temperature is 80±5℃, 160±5℃, 190±5℃, 190±5℃, 190±5℃, 190±5℃, 190±5℃, 190±5℃ respectively.

[0015] The third aspect of the present application provides a barrier sheet, comprising polybutene-1 layer, hot melt adhesive layer and EVOH layer which are stacked in the thickness direction; the hot melt adhesive layer is prepared from the hot melt adhesive for polybutene provided by the first aspect of the present application.

[0016] In the specific embodiment of the present application, in the barrier sheet, the thickness of the hot melt adhesive layer is 5~50μm.

[0017] Compared with the prior art, the present application has the following beneficial effects:

[0018] (1) In the hot melt adhesive for polybutene of the present application, by introducing polybutene-1 grafted maleic anhydride, in combination with polybutene-1 and optionally elastomer, the bonding strength and bonding durability of the hot melt adhesive to polybutene-1 and EVOH can be significantly improved, and there is no odor and small molecule migration, and good processing performance is also achieved.

[0019] (2) The preparation method of the hot melt adhesive for polybutene of the present invention is simple to operate and highly environmentally friendly.

[0020] (3) The barrier sheet made by using the hot melt adhesive of the present invention has good bonding strength and bonding durability for both the polybutene-1 layer and the EVOH layer in the barrier sheet, so that the barrier sheet has durable barrier performance. At the same time, the barrier sheet has suitable stiffness to meet the application requirements of the underfloor heating pipe. Detailed Implementation

[0021] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. However, those skilled in the art will understand that the embodiments described below are some embodiments of the present invention, but not all embodiments, and are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall be followed. Where the manufacturers of reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0022] The first aspect of the present invention provides a hot melt adhesive for polybutene, comprising the following components by mass percentage: 10%–30% polybutene-1 grafted maleic anhydride, 50%–80% polybutene-1 matrix, 0%–20% elastomer, and 0.1%–1% antioxidant;

[0023] In polybutene-1 grafted with maleic anhydride, the grafting rate of maleic anhydride is ≥0.5 wt%.

[0024] The density of polybutene-1 grafted onto maleic anhydride and the polybutene-1 matrix is ​​≥0.91 g / cm³. 3 .

[0025] In this invention, the hot melt adhesive innovatively introduces polybutene-1 grafted with maleic anhydride as one of the core raw materials. Appropriate amounts and grafting rates of polybutene-1 grafted with maleic anhydride, along with the reaction of the maleic anhydride with EVOH, significantly improve the adhesive performance of the hot melt adhesive to EVOH. Simultaneously, by combining a polybutene-1 matrix and optionally an elastomer, the density of polybutene-1 is controlled to improve the adhesion, weather resistance, stiffness, and processability of barrier sheets using this hot melt adhesive.

[0026] In different embodiments, the amounts of each component in the hot melt adhesive for polybutene can be as follows, by mass percentage:

[0027] The amount of polybutene-1 grafted with maleic anhydride can be 10%, 12%, 15%, 18%, 20%, 22%, 25%, 28%, 30%, or any combination thereof. The inventors of this invention have found that when the amount of polybutene-1 grafted with maleic anhydride is too high, the overall fluidity of the hot melt adhesive is too high, which not only leads to poor uniformity of the hot melt adhesive layer structure but also to a decrease in adhesive strength. When the amount of polybutene-1 grafted with maleic anhydride is too low, the improvement in adhesive performance is not significant. By controlling the amount of polybutene-1 grafted with maleic anhydride in the hot melt adhesive of this invention within the above range, the adhesive performance, weather resistance, and strength of the hot melt adhesive can be effectively balanced.

[0028] The amount of polybutene-1 matrix can be 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, 70%, 72%, 75%, 78%, 80%, or any combination thereof;

[0029] The amount of elastomer can be 0%, 2%, 5%, 8%, 10%, 12%, 15%, 18%, 20%, or any combination thereof. Appropriate introduction of elastomer can work with the other components to improve the adhesion and weather resistance of hot melt adhesive. However, excessive introduction of elastomer will not only worsen the adhesion and weather resistance, but also lead to insufficient strength of hot melt adhesive, resulting in insufficient stiffness of the barrier sheet made from it.

[0030] The amount of antioxidant can be 0.1%, 0.3%, 0.5%, 0.8%, or any combination thereof.

