Non-stringing clean hot melt adhesive composition, and preparation method therefor and use thereof

Abstract

A hot melt adhesive composition, a hot melt adhesive, and a preparation method for the hot melt adhesive. The hot melt adhesive composition comprises a base polymer, a tackifying resin, and an antioxidant. The base polymer comprises a styrene block copolymer, an amorphous α-olefin copolymer, and an ethylene-vinyl acetate copolymer. The tackifying resin is a pure monomer resin. The hot melt adhesive is prepared mainly from the hot melt adhesive composition. The hot melt adhesive has a non-stringing effect during coating. The hot melt adhesive composition or the hot melt adhesive is applied to the industrial assembly or packaging industry.

Description

A non-stringy, clean hot melt adhesive composition, its preparation method and application

[0001] Relevant publicly available cross-references

[0002] This disclosure claims priority to Chinese Patent Publication 202411660069.7, filed on November 20, 2024, entitled “Hot melt adhesive composition, hot melt adhesive and preparation method and application thereof”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of adhesive technology, and more particularly to a non-stringy, clean hot melt adhesive composition, its preparation method, and its application. Background Technology

[0004] Hot melt adhesive is used by heating and melting it into a liquid using equipment, and then transferring it onto the substrate. The coating methods usually include scraping, roller coating, and nozzle spraying, all of which commonly suffer from stringing problems.

[0005] Stringing in hot melt adhesives can accumulate on equipment, requiring frequent cleaning and potentially leading to downtime and reduced production efficiency. It can also negatively impact the product's appearance and even its bonding properties. Common methods to reduce stringing include increasing the proportion of viscosity modifiers or decreasing the proportion of polymers. However, both methods have adverse effects on the performance of hot melt adhesives, such as decreased adhesion and weakened weather resistance.

[0006] Therefore, it is both necessary and urgent to research and develop a hot melt adhesive composition that has a non-stringing coating effect.

[0007] In view of this, this disclosure is hereby made. Summary of the Invention

[0008] The first objective of this disclosure is to provide a hot melt adhesive composition that, at a high temperature of 150–170°C, exhibits poorer fluidity than conventional hot melt adhesives and shrinks. When applied, the hot melt adhesive liquid shrinks rapidly without producing adhesive threads, resulting in a clean and thread-free coating.

[0009] A second object of this disclosure includes providing a hot melt adhesive prepared primarily from the above-described hot melt adhesive composition.

[0010] A third objective of this disclosure includes providing a method for preparing a hot melt adhesive.

[0011] A fourth object of this disclosure includes providing a hot melt adhesive composition or an application of a hot melt adhesive.

[0012] To achieve the above-mentioned objectives of this disclosure, the following technical solutions may be adopted:

[0013] This disclosure provides a hot melt adhesive composition comprising: a base polymer, a tackifying resin, and an antioxidant, wherein:

[0014] The basic polymers include styrene block copolymers, amorphous α-olefin copolymers, and ethylene-vinyl acetate copolymers;

[0015] The tackifying resin is a pure monomeric resin.

[0016] In some alternative embodiments, the hot melt adhesive composition comprises, by weight percentage: 30-60% base polymer, 35-70% tackifying resin, and 0-2% antioxidant, wherein the sum of the weight percentages of all components in the hot melt adhesive composition is 100%.

[0017] In some alternative embodiments, the hot melt adhesive composition comprises, by weight percentage: 32-42% base polymer, 37-67% tackifying resin, and 1% antioxidant, wherein the sum of the weight percentages of all components in the hot melt adhesive composition is 100%.

[0018] In some alternative implementations, the base polymer contains:

[0019] The mass ratio of styrene block copolymer to amorphous α-olefin copolymer is 1:0.5 to 2, and the mass ratio of the sum of styrene block copolymer and amorphous α-olefin copolymer to ethylene-vinyl acetate copolymer is 1:0.5 to 2.

[0020] In some alternative embodiments, the base polymer also includes an ethylene-butyl acrylate copolymer.

[0021] In some alternative embodiments, the content of ethylene-butyl acrylate copolymer in the hot melt adhesive composition is 0-4%.

[0022] In some alternative embodiments, the tackifying resin includes at least one of SA100, SA85, Y100, Y120, F100, and W100.

[0023] In some alternative embodiments, the tackifying resin has a ring and ball softening point of 85-100°C.

