Polyphenyl ether modified EVA hot melt adhesive and preparation method thereof

Abstract

The invention relates to the technical field of polymer composite material processing, and discloses a polyphenyl ether modified EVA (Ethylene Vinyl Acetate) hot melt adhesive and a preparation method thereof. The hot melt adhesive is prepared from the following components in parts by weight: 35 to 50 parts of EVA (Ethylene Vinyl Acetate) resin, 5 to 20 parts of polyphenyl ether, 30 to 60 parts of tackifying resin, 5 to 20 parts of wax and 0.4 to 0.8 part of composite antioxidant. EVA and PPE in a specific ratio are selected as base materials (wherein EVA is the main base material), and a proper amount of tackifying resin is added into the system to modify the EVA hot melt adhesive, so that the melt viscosity of the system is reduced, the cohesion of the hot melt adhesive and the wettability of the hot melt adhesive on a bonding interface are improved, the bonding strength is enhanced, and the performance is further improved; the tackifying resin is low in volatile matter, and the softening point of the tackifying resin is higher than that of EVA resin, so that the softening point of the hot melt adhesive can be further improved, and the low-temperature resistance, mechanical property and ageing resistance of the hot melt adhesive are improved.

Description

Technical Field

[0001] The invention relates to the technical field of polymer composite material processing, and in particular to a polyphenylene ether modified EVA hot melt adhesive and a preparation method thereof. Background Art

[0002] Ethylene-vinyl acetate (EVA) is a stable, odorless, non-toxic thermoplastic obtained by copolymerization of ethylene monomer and vinyl acetate (VA) monomer under the action of a catalyst. The introduction of vinyl acetate side groups makes EVA have high polarity, anti-aging, weather resistance, discoloration resistance and excellent mechanical properties, and it is low-cost, green and environmentally friendly, and has excellent processing performance. The performance and application of EVA are related to the content of vinyl acetate (VA), and the difference in MFR also makes its use different. The processing technology of different brands of EVA materials is different, and the difference in processing technology has a great influence on its modification effect and the performance and application of the product. Choosing the best processing technology according to the different EVA brands and application fields can maximize the excellent performance of EVA materials.

[0003] Polyphenylene ether (PPE) is a white powder, non-toxic, transparent, low relative density, excellent mechanical strength, stress relaxation resistance, creep resistance, heat resistance, water resistance, water vapor resistance, dimensional stability, outstanding electrical insulation, good wear resistance and electrical properties, and the dielectric properties of PPE rank first among plastics. However, its poor melt fluidity, difficulty in processing and molding, and inability to resist non-polar solvents have greatly limited its application. Therefore, low-viscosity and low-molecular-weight polyphenylene ether resins are used to reduce or avoid problems such as difficulty in processing and molding.

[0004] However, the solubility parameters of EVA and PPE are quite different, and their compatibility is poor. It is not suitable to add too much PPE. Only a small amount of PPE is introduced into the EVA hot melt adhesive system to achieve better results.

[0005] The development of EVA hot melt adhesive both at home and abroad has shown a positive development trend, especially in the field of book binding, EVA hot melt adhesive has become an indispensable key material. Through modification, compounding and other technical means, the performance of EVA hot melt adhesive has been further improved, and its application areas have also expanded accordingly. This development trend not only reflects the progress of industry technology, but also reflects the changes in market demand. With the continuous advancement of technology and the expansion of application areas, EVA hot melt adhesive has become increasingly important in the domestic and foreign markets. At present, there are many types of EVA hot melt adhesives on the market, but there are still only a handful of products with a wide range of applications. Summary of the invention

[0006] The purpose of the present invention is to solve the above technical problems and to provide a polyphenylene ether modified EVA hot melt adhesive and a preparation method thereof.

[0007] The technical solutions adopted are as follows: The first aspect of the present invention provides a polyphenylene ether modified EVA hot melt adhesive, which comprises the following components in parts by weight: 35-50 parts of EVA resin, 5-20 parts of polyphenylene ether, 30-60 parts of tackifying resin, 5-20 parts of wax, and 0.4-0.8 parts of composite antioxidant; The EVA resin has a softening point of 60-80° C. and a VA content of 19wt%-40wt%; The number average molecular weight of the polyphenylene ether is 1000-3000, and the intrinsic viscosity is 0.5-1.5 dL / g.

[0008] Preferably, the EVA resin is EVA resin I and EVA resin II in a content ratio of 1:4-6, or the EVA resin is EVA resin I and EVA resin III in a content ratio of 1:0.5-2.

[0009] Preferably, the tackifying resin is at least one or more of hydrogenated terpene resin, rosin resin, modified rosin derivatives, petroleum resin, hydrogenated modified petroleum resin, copolymerized modified petroleum resin, and grafted modified petroleum resin.