[0031] In the hot melt adhesive of this invention, the maleic anhydride grafting rate of the polybutene-1 grafted maleic anhydride is ≥0.5wt%, such as 0.5wt% to 2wt%, or 0.5wt% to 1.5wt%, for example, it can be 0.5wt%, 0.8wt%, 1wt%, 1.2wt%, 1.5wt%, 1.8wt%, 2wt%, or any combination thereof. When the maleic anhydride grafting rate in the polybutene-1 grafted maleic anhydride is less than 0.5wt%, the hot melt adhesive has poor adhesion to EVOH; when the maleic anhydride grafting rate in the polybutene-1 grafted maleic anhydride is too high, such as higher than 2wt%, although the adhesion to the EVOH layer is improved, excessive maleic anhydride can easily cause the hot melt adhesive layer to react in high temperature, humid environment, etc., affecting the weather resistance of the hot melt adhesive layer. Therefore, by controlling the grafting rate of maleic anhydride in polybutene-1 grafted with maleic anhydride to ≥0.5wt%, such as 0.5wt%~2wt%, it is more helpful to improve the adhesion and weather resistance of hot melt adhesive.

[0032] The density of the polybutene-1 grafted maleic anhydride polybutene-1 and the polybutene-1 matrix used in the hot melt adhesive of this invention is ≥0.91 g / cm³. 3 For example, 0.91~0.93g / cm 3 For example, it could be 0.91 g / cm³. 3 0.915g / cm 3 0.92g / cm 3 0.925g / cm 3 0.93g / cm 3 Or a range consisting of any two of them. When the density of polybutene-1 used in the hot melt adhesive is less than 0.91 g / cm³. 3 When this happens, the hot melt adhesive becomes too soft, which not only affects its bonding performance but also reduces its temperature resistance.

[0033] The polybutene-1 used in this invention is all pipe-grade or extrusion-grade polybutene-1.

[0034] In specific embodiments of the present invention, the melt index of polybutene-1 grafted with maleic anhydride and the polybutene-1 matrix at 190°C / 2.16kg is ≤5g / 10min, for example, 0.1 to 5g / 10min. In different embodiments, the melt index of polybutene-1 grafted with maleic anhydride and the polybutene-1 matrix at 190°C / 2.16kg can be 5g / 10min, 4.5g / 10min, 4g / 10min, 3g / 10min, 2g / 10min, 1g / 10min, 0.5g / 10min, 0.1g / 10min, or any combination thereof.

[0035] In this process, the density of polybutene-1 grafted onto maleic anhydride and the melt index of the polybutene-1 matrix can be the same or different, provided that each satisfies the aforementioned conditions. Adjusting the melt index of both components to meet these conditions improves the extrusion molding capability of the hot melt adhesive. An excessively high melt index is detrimental to extrusion molding.

[0036] In a specific embodiment of the present invention, polybutene-1 grafted with maleic anhydride is mainly prepared by reacting 95% to 98.7% polybutene-1, 1% to 4% maleic anhydride and 0.3% to 1% initiator by mass percentage.

[0037] In different embodiments, taking the total amount of raw materials used to prepare polybutene-1 grafted maleic anhydride as 100%, the amount of polybutene-1 can be 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.7%, or any combination thereof; the amount of maleic anhydride can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or any combination thereof; and the amount of initiator can be 0.3%, 0.5%, 0.8%, 1%, or any combination thereof.

[0038] In a specific embodiment of the present invention, maleic anhydride is analytical grade maleic anhydride.

[0039] In a specific embodiment of the present invention, the initiator includes at least one selected from dicumyl peroxide, di-tert-butyl peroxide, benzoyl peroxide, dichlorobenzoyl peroxide, tert-butyl peroxylaurate, 2,5-dimethyl-2,5-di(tert-butylperoxide)hexane, bis(tert-butylperoxyisopropyl)benzene, tert-butylisopropylphenyl peroxide, tert-butyl peroxybenzoate, and tert-butyl peroxyacetate.

[0040] In a specific embodiment of the present invention, the preparation of polybutene-1 grafted with maleic anhydride includes: mixing polybutene-1, maleic anhydride, and an initiator in a certain proportion, followed by melt extrusion; during melt extrusion, a vacuum treatment is performed at the end of the extruder. Further, the twin-screw extruder used for melt extrusion has a length-to-diameter ratio ≥48:1. The end of the extruder is the last section of the extruder barrel.