[0024] In some alternative embodiments, the tackifying resin is W series products.

[0025] In some alternative embodiments, the melt index of the styrene block copolymer is 27–220 g / 10 min.

[0026] In some alternative embodiments, the melt viscosity of the amorphous α-olefin copolymer at 190°C is not greater than 3000 cps.

[0027] In some alternative embodiments, the melt index of the ethylene-vinyl acetate copolymer is 400–800 g / 10 min.

[0028] In some optional embodiments, the VA content of the ethylene-vinyl acetate copolymer is ≥30%.

[0029] In some alternative embodiments, the antioxidant is an inhibitory phenolic antioxidant. This disclosure also provides a hot melt adhesive prepared primarily from the above-described hot melt adhesive composition.

[0030] This disclosure also provides a method for preparing the above-mentioned hot melt adhesive, comprising:

[0031] (A) The tackifying resin and antioxidant are mixed and melted to obtain mixture A;

[0032] (B) After mixing the styrene block copolymer with mixture A, add the amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer, and optional ethylene-butyl acrylate copolymer in sequence, mix well, and obtain mixture B;

[0033] (C) The mixture B is cooled, granulated and dried in sequence to obtain hot melt adhesive.

[0034] In some alternative implementations, step (B) is performed under vacuum conditions, wherein the vacuum level is -0.09 to -0.07 MPa.

[0035] In some alternative implementations, step (B) includes the following steps:

[0036] After mixing the styrene block copolymer with mixture A, the mixture is stirred for 1 to 2 hours under the conditions of vacuum degree of -0.09 to -0.07 MPa, temperature of 120 to 130 °C and rotation speed of 80 to 100 r / min to completely melt the styrene block copolymer into the mixture. Then, while maintaining the temperature, amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer and optionally ethylene-butyl acrylate copolymer are added in sequence, and the mixture is stirred for another 1 to 2 hours to obtain mixture B.

[0037] In some alternative embodiments, step (C) cooling is performed under vacuum conditions, with a vacuum degree of -0.09 to -0.07 MPa, and the temperature of mixture B after cooling is 90 to 100°C.

[0038] This disclosure also provides an application of the above-described hot melt adhesive composition or the above-described hot melt adhesive in the preparation of industrial assembly or packaging bonding products.

[0039] Compared with the prior art, the beneficial effects of this disclosure include:

[0040] The hot melt adhesive composition disclosed herein includes a base polymer, a tackifying resin, and an antioxidant, wherein the base polymer includes styrene block copolymers, amorphous α-olefin copolymers, and ethylene-vinyl acetate copolymers. Because the base polymers in the above-mentioned hot melt adhesive composition include styrene block copolymers, amorphous α-olefin copolymers, and ethylene-vinyl acetate copolymers, and because the molecular structures and polarities of these three polymers are different, and the compatibility between pure monomer resins and these three polymers is also poor, the hot melt adhesive composition disclosed herein exhibits poorer fluidity than conventional hot melt adhesives at high temperatures of 150–170°C and exhibits a shrinking state. During application, the hot melt adhesive liquid shrinks rapidly without producing strings, thus achieving a clean, non-stringy effect.

[0041] The hot melt adhesive disclosed herein is mainly prepared from the above-mentioned hot melt adhesive composition. Due to the selection and proportioning of raw materials in the above-mentioned hot melt adhesive composition, the hot melt adhesive exhibits a shrinking state at high temperatures, and during application, the hot melt adhesive liquid shrinks rapidly without producing adhesive threads.

[0042] The hot melt adhesive preparation method disclosed herein first involves mixing and melting a tackifying resin and an antioxidant to obtain mixture A; then, a styrene block copolymer is mixed with mixture A, followed by the sequential addition of an amorphous α-olefin copolymer, an ethylene-vinyl acetate copolymer, and optionally an ethylene-butyl acrylate copolymer, which are then mixed thoroughly. The mixture is then subjected to cooling, granulation, and drying to obtain the hot melt adhesive. This preparation method has the technical advantages of simple processing and ease of operation.

