阅读说明：本技术 一种耐电解液树脂组合物及应用其的胶水和胶带 (Electrolyte-resistant resin composition, and glue and adhesive tape using same ) 是由 丁越 谢彬 于 2021-08-20 设计创作，主要内容包括：本发明提供一种耐电解液树脂组合物,按照重量份数计算,包括以下组分：聚异丁烯120～140份、丁腈橡胶60～80份、丁基橡胶20～50份、反应性液态橡胶10～30份、固化剂1～1.5份；其中,固化剂包括多异氰酸酯类固化剂、氮丙啶类固化剂中的至少一种,反应性液态橡胶含有至少一个能与固化剂发生反应的官能基。在固化剂的作用下,反应性液态橡胶形成特殊的交联体系,能够对树脂组合物的极性和粘性都产生显著的调节作用,通过控制反应性液态橡胶的用量,能够使上述树脂组合物具有较高的极性和粘性,从而使得应用上述树脂组合物的胶水在极性基材上具有良好的铺展效果和粘接效果。(The invention provides an electrolyte-resistant resin composition which comprises the following components in parts by weight: 120-140 parts of polyisobutylene, 60-80 parts of nitrile rubber, 20-50 parts of butyl rubber, 10-30 parts of reactive liquid rubber and 1-1.5 parts of curing agent; the curing agent comprises at least one of polyisocyanate curing agent and aziridine curing agent, and the reactive liquid rubber contains at least one functional group capable of reacting with the curing agent. Under the action of a curing agent, the reactive liquid rubber forms a special crosslinking system, so that the polarity and viscosity of the resin composition can be remarkably adjusted, and the resin composition can have higher polarity and viscosity by controlling the using amount of the reactive liquid rubber, so that the glue applying the resin composition has good spreading effect and bonding effect on a polar substrate.)

1. An electrolyte-resistant resin composition is characterized by comprising the following components in parts by weight:

120-140 parts of polyisobutylene, 60-80 parts of nitrile rubber, 20-50 parts of butyl rubber, 10-30 parts of reactive liquid rubber and 1-1.5 parts of curing agent; wherein the curing agent comprises at least one of polyisocyanate curing agent and aziridine curing agent, and the reactive liquid rubber contains at least one functional group capable of reacting with the curing agent.

2. The electrolyte resistant resin composition of claim 1, wherein: the functional group of the reactive liquid rubber comprises at least one of carboxyl, hydroxyl and amino.

3. An electrolyte resistant resin composition as recited in claim 2, wherein: the reactive liquid rubber comprises at least one of functionalized polybutadiene and functionalized nitrile rubber.

4. An electrolyte resistant resin composition as recited in claim 3, wherein: the functionalized polybutadiene is hydroxyl-terminated polybutadiene, and the functionalized nitrile rubber is at least one selected from carboxyl-terminated nitrile rubber and amino-terminated nitrile rubber.

5. An electrolyte resistant resin composition as recited in claim 4, wherein: the curing agent is hexamethylene diisocyanate.

6. The electrolyte resistant resin composition of claim 1, wherein: the adhesive further comprises 30-50 parts of tackifying resin according to parts by weight, wherein the softening point of the tackifying resin is 80-150 ℃.

7. An electrolyte resistant resin composition as recited in claim 6, wherein: the tackifying resin is at least one of hydrogenated petroleum resin and hydrogenated terpene resin.

8. The glue is characterized by comprising the following components in parts by weight: an electrolyte-resistant resin composition according to any one of claims 1 to 7, comprising 210 to 360 parts by weight of an organic solvent and 300 to 600 parts by weight of an organic solvent.

9. The glue of claim 8, prepared by the following method:

dividing the organic solvent into two parts, mixing the reaction solution of the two parts with the reactive liquid rubber and the curing agent respectively to form a reaction solution A and a reaction solution B correspondingly, heating the reaction solution A until the temperature of the reaction solution A reaches 80-90 ℃, then adding the reaction solution B into the reaction solution A, and continuing to keep the temperature for 50-90 minutes after the addition is finished to obtain a mixture C;

and step two, adjusting the temperature of the mixture C to 20-40 ℃, adding the rest components contained in the resin composition into the mixture C, heating the obtained mixed solution until the temperature reaches 55-65 ℃, and preserving the heat for 20-30 hours to obtain a finished product.

10. An adhesive tape, comprising:

the base material is a polyethylene terephthalate film;

an adhesive layer applied to at least one surface of said substrate using said glue of claim 8, and then evaporating said organic solvent in said electrolyte-resistant glue to form said adhesive layer.