[0041] The inventors of this invention discovered that, due to the inherent molecular structure of polybutene-1, existing methods for grafting maleic anhydride onto polybutene-1 result in low grafting rates and high residual maleic anhydride monomers, making it difficult to improve material adhesion while maintaining environmental friendliness. This invention, by employing a twin-screw extruder with a high aspect ratio and using end-stage vacuuming, not only improves the grafting rate of maleic anhydride in polybutene-1 but also significantly reduces residual maleic anhydride monomers. The aspect ratio of the twin-screw extruder can be 48:1, 52:1, etc. A 48:1 aspect ratio, combined with end-stage vacuuming, satisfies both high grafting rates and low monomer residues. During vacuuming, the vacuum level at the extruder end is maintained at -0.1 MPa or higher, for example, -0.1 MPa. Here, vacuum level refers to relative vacuum.

[0042] In a specific embodiment of the present invention, the melt extrusion temperature in the preparation of polybutene-1 grafted with maleic anhydride is 70–200°C. Further, the temperatures in each temperature zone are 80±5°C, 160±5°C, 190±5°C, 190±5°C, 190±5°C, 190±5°C, 190±5°C, and 190±5°C, respectively.

[0043] In a specific embodiment of the present invention, the elastomer includes at least one of vinyl elastomers, propylene elastomers, ethylene propylene rubber, and butene elastomers.

[0044] In a specific embodiment of the present invention, the antioxidant includes at least one of hindered phenolic antioxidants and phosphite antioxidants.

[0045] In a specific embodiment of the present invention, the mass ratio of polybutene-1 matrix to elastomer is (5-15):1, such as 5:1, 5.5:1, 6:1, 6.5:1, 7:1, 7.5:1, 8:1, 8.5:1, 9:1, 9.5:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, or any combination thereof. Based on the hot melt adhesive system of the present invention, further adjusting the mass ratio of polybutene-1 matrix to elastomer to meet the above range helps to balance the adhesive properties, adhesion durability, and stiffness of the barrier sheet made using this hot melt adhesive.

[0046] The second aspect of this invention provides a method for preparing the hot melt adhesive for polybutene provided in the first aspect of this invention, comprising the following steps: mixing polybutene-1 grafted maleic anhydride, polybutene-1 matrix, optionally an elastomer and an antioxidant in a certain proportion, and then performing melt extrusion granulation. The twin-screw extruder used for melt extrusion granulation has an aspect ratio ≥ 48:1.

[0047] In a specific embodiment of the present invention, the temperature in melt extrusion granulation is 70–200°C. Further, the temperatures of each temperature zone are 80±5°C, 160±5°C, 190±5°C, 190±5°C, 190±5°C, 190±5°C, 190±5°C, and 190±5°C, respectively.

[0048] A third aspect of the present invention provides a barrier sheet comprising a polybutene-1 layer, a hot melt adhesive layer, and an EVOH layer stacked along the thickness direction; the hot melt adhesive layer is made from the hot melt adhesive for polybutene provided in the first aspect of the present invention.

[0049] In a specific embodiment of the present invention, the thickness of the hot melt adhesive layer in the barrier sheet is 5 to 50 μm, such as 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm or any combination thereof.

[0050] In a specific embodiment of the present invention, the thickness of the polybutene-1 layer is 150 to 250 μm, such as 150 μm, 180 μm, 200 μm, 220 μm, 250 μm or any combination thereof; the thickness of the EVOH layer is 10 to 50 μm, such as 10 μm, 20 μm, 30 μm, 40 μm, 50 μm or any combination thereof.

[0051] The present invention also provides an optional method for preparing a barrier sheet, comprising the following steps: feeding the raw materials of the polybutene-1 layer, the hot melt adhesive layer and the EVOH layer into a casting machine for co-extrusion casting to obtain a barrier sheet.

[0052] In a specific embodiment of the present invention, in the co-extrusion casting process, the extrusion temperature of the polybutene-1 layer is 120–210°C, specifically, the extrusion temperatures of each zone are 130±5°C, 200±5°C, 200±5°C, and 200±5°C, respectively; the extrusion temperature of the hot melt adhesive layer is 170–240°C, specifically, the extrusion temperatures of each zone are 180±5°C, 230±5°C, 230±5°C, and 230±5°C, respectively; and the extrusion temperature of the EVOH layer is 120–210°C, specifically, the extrusion temperatures of each zone are 130±5°C, 200±5°C, 200±5°C, and 200±5°C, respectively.