[0043] The hot melt adhesive composition or hot melt adhesive provided in this disclosure can be widely used in industrial assembly or packaging industries. Detailed Implementation

[0044] The technical solutions of this disclosure will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this disclosure, not all embodiments. Based on the embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0045] According to one aspect of this disclosure, a hot melt adhesive composition is provided, comprising: a base polymer, a tackifying resin, and an antioxidant, wherein:

[0046] The basic polymers include styrene block copolymers, amorphous α-olefin copolymers, and ethylene-vinyl acetate copolymers;

[0047] The tackifying resin is a pure monomeric resin.

[0048] The hot melt adhesive composition disclosed herein includes a base polymer, a tackifying resin, and an antioxidant, wherein the base polymer includes a styrene block copolymer, an amorphous α-olefin copolymer, and an ethylene-vinyl acetate copolymer. Because the base polymers in the above-mentioned hot melt adhesive composition include styrene block copolymers, amorphous α-olefin copolymers, and ethylene-vinyl acetate copolymers, and because the molecular structures and polarities of these three polymers are different, and the compatibility between the pure monomer resin and these three polymers is also poor, the hot melt adhesive composition disclosed herein exhibits poorer fluidity than conventional hot melt adhesives at high temperatures of 150–170°C and exhibits a shrinking state. During application, the hot melt adhesive liquid shrinks rapidly without producing strings, thus achieving a clean, non-stringy effect.

[0049] In some alternative embodiments, the tackifying resin is a pure monomer resin, such as: Kraton SA100 / SA85, Ganges Y100 / Y120, Eastman F100, Clayville W100, etc.

[0050] In some alternative embodiments, the melt index of the styrene block copolymer is 27–220 g / 10 min.

[0051] In some alternative embodiments, the melt viscosity of the amorphous α-olefin copolymer at 190°C is not greater than 3000 cps.

[0052] In some alternative embodiments, the melt index of the ethylene-vinyl acetate copolymer is 400–800 g / 10 min.

[0053] In some optional embodiments, the VA content of the ethylene-vinyl acetate copolymer is ≥30%.

[0054] In some alternative embodiments, the tackifying resin is a pure monomeric resin with a ring and ball softening point of 85-100°C, such as that from Clayville Corporation. W series products.

[0055] In some alternative embodiments, the antioxidant is an inhibitory phenolic antioxidant.

[0056] In a preferred embodiment provided in this disclosure, the hot melt adhesive composition comprises, by mass percentage: 30-60% base polymer, 35-70% tackifying resin, and 0-2% antioxidant, wherein the sum of the mass percentages of each component in the hot melt adhesive composition is 100%.

[0057] As a preferred embodiment, the hot melt adhesive composition provided in this disclosure consists of a base polymer, a tackifying resin, and an antioxidant, and does not contain viscosity modifiers such as mineral oil and wax, so the cohesive strength and adhesive strength are not weakened; at the same time, this application does not require reducing the content of the base polymer; in addition, the hot melt adhesive composition provided in this disclosure also has a long working time and is suitable for industries such as industrial assembly.

[0058] It should be noted that the base polymer in a hot melt adhesive formulation acts as the skeleton of the hot melt adhesive, providing sufficient cohesive strength. Reducing its proportion will decrease the cohesive strength of the adhesive, making it softer and unable to achieve sufficient bonding strength. The hot melt adhesive composition provided in this disclosure, through the compounding of base polymer, tackifying resin, and antioxidant, can maintain the content of the base polymer at 30%–60%, thereby giving the hot melt adhesive better bonding strength.

[0059] In the preferred embodiment described above, the hot melt adhesive composition comprises: 32-42% base polymer, 37-67% tackifying resin, and 1% antioxidant, wherein the sum of the mass percentages of each component in the hot melt adhesive composition is 100%.

[0060] In this disclosure, the technical effect of the hot melt adhesive composition is further optimized by further adjusting and optimizing the proportion of each component raw material.

[0061] In a preferred embodiment of this disclosure, the base polymer contains:

[0062] The mass ratio of styrene block copolymer to amorphous α-olefin copolymer is 1:0.5 to 1:2, and the mass ratio of the sum of styrene block copolymer and amorphous α-olefin copolymer to ethylene-vinyl acetate copolymer is 1:0.5 to 1:2.

[0063] In a preferred embodiment, when the mass ratio of the styrene block copolymer to the amorphous α-olefin copolymer is 1:0.5 to 1:2, and the mass ratio of the sum of the styrene block copolymer and the amorphous α-olefin copolymer to the ethylene-vinyl acetate copolymer is 1:0.5 to 1:2, the hot melt adhesive composition has a better anti-firing effect, and the firing state can reach level 2 after testing.