Technical Field

The invention belongs to the field of adhesives, and particularly relates to an electrolyte-resistant resin composition, and glue and an adhesive tape using the same.

Background

The lithium ion battery has the characteristics of high working voltage, high energy density, small self-discharge, repeated recycling, long service life, high environmental protection and the like, and is widely applied to the fields of mobile phones, automobiles, notebooks and the like. A large number of special tapes are used inside the lithium battery to improve the safety and stability of the battery, such as a termination tape, a double-sided hot-melt tape, a tail single-sided winding tape, and the like, and these tapes are located inside the battery, so that the battery has excellent electrolyte resistance.

The existing rubber type special adhesive tape coating base material for the lithium battery has larger limitation, and based on the excellent characteristics of a PET (polyethylene terephthalate) film, such as low water absorption rate, excellent oil resistance and solvent resistance, excellent impact resistance, good transparency, good dimensional stability to temperature and humidity, good electrical property, extremely wide use temperature range (-70 ℃ -150 ℃) and the like, the PET film becomes a base material widely applied to the rubber type special adhesive tape for the lithium battery at present. However, the conventional rubber-type adhesive has poor adhesion to polar substrates such as PET, and an adhesive tape prepared by coating the rubber-type adhesive on the surface of a PET film after soaking in an electrolyte has poor adhesion and is significantly degummed.

Disclosure of Invention

The invention aims to provide an electrolyte-resistant resin composition, and glue and adhesive tape using the same, so as to improve the bonding strength of an electrolyte-resistant adhesive for bonding a polar substrate.

According to a first aspect of the present invention, there is provided an electrolyte-resistant resin composition comprising, in parts by weight: 120-140 parts of polyisobutylene, 60-80 parts of nitrile rubber, 20-50 parts of butyl rubber, 10-30 parts of reactive liquid rubber and 1-1.5 parts of curing agent; the curing agent comprises at least one of polyisocyanate curing agent and aziridine curing agent, and the reactive liquid rubber contains at least one functional group capable of reacting with the curing agent.

Polyisobutylene and butyl rubber have good air tightness and chemical corrosion resistance, are suitable for being used as the main body resin of electrolyte-resistant glue, nitrile rubber contains strong polar groups, and can improve the polarity of the whole resin, therefore, in the electrolyte-resistant resin composition provided by the invention, polyisobutylene is used as the main body resin, reactive liquid rubber and a curing agent are introduced, the reactive liquid rubber forms a special crosslinking system, and special functional groups contained in the crosslinking system can generate obvious regulation effect on the polarity and viscosity of the resin composition, the adhesion effect of the resin on a base material is improved by improving the polarity of the resin and forming H bond adhesion with the surface of PET, and the dosage of the reactive liquid rubber is controlled within the range of the components of the electrolyte-resistant resin composition provided by the invention, so that the resin composition has higher polarity and viscosity, therefore, the glue applying the resin composition has good spreading effect and bonding effect on the polar substrate, and is characterized in that a glue layer formed by the glue can be closely compounded with the polar substrate, has excellent stripping resistance and non-degumming performance before and after the electrolyte is soaked, and shows excellent electrolyte resistance.

Preferably, the functionality of the polyisocyanate curing agent is 1 to 3, and the functionality of the aziridine curing agent is 1 to 3.

Preferably, the weight average molecular weight of the reactive liquid rubber is 1000 to 8000.

Preferably, the functional group of the reactive liquid rubber includes at least one of a carboxyl group, a hydroxyl group, and an amino group. On one hand, the reactive liquid rubber with the functional group has good crosslinking activity with the curing agent adopted by the invention, so that the reactive liquid rubber is converted into a crosslinking system at a high conversion rate, and on the other hand, the functional group of the reactive liquid rubber can react with a plurality of polar substrates, so that chemical bonding is established between the reactive liquid rubber or a crosslinking body obtained by conversion of the reactive liquid rubber and the polar substrates, and the peel strength of a rubber layer containing the resin composition and the polar substrates after the rubber layer and the polar substrates are compounded is further improved.

Preferably, the functionality of the reactive liquid rubber is 1 to 3.

Preferably, the reactive liquid rubber comprises at least one of functionalized polybutadiene, functionalized nitrile rubber. The reactive liquid rubber can not only generate a crosslinking reaction by itself under the action of a curing agent, but also can be crosslinked with other resins in the resin composition provided by the invention together to form a larger crosslinked network. Therefore, on one hand, the viscosity of the resin composition can be increased, and on the other hand, the compatibility of the reactive liquid resin and other materials in the resin composition is improved, so that the mediation effect of the reactive liquid rubber in the composite strength between the reinforcing rubber layer and the polar base material can be fully exerted.