[0010] Preferably, the tackifying resin is a petroleum resin II and a petroleum resin I in a content ratio of 1:0-1, or the tackifying resin is a petroleum resin II and a hydrogenated terpene resin in a content ratio of 1:0-1.

[0011] Preferably, the wax is at least one of paraffin wax, polyethylene wax, polypropylene wax and Fischer-Tropsch wax.

[0012] Preferably, the wax is Fischer-Tropsch wax I and Fischer-Tropsch wax II in a content ratio of 1:0-2.

[0013] Further preferably, the composite antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a content ratio of 1:1.

[0014] The second aspect of the present invention provides a method for preparing the polyphenylene ether modified EVA hot melt adhesive as described in the first aspect of the present invention, characterized in that the raw materials are weighed according to the weight ratio, put into a high-speed mixer for uniform mixing, and then blended and extruded through a twin-screw extruder, cooled through an underwater pelletizing system, and dried; The mixing conditions at least meet the following requirements: stirring speed is 300 rpm, and the time is 5 to 8 min; The parameter settings of the twin-screw extruder at least meet the following requirements: temperature is 50-160° C., and main engine speed is 22-27 Hz.

[0015] Beneficial effects of the present invention: (1) The present invention selects EVA and PPE with a specific ratio as the matrix material (EVA is the main matrix material). The addition of PPE improves the cohesion and mechanical strength of the EVA hot melt adhesive. An appropriate amount of tackifying resin is added to this system to modify the EVA hot melt adhesive, reduce the melt viscosity of the system, improve the cohesion of the hot melt adhesive and the wettability at the bonding interface, thereby enhancing the bonding strength and further improving the performance. The tackifying resin has low volatility, and the use of a resin with a softening point higher than that of EVA resin can further increase the softening point of the hot melt adhesive, improve its low temperature resistance, mechanical properties and anti-aging properties; (2) The present invention selects a specific content of wax as a modification aid to reduce the melt viscosity of the hot melt adhesive, improve the wettability of the hot melt adhesive, and thus improve the bonding strength. At the same time, the introduction of wax can improve the thermal properties, hardness, and mechanical properties of the hot melt adhesive, as well as adjust the open time and curing time of the hot melt adhesive. A specific content of high-temperature composite antioxidant is added, and in combination with the other technical features of the present invention, the obtained EVA hot melt adhesive has suitable fluidity, ultra-high bonding strength, long aging resistance, and excellent curing time that meets actual requirements. It also has excellent toughness, heat resistance, low temperature resistance and other comprehensive properties; (3) According to the functional requirements of the product, the present invention can add suitable functional additives to the formula of the present invention to achieve the desired performance. For example, if a proper amount of filler is added in the present invention, the heat resistance of the hot melt adhesive can be improved, the mechanical properties can be reinforced, the shrinkage of the hot melt adhesive can be reduced, the fluidity of the hot melt adhesive can be controlled, and the cost can be reduced. DETAILED DESCRIPTION

[0016] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0017] It should be noted that, in various aspects of the present invention, for the same components in various aspects, the present invention is described only once in one aspect without repeated description, which should not be understood by those skilled in the art as a limitation of the present invention.

[0018] In the present invention, polyphenylene ether is an important technical feature. In the present invention, polyphenylene ether with low molecular weight and low viscosity is selected because the increase of molecular weight of polyphenylene ether and the increase of system viscosity are not conducive to the dynamic process of system compatibility.

[0019] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, the raw materials are all commercially available.

[0020] In the following examples, polyphenylene ether, with a number average molecular weight of 1600 and an intrinsic viscosity of 0.09 dL / g, was purchased from SABIC with a brand name of SA90; EVA resin: EVA resin I, purchased from LG Group of South Korea, brand LG33045, softening point 62°C, VA content 28wt%; EVA resin II, purchased from LG Group of South Korea, brand LG28150, softening point 70°C, VA content 28wt%; EVA resin III, purchased from LG Group of South Korea, brand LG28400, softening point 68°C, VA content 28wt%; Tackifying resin: Petroleum resin I, purchased from Henghe Materials Technology Co., Ltd., brand HM-1200; Petroleum resin II, purchased from Henghe Materials Technology Co., Ltd., brand HM-1000; Hydrogenated terpene resin, purchased from Hengfeng Petrochemical Co., Ltd., brand TH100; wax: Fischer-Tropsch wax I, purchased from Shaanxi Future Energy Chemical Co., Ltd., brand WL-115; Fischer-Tropsch wax II, purchased from Shaanxi Future Energy Chemical Co., Ltd., brand WL-108; Compound antioxidant: Pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, purchased from Jiangsu Jiyi New Materials Co., Ltd., brand name Antioxidant 1010; Tris[2,4-di-tert-butylphenyl]phosphite was purchased from Jiangsu Jiyi New Materials Co., Ltd. with the brand name Antioxidant 168.