[0064] Right now:

[0065] The mass ratio of styrene block copolymer to amorphous α-olefin copolymer is 1:0.5 to 1:2;

[0066] The mass ratio of (styrene block copolymer + amorphous α-olefin copolymer) to ethylene-vinyl acetate copolymer is 1:0.5 to 1:2.

[0067] In a preferred embodiment of this disclosure, the base polymer further includes an ethylene-butyl acrylate copolymer.

[0068] In the preferred embodiment described above, the content of ethylene-butyl acrylate copolymer in the hot melt adhesive composition is 0-4%.

[0069] As a preferred embodiment, this disclosure has found through research that when ethylene-butyl acrylate copolymer is further added to the above-mentioned base polymer, the resulting hot melt adhesive composition exhibits a more pronounced shrinkage state at a high temperature of 150-170°C, and the stringing state can reach level 1, since the molecular structure and polarity of ethylene-butyl acrylate copolymer are different from those of the other three polymers.

[0070] In some alternative embodiments, the ethylene-butyl acrylate copolymer has a melt index of ≥40 g / 10 min and a butyl acrylate content of greater than 30%.

[0071] According to one aspect of this disclosure, a hot melt adhesive is provided, which is mainly prepared from the above-described hot melt adhesive composition.

[0072] The hot melt adhesive provided in this disclosure is mainly prepared from the above-mentioned hot melt adhesive composition. Due to the selection and content ratio of the raw materials in the above-mentioned hot melt adhesive composition, the hot melt adhesive has poorer fluidity than conventional hot melt adhesives at a high temperature of 150-170°C and exhibits a shrinking state. When applied, the hot melt adhesive liquid shrinks rapidly without producing adhesive threads.

[0073] According to one aspect of this disclosure, a method for preparing the above-mentioned hot melt adhesive is also provided, comprising:

[0074] (A) The tackifying resin and antioxidant are mixed and melted to obtain mixture A;

[0075] (B) After mixing the styrene block copolymer with mixture A, add the amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer, and optional ethylene-butyl acrylate copolymer in sequence, mix well, and obtain mixture B;

[0076] (C) The mixture B is cooled, granulated and dried in sequence to obtain hot melt adhesive.

[0077] The hot melt adhesive preparation method disclosed herein involves first mixing and melting a tackifying resin and an antioxidant to obtain mixture A; then mixing a styrene block copolymer with mixture A, followed by sequentially adding an amorphous α-olefin copolymer, an ethylene-vinyl acetate copolymer, and optionally an ethylene-butyl acrylate copolymer and mixing them, and then sequentially cooling, granulating, and drying to obtain the hot melt adhesive. This preparation method has the technical advantages of simple processing and ease of operation.

[0078] In a preferred embodiment of this disclosure, step (B) is performed under vacuum conditions, wherein the vacuum degree is -0.09 to -0.07 MPa.

[0079] As a preferred embodiment, the hot melt adhesive of this disclosure is prepared under vacuum conditions, which can effectively avoid the generation of air bubbles in the hot melt adhesive.

[0080] In a preferred embodiment of this disclosure, step (B) includes the following steps:

[0081] After mixing the styrene block copolymer with mixture A, the mixture is stirred for 1 to 2 hours under the conditions of vacuum degree of -0.09 to -0.07 MPa, temperature of 120 to 130 °C and rotation speed of 80 to 100 r / min to completely melt the styrene block copolymer into the mixture. Then, while maintaining the temperature, amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer and optionally ethylene-butyl acrylate copolymer are added in sequence, and the mixture is stirred for another 1 to 2 hours to obtain mixture B.

[0082] In a preferred embodiment of this disclosure, step (C) cooling is performed under vacuum conditions, with a vacuum degree of -0.09 to -0.07 MPa, and the temperature of mixture B after cooling is 90 to 100°C.

[0083] According to one aspect of this disclosure, the present disclosure also provides the use of the above-described hot melt adhesive composition or the above-described hot melt adhesive in the preparation of industrial assembly or packaging bonding products.

[0084] The hot melt adhesive composition or hot melt adhesive provided in this disclosure can be widely used in industrial assembly or packaging industries.

[0085] The technical solutions of this disclosure will be further described below with reference to the embodiments.