Preferably, the functionalized polybutadiene is hydroxyl-terminated polybutadiene, and the functionalized nitrile rubber is at least one selected from carboxyl-terminated nitrile rubber and amino-terminated nitrile rubber.

Preferably, the hydroxyl value of the hydroxyl-terminated polybutadiene is 0.5-1.5.

Preferably, the acid value of the carboxyl-terminated butadiene-acrylonitrile rubber is 20-40.

Preferably, the amine value of the amino-terminated butadiene-acrylonitrile rubber is 20-150. More preferably, the amine value of the amino-terminated butadiene-acrylonitrile rubber is 30-47.

Preferably, the reactive liquid rubber comprises an amino terminated nitrile rubber.

Preferably, the curing agent is hexamethylene diisocyanate.

Preferably, the NCO content of the hexamethylene diisocyanate is 15-20.

Preferably, the polyisobutene comprises a polyisobutene component A with the weight-average molecular weight of 30 w-50 w and a polyisobutene component B with the weight-average molecular weight of 8 w-11 w, and the component mass ratio of the polyisobutene component A to the polyisobutene component B is 0.5-1.5: 1-3.

Preferably, the weight average molecular weight of the polyisobutene component A is 40w and the weight average molecular weight of the polyisobutene component B is 9.5 w.

The polyisobutylene component A with high weight average molecular weight has good electrolyte resistance, while the polyisobutylene component B with low weight average molecular weight has good bonding performance, and the polyisobutylene with different weight average molecular weights is matched, so that the resin composition provided by the invention has good bonding performance and electrolyte resistance by adjusting the proportion of the polyisobutylene component A and the polyisobutylene component B.

Preferably, the mass ratio of the components of the polyisobutene component A and the polyisobutene component B is 1: 2.

Preferably, the acrylonitrile-butadiene rubber has an acrylonitrile content of 10% to 30%. More preferably, the acrylonitrile-butadiene rubber has an acrylonitrile content of 18%.

Preferably, the Mooney viscosity of the nitrile rubber is 20-80. More preferably, the mooney viscosity of the nitrile rubber is 27.

Preferably, the Mooney viscosity of the butyl rubber is 20-80. More preferably, the mooney viscosity of the butyl rubber is 47.

Preferably, the adhesive further comprises 30-50 parts of tackifying resin by weight, and the softening point of the tackifying resin is 80-150 ℃.

Preferably, the tackifying resin is selected from at least one of hydrogenated petroleum resins, hydrogenated terpene resins.

Preferably, the hydrogenated petroleum resin is at least one selected from the group consisting of hydrogenated C5 resin, hydrogenated C9 resin, and hydrogenated terpene resin is hydrogenated DCPD resin.

According to a second aspect of the invention, the glue is provided, which comprises the following components in parts by weight: 210-360 parts of electrolyte-resistant resin composition and 300-600 parts of organic solvent.

Preferably, the organic solvent is selected from at least one of toluene, xylene and ethyl ester. Preferably, toluene is used as the organic solvent.

Preferably, the glue provided by the invention further comprises a pigment, and the amount of the pigment in the glue is not more than 25 parts by weight.

Preferably, the pigment comprises at least one of an inorganic pigment and an organic pigment, wherein the inorganic pigment is selected from at least one of cobalt blue, iron blue, cobalt green and chromium green, and the organic pigment is selected from at least one of titanium cyan and phthalocyanine green.

Preferably, the glue provided by the invention is prepared according to the following method: dividing an organic solvent into two parts, mixing reaction solutions of the two parts with reactive liquid rubber and a curing agent respectively to form a reaction solution A and a reaction solution B correspondingly, heating the reaction solution A until the temperature of the reaction solution A reaches 80-90 ℃, then adding the reaction solution B into the reaction solution A, and continuing to keep the temperature for 50-90 minutes after the addition is finished to obtain a mixture C; and step two, adjusting the temperature of the mixture C to 20-40 ℃, adding the residual components contained in the resin composition into the mixture C, heating the obtained mixed solution until the temperature reaches 55-65 ℃, and preserving the heat for 20-30 hours to obtain a finished product.

Preferably, in the step one, the reaction liquid B is added into the reaction liquid A in a dropwise adding manner, wherein the dropwise adding speed is 100-150 drops/min.

