JP2015061900A - Composition, separator for lithium secondary battery, solid electrolyte for lithium secondary battery, and polyethylene product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition that can solve problems caused by characteristics of polyethylene, and a separator for a lithium secondary battery, a solid electrolyte for a lithium secondary battery, and a polyethylene product.SOLUTION: The composition comprises a block copolymer containing a first monomer having a side chain of an alkane chain and a second monomer having (a) a side chain of a polyoxyethylene structure or (b) a substituent having a tertiary amine structure, and the composition is to be adsorbed to a surface of polyethylene. The separator for a lithium secondary battery includes a polyethylene porous film, the above composition filling the polyethylene porous film, and a lithium ion carried by the polyethylene porous film.

Description

  The present invention relates to a composition intended to be adsorbed on the surface of polyethylene, a separator for a lithium secondary battery, a solid electrolyte for a lithium secondary battery, and a polyethylene product.

  Polyethylene is a polymer material that is widely used, and has characteristics such as high crystallinity and excellent solvent resistance (see Patent Document 1).

JP 2012-144723 A

  On the other hand, because of the above characteristics, polyethylene may be difficult to use as it is depending on the application. This invention is made | formed in view of the above point, and it aims at providing the composition which can solve said subject, the separator for lithium secondary batteries, the solid electrolyte for lithium secondary batteries, and a polyethylene product.

  The composition of the present invention comprises a first monomer having a side chain of an alkane chain, and (a) a second monomer having a side chain having a polyoxyethylene structure or (b) a substituent having a tertiary amine structure. It contains a block copolymer and is used for adsorption onto the surface of polyethylene.

  The composition of the present invention can be used for, for example, filling a polyethylene porous membrane and producing a separator for a lithium secondary battery. This lithium secondary battery separator has high conductivity. In addition, this lithium secondary battery separator can lower the conductivity before the temperature range where the lithium secondary battery causes thermal runaway (the lithium secondary battery itself has an intelligent effect of self-control). .

Furthermore, even if the conductivity of the lithium secondary battery separator once decreases due to the temperature rise, if the temperature is subsequently decreased, the separator again has a high conductivity.
Moreover, the composition of this invention can be used for the use which fills a polyethylene porous membrane and manufactures the solid electrolyte for lithium secondary batteries, for example. This solid electrolyte for a lithium secondary battery has high conductivity. In addition, this solid electrolyte for a lithium secondary battery reduces conductivity before reaching a temperature range where the lithium secondary battery causes thermal runaway (the lithium secondary battery itself has an intelligent effect of self-control). it can.

  Moreover, the composition of this invention can be used for the use which modifies the surface of at least one part in the base material which consists of polyethylene, for example, and manufactures a polyethylene product. This polyethylene product can be firmly bonded with an epoxy resin-based adhesive or other general adhesive (for example, Aron Alpha (registered trademark), etc.). In addition, this polyethylene product can be easily peeled off if it is heated after being bonded with an epoxy resin adhesive or other general adhesive.

It is explanatory drawing showing the structure of composition S3. FIG. 2A is a plan view showing the test piece 1, and FIG. 2B is an explanatory view showing a state in which two test pieces are bonded. It is explanatory drawing showing the structure of composition S4.

  An embodiment of the present invention will be described. The composition of the present invention comprises a block copolymer comprising a first monomer and a second monomer. The first monomer has a main chain and an alkane chain side chain. The side chain of the first monomer preferably has a length having 10 or more carbon atoms. In this case, the adsorption strength with respect to the polyethylene surface is further improved, and the transition temperature is further increased.

  The structure of the main chain in the first monomer is not particularly limited. The first monomer can be, for example, a vinyl monomer. In this case, a block copolymer can be produced by living polymerization.

Examples of the first monomer include the following. Behenyl acrylate (CH ₂ = CH (CO) O (CH ₂ ) ₂₁ CH ₃ ), stearyl acrylate (CH ₂ = CH (CO) O (CH ₂ ) ₁₇ CH ₃ ), lauroyl acrylate (CH ₂ = CH (CO) O (CH ₂ ) ₁₁ CH ₃ ).

The second monomer may have a main chain and a side chain having a polyoxyethylene structure, or may have a main chain and a substituent having a tertiary amine structure.
The polyoxyethylene structure is a structure represented by “— (CH ₂ —CH ₂ —O—) _n —”, and the value of n is 2 or more. The substituent having a tertiary amine structure is a substituent having a structure represented by “—N (R1) (R2)”, and R1 and R2 are each independently H or a hydrocarbon. Carbon number in this hydrocarbon can be 1-3, for example.