[0086] The following embodiments of this disclosure use the following raw material selection as an example to prepare and test the performance of the hot melt adhesive composition provided in this disclosure:

[0087] 1. Styrene block copolymer G1648, purchased from Kraton, is referred to as polymer A in the following examples for clarity;

[0088] 2. The amorphous α-olefin copolymer is RT 53727, purchased from DLCHEMICAL Co., Ltd. in South Korea, and is referred to as polymer B in the following examples for clarity.

[0089] 3. The ethylene-vinyl acetate copolymer was EVATANE28800, purchased from ARKEMA, and is referred to as polymer C in the following examples for clarity.

[0090] 4. The ethylene-butyl acrylate copolymer is AC 34035, purchased from DuPont, USA, and is referred to as polymer D in the following examples for clarity.

[0091] 5. The tackifying resin is W-100, purchased from Clayville Company;

[0092] 6. Antioxidants are B 225, purchased from BASF.

[0093] Examples 1-3

[0094] A hot melt adhesive composition, the raw material composition of which is shown in Table 1.

[0095] The hot melt adhesive composition is prepared into a hot melt adhesive through the following steps:

[0096] S1: The tackifying resin and antioxidant are mixed and melted at 100℃-110℃ to obtain the molten mixture A;

[0097] S2: After mixing the styrene block copolymer with mixture A, under the conditions of vacuum degree (-0.09)~(-0.07)MPa, temperature of 120-130℃ and rotation speed of 80-100r / min, stir and mix for 1-2h to completely melt the styrene block copolymer into the mixture and ensure that there are no solid insoluble substances. Then, while keeping the temperature constant, add the amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer and ethylene-butyl acrylate copolymer in sequence, and stir and mix for another 1-2h to obtain mixture B.

[0098] S3: Mixture B is naturally cooled to 90-100℃ under a vacuum of (-0.09) to (-0.07) MPa, and then granulated and air-dried to obtain the hot melt adhesive composition.

[0099] Subsequently, the performance of the hot melt adhesive compositions prepared in the above embodiments was tested using the following methods:

[0100] (1) Viscosity test: Refer to "HG / T 3660-1999 Determination of melt viscosity of hot melt adhesives" and use a rotational viscometer for testing. The rotational viscometer model is Brookfield DV-2+PRO, the rotor is 27#, the rotation speed is 20 rpm, and it is purchased from Brookfield Corporation of the United States.

[0101] (2) Stringing test: The hot melt adhesive samples were tested for stringing using a Nordson MESA 14 glue gun. The test temperatures for the glue tank / throat / nozzle were 160℃ / 165℃ / 170℃, and the pressure was 4.0 bar. Each glue sample was sprayed 30 times. The stringing situation was observed and statistically analyzed. The results were recorded as follows according to the severity of stringing: 5 severe stringing, 4 more stringing, 3 moderate stringing, 2 slight stringing, and 1 no stringing.

[0102] Table 1

[0103] Examples 4-8

[0104] A hot melt adhesive composition, the raw material composition of which is shown in Table 2.

[0105] The steps for preparing the hot melt adhesive composition into a hot melt adhesive are the same as in Examples 1-3.

[0106] The method for testing the performance of the prepared hot melt adhesive composition is the same as in Examples 1-3.

[0107] Table 2

[0108] Examples 9-12

[0109] A hot melt adhesive composition, the raw material composition of which is shown in Table 3.

[0110] The steps for preparing the hot melt adhesive composition into a hot melt adhesive are the same as in Examples 1-3.

[0111] The method for testing the performance of the prepared hot melt adhesive composition is the same as in Examples 1-3.

[0112] Table 3

[0113] As can be seen from Examples 1 to 12 above, the hot melt adhesives prepared in Examples 1 to 12 of this application all have a certain anti-stringing effect. Among them, Examples 1 to 8, under the conditions of "polymer A:B = 1:(0.5-2)" and "polymer (A+B):C = 1:(0.5-2)", have a viscosity of 3300-8200 mPa·s at 160°C, and a stringing condition of 2 (slight stringing). Therefore, moderate viscosity and slight stringing have better technical effects.

[0114] Although the hot melt adhesives prepared in Examples 9 to 12 meet one of the conditions of "polymer A:B = 1:(0.5-2)" or "polymer (A+B):C = 1:(0.5-2)", their viscosity and stringing effect are not ideal, with stringing condition of 3 to 4.