[0053] Example 1

[0054] This embodiment provides a hot melt adhesive for polybutene, the raw materials of which include the following components by mass percentage: 20% polybutene-1 grafted maleic anhydride, 79.5% polybutene-1 matrix (Mitsui Chemicals P5250N, Japan) and 0.5% antioxidant B215.

[0055] In the polybutene-1 grafted maleic anhydride, the grafting rate of maleic anhydride is 1 wt%. The specific preparation method of polybutene-1 grafted maleic anhydride includes: weighing polybutene-1 (Mitsui Chemicals P5250N), maleic anhydride and dicumyl peroxide at mass percentages of 98.5%, 1.2% and 0.3% respectively, and mixing them evenly in a mixer; then feeding them into a twin-screw extruder with a length-to-diameter ratio of 48:1 through the feeding port for melt extrusion. The temperature settings are 80℃, 160℃, 190℃, 190℃, 190℃, 190℃, 190℃ and 190℃ respectively. A vacuum process is used in the last section of the extruder barrel to control the vacuum degree of the last section of the extruder barrel to be above -0.1MPa. Granulation and drying are then carried out for later use.

[0056] The preparation method of the hot melt adhesive for polybutene in this embodiment includes: weighing polybutene-1 grafted maleic anhydride, polybutene-1 matrix and antioxidant B215 in proportion, mixing them evenly, and then feeding them into a twin-screw extruder with an aspect ratio of 48:1 for melt extrusion. The temperature settings are 80℃, 160℃, 190℃, 190℃, 190℃, 190℃, 190℃, and 190℃ in sequence. The mixture is then granulated and dried to obtain hot melt adhesive granules.

[0057] Example 2

[0058] This embodiment provides a hot melt adhesive for polybutene, the raw materials of which include the following components by mass percentage: 20% polybutene-1 grafted maleic anhydride, 69.5% polybutene-1 matrix (Mitsui Chemicals P5250N, Japan), 10% ethylene propylene rubber elastomer (Dow EPDM 3722, USA) and 0.5% antioxidant B215.

[0059] In this case, the grafting rate of polybutene-1 grafted with maleic anhydride was 1 wt%, and the preparation method was the same as in Example 1.

[0060] The preparation method of hot melt adhesive for polybutene in this embodiment includes: weighing polybutene-1 grafted maleic anhydride, polybutene-1 matrix, ethylene propylene rubber elastomer and antioxidant B215 in proportion, mixing them evenly, and then feeding them into a twin-screw extruder with an aspect ratio of 48:1 for melt extrusion. The temperature settings are 80℃, 160℃, 190℃, 190℃, 190℃, 190℃, 190℃, and 190℃ in sequence. The mixture is then granulated and dried to obtain hot melt adhesive granules.

[0061] Example 3

[0062] This embodiment refers to the hot melt adhesive for polybutene and its preparation method in Example 2, the only difference being that an equal weight of polyolefin elastomer (LG Chem Korea, POE LC575) is used instead of the ethylene propylene rubber elastomer in Example 2.

[0063] Example 4

[0064] This embodiment refers to the hot melt adhesive for polybutene and its preparation method in Example 3, the only difference being the amount of polybutene-1 grafted with maleic anhydride and the amount of polybutene-1 matrix.

[0065] The hot melt adhesive for polybutene in this embodiment comprises the following components by mass percentage: 10% polybutene-1 grafted maleic anhydride, 79.5% polybutene-1 matrix (Mitsui Chemicals P5250N, Japan), 10% polyolefin elastomer (LG Chem, Korea, POE LC575), and 0.5% antioxidant B215.

[0066] Example 5

[0067] This embodiment refers to the hot melt adhesive for polybutene and its preparation method in Example 4, the only difference being that the grafting rate of maleic anhydride onto polybutene-1 is different.

[0068] In this embodiment, the grafting rate of maleic anhydride onto polybutene-1 is 2 wt%. The preparation method of polybutene-1 grafted with maleic anhydride in this embodiment is the same as that in Example 1, except that the proportions of polybutene-1 (Mitsui Chemicals P5250N), maleic anhydride, and dicumyl peroxide are different. In the preparation of polybutene-1 grafted with maleic anhydride in this embodiment, polybutene-1, maleic anhydride, and dicumyl peroxide are weighed out at mass percentages of 96.9%, 2.5%, and 0.6%, respectively.