[0021] Embodiment 1: A polyphenylene ether modified EVA hot melt adhesive, comprising the following components in parts by weight: 35 parts of EVA resin, 40 parts of tackifying resin, 10 parts of polyphenylene ether, 15 parts of wax, and 0.4 parts of composite antioxidant; The EVA resin is EVA resin I and EVA resin II with a content ratio of 1:6; The tackifying resin is petroleum resin I and petroleum resin II with a content ratio of 0:1; The waxes are Fischer-Tropsch wax I and Fischer-Tropsch wax II in a content ratio of 1:2; The composite antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a content ratio of 1:1, wherein the pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is 0.2 parts by weight; The preparation method of polyphenylene ether modified EVA hot melt adhesive is as follows (according to the formula and process parameters in Table 1): The raw materials are weighed according to the weight ratio, added into a high-speed mixer and mixed evenly, then blended and extruded through a twin-screw extruder, cooled and pelletized through an underwater pelletizing system, and dried.

[0022] Embodiment 2: A polyphenylene ether modified EVA hot melt adhesive, comprising the following components in parts by weight: 35 parts of EVA resin, 30 parts of tackifying resin, 15 parts of polyphenylene ether, 20 parts of wax, and 0.4 parts of composite antioxidant; The EVA resin is EVA resin I and EVA resin III with a content ratio of 2:1; The tackifying resin is petroleum resin I and petroleum resin II in a content ratio of 1:1; The waxes are Fischer-Tropsch wax I and Fischer-Tropsch wax II in a content ratio of 1:2; The composite antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a content ratio of 1:1, wherein the pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is 0.2 parts by weight; The preparation method of polyphenylene ether modified EVA hot melt adhesive is as follows (according to the formula and process parameters in Table 1): The raw materials are weighed according to the weight ratio, added into a high-speed mixer and mixed evenly, then blended and extruded through a twin-screw extruder, cooled and pelletized through an underwater pelletizing system, and dried.

[0023] Embodiment 3: A polyphenylene ether modified EVA hot melt adhesive, comprising the following components in parts by weight: 45 parts of EVA resin, 40 parts of tackifying resin, 5 parts of polyphenylene ether, 10 parts of wax, and 0.8 parts of composite antioxidant; The EVA resin is EVA resin I and EVA resin III with a content ratio of 1:2; The tackifying resin is petroleum resin I and petroleum resin II in a content ratio of 1:1; The waxes are Fischer-Tropsch wax I and Fischer-Tropsch wax II in a content ratio of 1:0; The composite antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a content ratio of 1:1, wherein the pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] is 0.4 parts by weight; The preparation method of polyphenylene ether modified EVA hot melt adhesive is as follows (according to the formula and process parameters in Table 1): The raw materials are weighed according to the weight ratio, added into a high-speed mixer and mixed evenly, then blended and extruded through a twin-screw extruder, cooled and pelletized through an underwater pelletizing system, and dried.

[0024] Example 4 A polyphenylene ether modified EVA hot melt adhesive, comprising the following components in parts by weight: 37 parts of EVA resin, 35 parts of tackifying resin, 18 parts of polyphenylene ether, 10 parts of wax, and 0.6 parts of composite antioxidant; The EVA resin is EVA resin I and EVA resin II with a content ratio of 7:30; The tackifying resin is a petroleum resin II and a hydrogenated terpene resin in a content ratio of 1:1; The waxes are Fischer-Tropsch wax I and Fischer-Tropsch wax II in a content ratio of 1:1; The composite antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a content ratio of 2:1, wherein the pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is 0.2 parts by weight; The preparation method of polyphenylene ether modified EVA hot melt adhesive is as follows (according to the formula and process parameters in Table 1): The raw materials are weighed according to the weight ratio, added into a high-speed mixer and mixed evenly, then blended and extruded through a twin-screw extruder, cooled and pelletized through an underwater pelletizing system, and dried.

[0025] Comparative Example 1: This example is carried out according to the method in Example 1, except that polyphenylene ether with an intrinsic viscosity of 0.38 dL / g is used to replace the polyphenylene ether, and the remaining steps and methods are the same as in Example 1.

[0026] Comparative Example 2: This example is carried out according to the method in Example 1, except that in the composite antioxidant, the content ratio of the tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate and the tris[2,4-di-tert-butylphenyl]phosphite is 0:1, and the remaining steps and methods are the same as in Example 1.