Preferably, the glue provided by the invention is prepared according to the following method:

dividing an organic solvent into two parts, mixing reaction solutions of the two parts with reactive liquid rubber and a curing agent respectively to form a reaction solution A and a reaction solution B correspondingly, heating the reaction solution A until the temperature of the reaction solution A reaches 85 ℃, stirring the reaction solution A at a speed of 100 revolutions per minute, after 10 minutes, increasing the stirring speed to 500 revolutions per minute, dropwise adding the reaction solution B into the reaction solution A at a speed of 120 drops per minute, continuing stirring and keeping the temperature for 60 minutes after the dropwise adding is finished, stopping heating to obtain a mixture C, testing the viscosity of the mixture C, and determining the reaction degree;

step two: and after the temperature of the mixture C is reduced to room temperature, sequentially adding the polyisobutylene, the nitrile rubber, the butyl rubber and the tackifying resin into the mixture C in weight percentage, sealing the reaction container after the mixture C is added, heating the reaction material formed by the mixture C to 60 ℃, preserving the heat, and stirring for 24 hours to obtain the glue.

According to the glue prepared by the method, the reactive liquid rubber is premixed before other rubbers are mixed, so that the conversion rate of converting the reactive liquid rubber into a crosslinking system can be improved, and the electrolyte resistance of the glue prepared by the method is remarkably improved.

In the actual production, according to the requirement, the third step is introduced into the preparation method of the glue provided by the invention, so that the pigment is added into the glue prepared after the second step is completed, the glue and the pigment are fully mixed, and the glue is colored.

According to a third aspect of the present invention, there is provided an adhesive tape comprising: the base material is a polyethylene terephthalate film; the adhesive layer is applied on at least one surface of the substrate by using the glue provided by the invention, and then the organic solvent in the electrolyte-resistant glue is volatilized to form the adhesive layer. The base material and the adhesive layer of the adhesive tape provided by the invention are tightly compounded, the adhesive tape is not adhesive, has excellent electrolyte resistance, and is basically not sol in the process of soaking electrolyte.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments.

Example 1

Table 1 illustrates the characteristics of some materials and their corresponding materials used for preparing glue in this embodiment.

TABLE 1 materials for glue formulation and their material characteristics

According to the technical scheme provided by the invention, 4 formulas for preparing the electrolyte glue are provided in the embodiment and are respectively marked as formula 1, formula 2, formula 3 and formula 4, and the specific formula components are respectively shown in tables 2-5.

Table 2 composition of components of formula 1

Table 3 composition of components of formula 2

Table 4 composition of components of formula 3

Table 5 composition of components of formula 4

Preparing materials required by each formula according to tables 2-5, and preparing electrolyte-resistant glue based on different formulas according to the following steps:

step one, adding reactive liquid rubber and part of organic solvent into a reaction kettle according to weight percentage to obtain reaction liquid A, heating the reaction liquid A to 85 ℃, stirring the reaction liquid A at the speed of 100 revolutions per minute, after 10 minutes, increasing the stirring speed to 500 revolutions per minute, uniformly mixing a curing agent and the rest of organic solvent to obtain reaction liquid B, dropwise adding the reaction liquid B into the reaction liquid A in the reaction kettle at the speed of 120 drops per minute, continuing stirring and preserving heat for 60 minutes after dropwise adding is finished, and stopping heating to obtain a mixture C;

cooling the reaction kettle until the mixture C in the reaction kettle is cooled to room temperature, sequentially adding the polyisobutylene, the nitrile rubber, the butyl rubber and the tackifying resin in weight percentage, sealing the reaction kettle after the mixture C is added, heating the obtained reaction material until the temperature reaches 60 ℃, and stirring for 24 hours;

and step three, stirring the glue stock and the pigment obtained in the step two for 15 minutes in a planetary stirrer according to the weight percentage ratio to obtain a glue finished product.

In the glue finished product prepared according to the above steps, the glue finished product corresponding to the formula 1 is glue A, the glue finished product corresponding to the formula 2 is glue B, the glue finished product corresponding to the formula 3 is glue C, and the glue finished product corresponding to the formula 4 is glue D.

Weighing the materials required by the formula 2 according to the amount, and preparing the glue according to the following steps:

sequentially dissolving polyisobutylene, nitrile rubber, butyl rubber, reactive liquid rubber, a curing agent and tackifying resin in an organic solvent at 60-75 ℃ to form uniform rubber material;

and step two, adding the pigment into the glue stock prepared in the step one to prepare a glue finished product, and marking the glue finished product as glue B #.

Glue A, glue B #, glue C and glue D prepared by the implementation method are respectively coated on the PET film by taking a single-sided release PET film with the thickness of 12 mu m as a base material, so as to prepare the electrolyte-resistant adhesive tape for the lithium battery. And (3) carrying out glue coating operation on a coating machine, adjusting equipment parameters, setting the coating speed to be 20-30 m/min, forming a dry glue layer with the thickness of 4 microns on the surface of the base material by reference to the tested glue, and rolling to obtain a finished adhesive tape.