[0069] Example 6 group

[0070] This example group refers to the hot melt adhesive for polybutene and its preparation method in Example 2, the only difference being the amount of polybutene-1 matrix and ethylene propylene rubber elastomer. The rest are the same as in Example 2, and the specific differences are as follows.

[0071] Example 6a: The amount of polybutene-1 matrix was 66.5%, and the amount of ethylene propylene rubber elastomer was 13%;

[0072] Example 6b: The amount of polybutene-1 matrix was 72%, and the amount of ethylene propylene rubber elastomer was 7.5%;

[0073] Example 6c: The amount of polybutene-1 matrix was 63.5%, and the amount of ethylene propylene rubber elastomer was 16%;

[0074] Example 6d: The amount of polybutene-1 matrix was 74.5%, and the amount of ethylene propylene rubber elastomer was 5%.

[0075] Comparative Example 1

[0076] Comparative Example 1 refers to the hot melt adhesive for polybutene and its preparation method in Example 1, the only difference being that the grafting rate of maleic anhydride onto polybutene-1 is different.

[0077] The grafting rate of maleic anhydride onto polybutene-1 in Comparative Example 1 was 0.4 wt%. The preparation method of polybutene-1 grafted with maleic anhydride in Comparative Example 1 was the same as that in Example 1, except that the proportions of polybutene-1 (Mitsui Chemicals P5250N), maleic anhydride, and dicumyl peroxide were different. In the preparation of polybutene-1 grafted with maleic anhydride in Comparative Example 1, polybutene-1, maleic anhydride, and dicumyl peroxide were weighed out at mass percentages of 99.2%, 0.5%, and 0.3%, respectively.

[0078] Comparative Example 2

[0079] Comparative Example 2 refers to the hot melt adhesive for polybutene and its preparation method in Example 2, the only difference being the amount of polybutene-1 matrix and ethylene propylene rubber elastomer used, the rest are the same as in Example 2.

[0080] The hot melt adhesive for polybutene in Comparative Example 2 contains the following components by mass percentage: 20% polybutene-1 grafted maleic anhydride, 49.5% polybutene-1 matrix (Mitsui Chemicals P5250N, Japan), 30% ethylene propylene rubber elastomer (Dow EPDM 3722, USA), and 0.5% antioxidant B215.

[0081] Comparative Example 3

[0082] Comparative Example 3 is the same as Example 3, except that the amount of maleic anhydride grafted onto polybutene-1 and the preparation method thereof are different.

[0083] The hot melt adhesive for polybutene in Comparative Example 3 contains the following components by mass percentage: 40% polybutene-1 grafted maleic anhydride, 49.5% polybutene-1 matrix (Mitsui Chemicals P5250N, Japan), 10% polyolefin elastomer (LG Chem, Korea, POE LC575), and 0.5% antioxidant B215.

[0084] Comparative Example 4

[0085] Comparative Example 4 refers to the hot melt adhesive for polybutene and its preparation method in Example 5, the only difference being that the amount of polybutene-1 grafted with maleic anhydride and the amount of polybutene-1 matrix are different, the rest are the same as in Example 5.

[0086] The hot melt adhesive for polybutene in Comparative Example 4 contains the following components by mass percentage: 1% polybutene-1 grafted maleic anhydride, 88.5% polybutene-1 matrix (Mitsui Chemicals P5250N, Japan), 10% polyolefin elastomer (LG Chem, Korea, POE LC575), and 0.5% antioxidant B215.

[0087] Comparative Example 5

[0088] Comparative Example 5 refers to the hot melt adhesive for polybutene and its preparation method in Example 5, the only difference being that the type of polybutene-1 matrix is ​​different, and all other aspects are the same as in Example 5.

[0089] The hot melt adhesive of Comparative Example 5 uses polybutene-1 (Ryander Basel 8310M) as its matrix in its raw materials, with a density of 0.897 g / cm³. 3 .

[0090] Experimental Example

[0091] Barrier sheets with a three-layer structure (PB-1 layer, hot melt adhesive layer, and EVOH layer stacked along the thickness direction) were prepared using a three-layer casting machine. The PB-1 layer was made from Mitsui Chemicals P5250N (Japan), with a thickness of 300 μm. The hot melt adhesive layer was made from hot melt adhesive granules prepared in the various examples and comparative examples, with a thickness of 30 μm. The EVOH layer was made from Sinopec EV3201, with a thickness of 30 μm. The extrusion temperature was set as follows:

[0092] Extrusion temperatures for each zone of PB-1 layer: 130℃, 200℃, 200℃, 200℃;

[0093] Extrusion temperatures for each zone of the hot melt adhesive layer: 180℃, 230℃, 230℃, 230℃;

[0094] Extrusion temperatures for each zone of the EVOH layer: 130℃, 200℃, 200℃, 200℃.