[0115] Examples 13-16

[0116] A hot melt adhesive composition, the raw material composition of which is shown in Table 4.

[0117] The difference between Examples 13-16 and Example 5 is that polymer D is added and the amount of tackifying resin is reduced; otherwise, they are the same as Example 5.

[0118] Table 4

[0119] As can be seen from the table above, the hot melt adhesive compositions obtained in Examples 13 to 16 have a viscosity of 4200 to 10800 mPa·s at 160°C and a stringing condition of 1 to 3, that is, no stringing to moderate stringing. The stringing condition is better when the polymer D ratio is 2 to 4%.

[0120] Examples 17-19

[0121] A hot melt adhesive composition, the raw material composition of which is shown in Table 5.

[0122] The difference between Examples 17-19 and Example 13 is that the total mass of the polymer was changed, while all other aspects are the same as in Example 13.

[0123] Table 5

[0124] As can be seen from the table above, the clean hot melt adhesive compositions that do not string in Examples 17 to 19 have a viscosity of 2200 to 15600 mPa·s at 160°C and a stringing condition of 1 to 3, that is, no stringing to moderate stringing. The stringing condition is optimal when the polymer ratio is 32 to 42%.

[0125] Comparative Examples 1-7

[0126] A hot melt adhesive composition, the raw material composition of which is shown in Table 6.

[0127] The difference between this comparative example and Example 13 is that the choice of base polymer is different, but otherwise the same as in Example 13.

[0128] Table 6

[0129] As can be seen from the above, in the embodiments of Comparative Examples 1 to 4 that only contain a single polymer, the fiber pulling condition is 4-5, that is, more fiber pulling / severe fiber pulling; while in the embodiments of Comparative Examples 5 to 7 that contain two polymers A, B, and C, the fiber pulling condition is 4, that is, more fiber pulling.

[0130] Comparative Example 8

[0131] The difference between this comparative example and Example 13 is that: an equal amount of partially hydrogenated rosin polyol ester from Guangdong Kemaolin Chemical Co., Ltd. was used. KS2100 replaces tackifying resin W-100, and the rest is the same as in Example 13. See Table 7 for the specific composition.

[0132] Table 7

[0133] As can be seen from the above, partially hydrogenated rosin polyol esters and polymers A / B / C / D are all well compatible, improving the overall compatibility. The shrinkage effect is not obvious, and the fiber drawing is increased.

[0134] Comparative Example 9

[0135] This comparative example includes an additional 30 parts of viscosity modifier paraffin, see Table 8 for details.

[0136] Table 8

[0137] As can be seen from the above, the viscosity decreased significantly, and there was very little stringing, but the adhesion was significantly weakened.

[0138] Comparative Example 10

[0139] This comparative example is a comparative example with a reduced polymer ratio; see Table 9 for the specific composition.

[0140] Table 9

[0141] As can be seen from the above, reducing the polymer content lowers the viscosity of the adhesive and reduces fiber production, but the adhesive becomes more brittle, the bonding strength decreases significantly, and the low-temperature resistance is very poor.

[0142] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this disclosure, and are not intended to limit them. Although this disclosure 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 therein. Such 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 this disclosure. Industrial applicability

[0143] The hot melt adhesive composition provided in this disclosure exhibits poorer fluidity than conventional hot melt adhesives at high temperatures of 150–170°C and displays a shrinking state. During application, the hot melt adhesive liquid shrinks rapidly without forming threads, thus achieving a clean, non-threading effect. The hot melt adhesive containing the above-mentioned composition exhibits a shrinking state at high temperatures, and during application, the hot melt adhesive liquid shrinks rapidly without forming threads. The preparation method of the hot melt adhesive provided in this disclosure has the technical advantages of simple processing and ease of operation. The hot melt adhesive composition or hot melt adhesive provided in this disclosure can be widely used in industrial assembly or packaging industries.

Claims

1. A hot melt adhesive composition, characterized in that, The hot melt adhesive composition comprises: a base polymer, a tackifying resin, and an antioxidant, wherein: The base polymers include styrene block copolymers, amorphous α-olefin copolymers, and ethylene-vinyl acetate copolymers; The tackifying resin is a pure monomeric resin.