  The structure of the main chain in the second monomer is not particularly limited. The second monomer can be, for example, a vinyl monomer. In this case, a block copolymer can be produced by living polymerization.

Examples of the second monomer having a main chain and a side chain of a polyoxyethylene structure include the following. Di (ethylene glycol) ethyl ether acrylate _{(CH 2 = CH (CO)} O (CH 2 -CH 2 -O-) 2 C 2 H 5), polyethylene glycol - monoacrylate _{(CH 2 = CH (CO)} O (CH _{2 -CH 2 -O-) n H)} (n = 2~10), methoxy - polyethylene glycol - acrylate _{(CH 2 = CH (CO)} O (CH 2 -CH 2 -O-) n CH 3) (n = 2-9), and one or more selected from the group consisting of methacrylates or acrylates having polar groups such as amide groups and hydroxyl groups at the side chain sites.

  Examples of the second monomer having a main chain and a substituent having a tertiary amine structure include the following. 2- (Dimethylamino) ethyl methacrylate (2-EMA), 2- (Diethylamino) ethyl methacrylate (DEAEMA), 2- (tert-butylamino) ethyl methacrylate ( 2- (tert-Butylamino) ethyl Methacrylate (TBAEMA), N, N-dimethylacrylamide (N, N-Dimethylacrylamide, DMAA), N, N-dimethylaminopropyl acrylamide (N, N-Dimethylaminopropyl Acrylamide, DMAPAA), and N One or more selected from the group consisting of N-diethylacrylamide (DEAA).

  In the block copolymer, the molecular weight corresponding to the first monomer and the molecular weight corresponding to the second monomer are each preferably 500 or more (preferably 1000 or more). When the molecular weight corresponding to the first monomer is 500 or more, the adhesiveness to polyethylene is excellent. Further, when the molecular weight corresponding to the second monomer is 500 or more, the surface of polyethylene can be modified to have arbitrary characteristics. The block copolymer may be composed of a first monomer and a second monomer, and may further contain other monomers.

  If the composition of the present invention is adsorbed on the surface of polyethylene, the surface of the polyethylene can be made hydrophilic. Moreover, if the composition of this invention is made to adsorb | suck to the surface of polyethylene, the adhesive strength when the polyethylene is adhere | attached with an adhesive agent can be raised.

  The separator for a lithium secondary battery of the present invention and the solid electrolyte for a lithium secondary battery of the present invention are supported on a polyethylene porous film, the composition filled in the polyethylene porous film, and the polyethylene porous film. Lithium ion. The said composition can be made to adsorb | suck in the pore in a polyethylene porous membrane, for example.

  As a polyethylene porous membrane, the well-known thing utilized as a separator for lithium secondary batteries can be widely used, for example. One example is Mykrolis (registered trademark) UPE (pore size is 0.1 μm, 0.01 μm) (NIHON ENTEGRIS KK YONEZAWA, JAPAN). The polyethylene porous membrane preferably has an average pore size of 0.01 μm or more. This is excellent in terms of lithium ion conductivity.

  As a method of filling the polyethylene porous membrane with the composition, for example, the composition is heated to the melting point or higher with a hot plate or the like, and the molten composition is filled into the polyethylene porous membrane by gravity or by pressing. There is a way. As another method, there is a method in which a solution is prepared by dissolving the composition in a solvent, and a polyethylene porous membrane is immersed in the solution.

  As a method for supporting lithium ions on the polyethylene porous membrane, for example, a lithium salt is dissolved at a concentration of 1 mol / L in a volatile electrolyte solution (for example, dimethylacetamide (DMAC), acrylonitrile, etc.) that can dissolve the lithium salt. And a method of immersing a polyethylene porous membrane in this solution.

  With the composition of the present invention, for example, at least a part of the surface of a substrate made of polyethylene can be modified. As a method for modifying the surface of the substrate with the composition, for example, a solution is prepared by dissolving the composition in a volatile solvent, and the substrate is immersed in the solution, or the solution is applied to the surface of the substrate. The method of doing is mentioned. The concentration of the composition in the solution used in this method is preferably 10 wt% or less, and more preferably 5 wt% or less.