[0095] The processing performance of the barrier sheet is evaluated. If the barrier sheet does not exhibit poor stiffness or uneven distribution of the hot melt adhesive layer, it is considered to have good processing performance. If the barrier sheet curls, it is considered to have poor stiffness. If the barrier sheet appears foggy or has spots when observed with the naked eye, it is considered to have uneven distribution of the hot melt adhesive layer.

[0096] Peel strength: The T-peel strength of the prepared barrier sheet was tested according to GB / T 2791-1995, with a peel speed of 50 mm / min;

[0097] X1: The prepared barrier sheet was tested directly at room temperature of 25°C;

[0098] X2: The prepared barrier sheet was frozen at -20℃ for 1 hour and then tested at room temperature of 25℃.

[0099] X3: The prepared barrier sheet was boiled in water at 100°C for 1 hour and then tested at room temperature at 25°C.

[0100] The test results are shown in Table 1.

[0101] Table 1 Test results of different barrier sheets

[0102]

[0103] The test results above show that the hot melt adhesive for polybutene of the present invention, by introducing polybutene-1 grafted with maleic anhydride, combined with polybutene-1 and optionally an elastomer, can significantly improve the adhesive strength and adhesion durability of the hot melt adhesive to polybutene-1 and EVOH, and has no odor or small molecule migration, and has good processing performance.

[0104] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. Hot-melt adhesive for polybutene, characterized by the fact that it comprises: The polybutene-1 grafted maleic anhydride comprises the following components by mass percentage: polybutene-1 grafted maleic anhydride 10% to 30%, polybutene-1 matrix 50% to 80%, elastomer 0% to 20%, and antioxidant 0.1% to 1%. The grafting rate of maleic anhydride in the polybutene-1 grafted maleic anhydride is 0.5wt% to 2wt%. The density of the polybutene-1 in the polybutene-1 grafted maleic anhydride and of the polybutene-1 matrix is > 0.91 g / cm 3 .

2. The hot melt adhesive for polybutylene according to claim 1, characterized by, The melt index of the polybutene-1 in the polybutene-1 grafted maleic anhydride and the polybutene-1 matrix under the condition of 190℃ / 2.16kg is ≤5g / 10min.

3. The hot melt adhesive for polybutene according to claim 1, characterized by, The polybutene-1 grafted maleic anhydride is mainly prepared by reacting the following components by mass percentage: polybutene-1 95% to 98.7%, maleic anhydride 1% to 4%, and initiator 0.3% to 1%.

4. The hot melt adhesive for polybutene according to claim 3, characterized by, The preparation of the polybutene-1 grafted maleic anhydride comprises: mixing the polybutene-1, maleic anhydride, and initiator in proportion, and then performing melt extrusion; in the melt extrusion, vacuum treatment is performed at the end of the extruder; The length-diameter ratio of the twin-screw extruder used in the melt extrusion is ≥48:

1.

5. The hot melt adhesive for polybutene according to claim 1, characterized by, The elastomer comprises at least one of ethylene-based elastomer, propylene-based elastomer, and butene-based elastomer.

6. The hot melt adhesive for polybutene according to claim 1, characterized by, The elastomer comprises ethylene-propylene rubber.

7. The hot melt adhesive for polybutene according to claim 1, characterized by, The mass ratio of the polybutene-1 matrix to the elastomer is (5 to 15):

1.

8. The process for the preparation of hot-melt glue for polybutylene according to any one of claims 1 to 7, characterized in that, The melt extrusion granulation comprises the following steps: mixing the polybutene-1 grafted maleic anhydride, polybutene-1 matrix, optional elastomer, and antioxidant in proportion, and then performing melt extrusion granulation.

9. The preparation method according to claim 8, characterized in that, In the melt extrusion granulation, the temperature is 70 to 200℃.

10. A barrier sheet, characterized by The hot melt adhesive layer is prepared from the hot melt adhesive for polybutene according to any one of claims 1 to 7.

11. The barrier sheet of claim 10, wherein, The thickness of the hot melt adhesive layer is 5 to 50μm.

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