Comparative example

The prior art CN108192532 provides a rubber glue, as a comparative embodiment, in this example, the glue is prepared by using the formula of the glue provided by the prior art, and the formula is shown in table 6.

Table 6 glue formulation provided by the prior art

According to the formulation provided in table 6, the glue was prepared according to the following steps:

sequentially dissolving polyisobutylene rubber, epoxidized polyisobutylene rubber, amino-terminated liquid nitrile rubber and hydrogenated DCPD resin in toluene at 60-75 ℃ to form uniform rubber material;

and step two, adding cobalt green into the glue material prepared in the step one to prepare a glue finished product.

The glue prepared by the implementation is coated on a PET film by taking a single-sided release PET film with the thickness of 12 mu m as a base material, so as to prepare the electrolyte-resistant adhesive tape for the lithium battery. And (3) carrying out glue coating operation on a coating machine, adjusting equipment parameters, setting the coating speed to be 20-30 m/min, forming a dry glue layer with the thickness of 4 microns on the surface of the base material by reference to the tested glue, and rolling to obtain a finished adhesive tape.

Test example

1. Experimental construction mode

Using the tapes obtained in example 1 and comparative example, tape property tests were conducted.

(1) Peel force test

The peel strength test is carried out according to the method described in the national standard GB/T2792-2014.

(2) Post-soaking peel strength test

The electrolyte comprises the following components in percentage by mass: EC/PC/DEC/EP 30/10/30/30, 1M LiPF₆The test tapes provided in example 1 and comparative example were attached to aluminum foil at a lithium salt mass ratio of 12.5%, rolled back and forth 3 times with a 2kg roller, soaked at 85 ℃ for 24h (tape to electrolyte mass ratio 1:50), cooled to room temperature, and peel strength tested according to the method described in national standard GB/T2792-2014.

(3) Adhesion test

The back surfaces of the adhesive tapes provided in example 1 and comparative example were fixed to a steel plate with a double-sided adhesive tape, the adhesive surface faced upward, after fixing, the adhesive tape of the corresponding formulation was stuck to the adhesive surface of the adhesive tape on the steel plate, and the adhesive tape was rolled back and forth 3 times at 300mm/min using a 2kg press roll, peeled off at 180 degrees at 300mm/min using a tensile machine, and the condition of the adhesive layer was observed.

2. Results of the experiment

The results obtained after the above-described performance measurement were carried out on the test tapes of this example are shown in Table 7. The test tape is carried by the test belt to carry out an electrolyte soaking experiment, after the electrolyte is soaked, the peel strength of the test tape provided by the comparative example is greatly reduced, and the corresponding retention rate is obviously lower than that of other test tapes, so that the adhesive tape prepared in the example 1 has more excellent electrolyte resistance compared with the test tape provided by the comparative example. On the other hand, the results of the opposite adhesion experiment show that the adhesive tape provided in example 1 can still maintain the adhesive surface intact after the opposite adhesion experiment, thereby proving that the glue prepared in example 1 can form a stable composite structure with the PET film as the substrate. The adhesive tape provided in the comparative example has a condition that the adhesive layer is obviously transferred after the double-stick test, that is, the adhesive tape cannot pass the qualification marking of the double-stick test, thereby indicating that the composite strength between the adhesive layer and the substrate is low. Finally, it is noted that: by comparing the reference adhesive tapes prepared respectively corresponding to the glue B and the glue C, the adhesive tape prepared by the corresponding glue B can still keep higher adhesive tape retention rate after being soaked in electrolyte, and the difference between the two formulas of the glue B and the glue C is only that the curing agent types selected by the glue B and the glue C are different, so that the matching between the curing agent type and the reactive liquid rubber type can obviously optimize the electrolyte resistance of the glue prepared by the glue B. In the glue formula provided by the embodiment, the amino-terminated butadiene-acrylonitrile rubber is adopted as the reactive resin, and the liquid HDI is adopted as the curing agent, so that the prepared glue has electrolyte resistance obviously superior to that of other various formulas. Finally, by comparing various performance indexes of the adhesive tape respectively made of the glue B and the glue B #, the adhesive tape made of the glue B can be found to have excellent electrolyte resistance, after the adhesive tape is soaked in electrolyte, the retention rate of the glue layer is far higher than that of other reference adhesive tapes, and the glue B # still has the condition of degumming in a double-adhesion test.

TABLE 7 characterization of adhesive tape properties of the reference objects used in the test examples

Although the present invention has been described in detail with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the true spirit and scope of the present invention.