2. The hot melt adhesive composition according to claim 1, characterized in that, The hot melt adhesive composition comprises, by mass percentage: 30-60% base polymer, 35-70% tackifying resin, and 0-2% antioxidant, wherein the sum of the mass percentages of all components in the hot melt adhesive composition is 100%.

3. The hot melt adhesive composition according to claim 2, characterized in that, The hot melt adhesive composition comprises, by mass percentage: 32-42% base polymer, 37-67% tackifying resin and 1% antioxidant, wherein the sum of the mass percentages of all components in the hot melt adhesive composition is 100%.

4. The hot melt adhesive composition according to any one of claims 1 to 3, characterized in that, In the base polymer: The mass ratio of styrene block copolymer to amorphous α-olefin copolymer is 1:0.5 to 1:2, and the mass ratio of the sum of styrene block copolymer and amorphous α-olefin copolymer to ethylene-vinyl acetate copolymer is 1:0.5 to 1:

2.

5. The hot melt adhesive composition according to any one of claims 1 to 4, characterized in that, The base polymer also includes an ethylene-butyl acrylate copolymer.

6. The hot melt adhesive composition according to claim 5, characterized in that, The content of ethylene-butyl acrylate copolymer in the hot melt adhesive composition is 0-4%.

7. The hot melt adhesive composition according to any one of claims 1 to 6, characterized in that, The tackifying resin includes at least one of SA100, SA85, Y100, Y120, F100, and W100.

8. The hot melt adhesive composition according to any one of claims 1 to 6, characterized in that, The tackifying resin has a ring and ball softening point of 85-100℃.

9. The hot melt adhesive composition according to claim 8, characterized in that, The tackifying resin is W series products.

10. The hot melt adhesive composition according to any one of claims 1 to 9, characterized in that, The melt index of the styrene block copolymer is 27–220 g / 10 min.

11. The hot melt adhesive composition according to any one of claims 1 to 9, characterized in that, The melt viscosity of the amorphous α-olefin copolymer at 190°C is not greater than 3000 cps.

12. The hot melt adhesive composition according to any one of claims 1 to 11, characterized in that, The melt index of the ethylene-vinyl acetate copolymer is 400-800 g / 10 min.

13. The hot melt adhesive composition according to any one of claims 1 to 12, characterized in that, The VA content of the ethylene-vinyl acetate copolymer is ≥30%.

14. The hot melt adhesive composition according to any one of claims 1 to 13, characterized in that, The antioxidant is an inhibitory phenolic antioxidant.

15. A hot melt adhesive, characterized in that, The hot melt adhesive is mainly prepared from the hot melt adhesive composition according to any one of claims 1 to 14.

16. A method for preparing a hot melt adhesive according to claim 15, characterized in that, The preparation method includes: (A) The tackifying resin and antioxidant are mixed and melted to obtain mixture A; (B) After mixing the styrene block copolymer with mixture A, add the amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer, and optional ethylene-butyl acrylate copolymer in sequence, mix well, and obtain mixture B; (C) The mixture B is cooled, granulated and dried in sequence to obtain hot melt adhesive.

17. The method for preparing the hot melt adhesive according to claim 16, characterized in that, Step (B) is performed under vacuum conditions, with a vacuum level of -0.09 to -0.07 MPa.

18. The method for preparing the hot melt adhesive according to claim 17, characterized in that, Step (B) includes the following steps: After mixing the styrene block copolymer with mixture A, the mixture is stirred for 1 to 2 hours under the conditions of vacuum degree of -0.09 to -0.07 MPa, temperature of 120 to 130℃ and rotation speed of 80 to 100 r / min to completely melt the styrene block copolymer into the mixture. While maintaining the temperature at 120 to 130℃, amorphous α-olefin copolymer, ethylene-vinyl acetate copolymer and optionally ethylene-butyl acrylate copolymer are added in sequence, and the mixture is stirred under vacuum for another 1 to 2 hours to obtain mixture B.

19. The method for preparing the hot melt adhesive according to any one of claims 16 to 18, characterized in that, The cooling step (C) is carried out under vacuum conditions, with a vacuum degree of -0.09 to -0.07 MPa, and the temperature of mixture B after cooling is 90 to 100°C.

20. The use of a hot melt adhesive composition according to any one of claims 1 to 14 or the hot melt adhesive according to claim 6 in the preparation of industrially assembled or packaged adhesive products.

Images