[0027] Comparative Example 3: This example is carried out according to the method in Example 1, except that no tackifying resin is added, and the remaining steps and methods are the same as in Example 1.

[0028] Comparative Example 4: This example is carried out according to the method in Example 1, except that wax is not added, and the remaining steps and methods are the same as in Example 1.

[0029]

[0030] Test Example 1: The polyphenylene ether modified EVA hot melt adhesives prepared in the above examples and comparative examples were placed in an environment with a temperature of 23±2°C and a relative humidity of 50±10% for 48 hours, and then the performance was tested. Melt viscosity is tested according to HG / T 3660 standard, test temperature (170℃±1℃); The softening point is tested according to GB / T 15332 standard; The tensile strength and elongation at break are tested in accordance with GB / T 528 standard. The hardness is tested according to GB / T 531 standard; Thermal stability is tested according to GBT 16998 standard; The brittle temperature is tested according to GB / T 1682 standard; The test results are shown in Table 2;

[0031] It can be seen from the results in Table 2 that the technical solution of the present invention, in combination with the specific process of the twin-screw extruder, controlling the amount of polyphenylene ether added and other technical features, solves the compatibility problem of the raw materials well. The polyphenylene ether modified EVA hot melt adhesive obtained in the embodiment of the present invention has significantly better mechanical properties, aging resistance, heat resistance and low temperature resistance.

[0032] Moreover, it can be seen from the results in Table 2 that the hot melt adhesive modified by adding different amounts and types of polyphenylene ether has a great influence on the obtained performance. Specifically, in Example 1, polyphenylene ether with a larger molecular weight and a smaller melt index is used instead, and problems such as poor material compatibility, high system viscosity and difficulty in processing will occur; in Example 2, no primary antioxidant is added, and the oxidation rate is significantly accelerated under high temperature environment, that is, it is necessary to add an appropriate amount of primary antioxidant; in Example 3, no tackifying resin is added, and the system viscosity increases, the hot melt adhesive hardness is small, the bonding strength is low, and the wetting angle increases during use, which affects the use effect; in Example 4, no wax is added, and the system viscosity increases, the hot melt adhesive hardness is small, the wetting angle increases, and the curing time is greatly extended, thereby affecting the use effect. It is verified through other experiments that excessive addition of wax will also lead to the problem of too short curing time.

[0033] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A polyphenylene ether modified EVA hot melt adhesive, characterized in that: The composition is calculated by weight: 35-50 parts of EVA resin, 5-20 parts of polyphenylene ether, 30-60 parts of tackifying resin, 5-20 parts of wax, and 0.4-0.8 parts of composite antioxidant; The EVA resin has a softening point of 60-80° C. and a VA content of 19wt%-40wt%; The number average molecular weight of the polyphenylene ether is 1000-3000, and the intrinsic viscosity is 0.5-1.5 dL / g.

2. The polyphenylene ether modified EVA hot melt adhesive according to claim 1, wherein: The EVA resin is EVA resin I and EVA resin II in a content ratio of 1:4-6, or the EVA resin is EVA resin I and EVA resin III in a content ratio of 1:0.5-2.

3. The polyphenylene ether modified EVA hot melt adhesive according to claim 1 or 2, wherein: The tackifying resin is at least one or more of hydrogenated terpene resin, rosin resin, modified rosin derivatives, petroleum resin, hydrogenated modified petroleum resin, copolymerized modified petroleum resin, and grafted modified petroleum resin; And / or, the tackifying resin is a petroleum resin II and a petroleum resin I in a content ratio of 1:0-1, or the tackifying resin is a petroleum resin II and a hydrogenated terpene resin in a content ratio of 1:0-1.

4. The polyphenylene ether modified EVA hot melt adhesive according to claim 1 or 2, wherein: The wax is at least one of paraffin wax, polyethylene wax, polypropylene wax, and Fischer-Tropsch wax; And / or, the wax is Fischer-Tropsch wax I and Fischer-Tropsch wax II with a content ratio of 1:0-2.

5. The polyphenylene ether modified EVA hot melt adhesive according to claim 1 or 2, characterized in that: The composite antioxidant is pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] and tris[2,4-di-tert-butylphenyl]phosphite in a content ratio of 1:

1.

6. A method for preparing a polyphenylene ether modified EVA hot melt adhesive as claimed in any one of claims 1 to 5, characterized in that: The raw materials are weighed according to the weight ratio, put into a high-speed mixer to mix evenly, and then blended and extruded by a twin-screw extruder, cooled by an underwater pelletizing system, and dried; The mixing conditions at least meet the following requirements: stirring speed is 300 rpm, and the time is 5 to 8 min; The parameter settings of the twin-screw extruder at least meet the following requirements: temperature is 50-160° C., and main engine speed is 22-27 Hz.

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