The shape of the base material made of polyethylene is not particularly limited, and examples thereof include a plate-like member, a rod-like member, a cylindrical member, a spherical member, and a rectangular parallelepiped member. Moreover, the whole base material may consist of polyethylene, and may consist of the core material which consists of materials other than polyethylene, and the polyethylene layer which coat | covers at least one part.
Example 1
1. Production of Composition S1 Composition S1 was produced by the following procedure.
(I) 3.0 g of butyl acetate and 4.0 g of di (ethylene glycol) ethyl ether acrylate (DEEA) were placed in a three-necked flask.
(Ii) As an initiator, 3,7-Dioxa-4-aza-6-phosphanonanoic acid, 4,5-bis (1,1-dimethylethyl) -6-ethoxy-2,2-dimethyl-, 6-oxide ( SG-1-MA (BlocBuilder @ARKEMA)) was placed in a three-necked flask in an amount of 0.29 g, the temperature was set to 105 ° C., and polymerization was performed for 4 hours.
(Iii) 4 hours after the start of polymerization, 4.9 g of butyl acetate and 5.8 g of stearyl acrylate (STA) were added to and charged into a three-necked flask, and polymerization was performed for 4 hours. Thereafter, the temperature was lowered to complete the polymerization.

Through the steps (i) to (iii), a block copolymer (composition S1) composed of 9500 g / mol DEEA and 4900 g / mol STA was obtained.
2. Production of lithium secondary battery separator A lithium secondary battery separator was produced by the following procedure. The composition S1 produced as described above was added to xylene and stirred to prepare a xylene solution of the composition S1. The concentration of the composition S1 in this solution was 0.5 wt%.

  The polyethylene porous membrane was immersed in this solution for 4 hours. Mykrolis UPE (pore size is 0.1 μm, 0.01 μm) was used as the polyethylene porous membrane. Thereafter, the polyethylene porous membrane was taken out of the solution and air-dried. The polyethylene porous membrane was filled with the composition S1 through the steps so far.

  Next, 1.519 g of Lithium hexafluorosphate was added to 10 g of DMAC to prepare a lithium ion solution. In this lithium ion solution, the polyethylene porous film after filling the composition S1 as described above was immersed for 2 hours, and lithium ions were supported on the polyethylene porous film. Through the above steps, a separator for a lithium secondary battery could be manufactured.

3. Evaluation of Lithium Secondary Battery Separator (3-1) Conductivity Evaluation The conductivity of a lithium secondary battery separator was measured by an impedance measurement method. The measurement conditions were as follows.

Measuring device: LCR-HITESTER (HIOKI 3522-50)
Measurement range: 50-80000Hz, 34points
How to determine conductivity: By Cole-Cole plot
Measurement temperature: 35, 40, 45, 45, 50, 55, 60, 65 ° C
The conductivity value was 9.08 × 10 ⁻⁵ S / cm at 35 ° C., and it was confirmed that the material had high ionic conductivity.

  The reason why the lithium secondary battery separator has high ionic conductivity can be estimated as follows. The long side chain alkane chain has good adsorption properties with polyethylene, so this part of the block copolymer is adsorbed on the side of the polyethylene porous structure, and the polyoxyethylene chain forms a phase along the side of the porous structure It becomes possible to do. Because of this structure, a structure in which the polymer solid electrolyte is oriented in the direction of both the positive and negative electrodes is formed. The side chain polyoxyethylene does not cause crystallization because of its short molecular chain length, and maintains a very motility structure. As a result, it is considered that the lithium ion conductivity that has been difficult to obtain in the solid state has been developed.

The conductivity value at 65 ° C. was 8.30 × 10 ⁻⁵ S / cm, which was much lower than the conductivity at 35 ° C. This is because the block copolymer constituting the composition S1 is detached from the pore surface of the polyethylene porous membrane by the temperature rise, thereby destroying the continuous layer of the polyoxyethylene component having a lithium ion conduction function. It can be inferred that this is due to disappearance.

  If the separator for a lithium secondary battery of this example is used, the conductivity decreases rapidly before reaching the temperature range where the lithium secondary battery causes thermal runaway due to the property that the conductivity decreases at high temperatures (lithium 2 The secondary battery itself has an intelligent effect of self-control).

Further, even if the conductivity once decreases due to the temperature rise, the conductivity increases again if the temperature of the lithium secondary battery separator is decreased. It can be presumed that this is because the block copolymer is re-adsorbed and rearranged due to a decrease in temperature, and a continuous layer of polyoxyethylene component having a lithium ion conduction function is formed again. With this function, the lithium secondary battery separator of this embodiment can be reused even after the lithium secondary battery has caused thermal runaway.
(Example 2)
1. Production of Composition S2 Composition S2 was produced by the following procedure.
(I) 7.7 g of butyl acetate and 4.9 g of behenyl acrylate (BHA) were placed in a three-necked flask.
(Ii) As an initiator, 3,7-Dioxa-4-aza-6-phosphanonanoic acid, 4,5-bis (1,1-dimethylethyl) -6-ethoxy-2,2-dimethyl-, 6-oxide ( SG-1-MA (BlocBuilder @ARKEMA)) was placed in a three-necked flask in an amount of 0.29 g, the temperature was set at 105 ° C., and polymerization was performed for 6 hours.
(Iii) Six hours after the start of polymerization, 33.6 g of butyl acetate and 22.4 g of polyethylene glycol-monoacrylate (AE-400) were added and charged into a three-necked flask, and polymerization was performed for 62 hours. Thereafter, the temperature was lowered to complete the polymerization.

Through the steps (i) to (iii), a block copolymer (composition S2) composed of 3000 g / mol BHA and 62000 g / mol AE-400 could be obtained.
2. Production of polyethylene product P1 A polyethylene film (an example of a base material made of polyethylene) was prepared. This polyethylene film is obtained by press-molding commercially available HDPE pellets (Nipolon Hard 4200 manufactured by Tosoh Corporation) to a thickness of 100 μm at 180 ° C. and 20 MPa.

  On the other hand, 0.5 g of the composition S2 was dissolved in 50 g of butyl acetate to prepare a butyl acetate solution of the composition S2. A polyethylene film was immersed in this solution and then taken out. A layer of composition S2 was formed on the surface of the polyethylene film. That is, the surface of the polyethylene film was modified with the composition S2. When observed by TEM, the film thickness of the composition S2 was about 200 nm. The polyethylene product P1 provided with the polyethylene film and composition S2 which modifies the surface was able to be manufactured according to the above process.

3. Evaluation of Composition S2 (3-1) Evaluation of Adhesive Strength Two test pieces 1 (see FIG. 2A) having a shape defined by JIS K71132 (1/3) were cut out from the polyethylene film. About each test piece 1, the part 5 from the edge 2 of one side to the position 3 of 30.5 mm was left, and the other part 7 was excised.

  In one test piece 1, a portion corresponding to 26.5 to 30.5 mm from the one end 2 (hereinafter referred to as an adhesive portion 5A) was immersed in a butyl acetate solution of the composition S2, and then taken out. . As a result, the surface of the adhesive portion 5A was modified with the composition S2. The bonding portion 5A is a rectangular region having a width of 2 mm and a length of 5 mm. Moreover, also about the other test piece 1, the surface of the adhesion part 5A was similarly modified with composition S2.

  Next, as shown in FIG. 2B, an adhesive (epoxy resin-based cemedine EP001N) is applied to the adhesive part 5A of one test piece 1, and then the adhesive part 5A of one test piece 1 and the other test piece 1 adhesive part 5A was piled up and both were adhere | attached.

Hereinafter, a test piece SP1 is obtained by bonding two test pieces 1 together. The total length of the test piece SP1 is 57 mm.
Moreover, although it produces by the method similar to test piece SP1 fundamentally, instead of immersing a test piece in the butyl acetate solution of composition S2, what wash | cleaned the surface of the test piece with the solvent is called test piece SP2. did.

Moreover, although it created fundamentally by the method similar to test piece SP1, what omitted the process of immersing a test piece in the butyl acetate solution of composition S2 was made into test piece SP3.
About each of test piece SP1, SP2, SP3, it extended | stretched at the speed | rate of 1 mm / min using the expansion | extension test machine, and the expansion | extension characteristic was measured. The measurement results are shown in Table 1. Here, the Young's modulus is calculated from the rate of change of the force with respect to the elongation immediately after the elongation measurement. The yield point is obtained from the maximum force in the extension test. The elongation at break is obtained from the elongation until the point at which the test piece breaks and the force required for the elongation becomes zero.

上記表１に示す評価結果から、ポリエチレン製品Ｐ１は、表面を組成物Ｓ２で修飾されていることで、エポキシ樹脂系の接着剤により強固に接着できることが確認できた。
（３−２）高温下での剥離性の評価
試験片ＳＰ１を７０℃の温水に浸漬したところ、短時間で接着面が剥離した。これは、接着剤の変化のためではなく、ポリエチレンフィルムの表面から、組成物Ｓ２を構成するブロック共重合体が外れたためであると推測できる。

From the evaluation results shown in Table 1 above, it was confirmed that the polyethylene product P1 can be firmly bonded with an epoxy resin adhesive by modifying the surface with the composition S2.
(3-2) Evaluation of peelability at high temperature When the test piece SP1 was immersed in warm water at 70 ° C., the adhesive surface peeled off in a short time. This can be presumed to be because the block copolymer constituting the composition S2 was removed from the surface of the polyethylene film, not because of a change in the adhesive.

Moreover, after the adhesion surface peeled as described above, the surface of the test piece was modified again with the composition S2, and then adhered with an epoxy resin adhesive, whereby strong adhesion performance was obtained.
(3-3) Measurement of contact angle About polyethylene product P1, the contact angle of the surface was measured using the water contact angle measuring apparatus. Moreover, the contact angle of the surface was similarly measured about the untreated polyethylene film and the polyethylene film wash | cleaned with the butyl acetate instead of using the butyl acetate dispersion liquid of composition S2 as a comparative example. The results are shown in Table 2.

表２に示すように、ポリエチレン製品Ｐ１の表面は、無処理のポリエチレンフィルム、及び酢酸ブチルで洗浄したポリエチレンフィルムの表面に比べ、親水性であった。
（実施例３）
１．リチウム２次電池用固体電解質の製造
市販のリチウム２次電池用セパレータ（厚さ３０μｍ、空孔率６４％、ガーレー値７８sec/100cc）を用意した。以下ではこれを市販セパレータとする。この市販セパレータは、ポリエチレン多孔質膜の一例である。市販セパレータを、組成物Ｓ２の０．５ｗｔ％アセトニトリル溶液に浸漬した。このとき、市販セパレータの空孔に組成物Ｓ２が充填された。

As shown in Table 2, the surface of the polyethylene product P1 was more hydrophilic than the untreated polyethylene film and the surface of the polyethylene film washed with butyl acetate.
(Example 3)
1. Production of Solid Electrolyte for Lithium Secondary Battery A commercially available separator for lithium secondary battery (thickness 30 μm, porosity 64%, Gurley value 78 sec / 100 cc) was prepared. Hereinafter, this is a commercially available separator. This commercially available separator is an example of a polyethylene porous membrane. A commercially available separator was immersed in a 0.5 wt% acetonitrile solution of composition S2. At this time, the composition S2 was filled in the pores of the commercial separator.

  Next, the commercial separator after filling with the composition S2 was immersed in a lithium hexafluorophosphate solution having a concentration of 1 mol / l, and lithium ions were introduced. Lithium ions were supported on a commercial separator. Through the above steps, a solid electrolyte for a lithium secondary battery could be manufactured.

2. Evaluation of solid electrolyte for lithium secondary battery The characteristics of the solid electrolyte for lithium secondary battery produced as described above were evaluated by impedance measurement. As a result, the lithium ion conductivity at 35 ° C. was 4.47 × 10 ⁻⁴ S / cm, which was very good as a solid electrolyte for a lithium secondary battery. On the other hand, at 70 ° C., the lithium ion conductivity decreased to 1.58 × 10 ⁻⁴ S / cm. From this, it was confirmed that the output of the solid electrolyte for lithium secondary battery of this embodiment can be controlled by temperature.
Example 4
1. Production of Composition S3 A dispersion in which 5.0 g of behenyl acrylate (BHA) was dispersed in 7.7 g of butyl acetate was charged into a stirring polymerization apparatus and polymerized for 6 hours in a nitrogen stream while heating in an oil bath (105 ° C.). . At this time, the stirring speed in the stirring polymerization apparatus was about 70 rpm.

  Next, 4.2 g of 2- (diethylamino) ethyl methacrylate (DEAEMA) dispersed in 4.1 g of butyl acetate was put into the same stirring polymerization apparatus and heated in an oil bath (105 ° C.) under a nitrogen stream. Polymerized for 17 hours. Also at this time, the stirring speed in the stirring polymerization apparatus was about 70 rpm.

  Through the above steps (living radical polymerization), a block copolymer (composition S3) composed of 2400 g / mol of BHA and 25600 g / mol of DEAEMA could be obtained. The composition S3 has a structure shown in FIG. In FIG. 1, n and m are integers.

The polydispersity (M _w / M _n ) of the composition S3 is 1.18.
2. Evaluation of Composition S3 (2-1) Evaluation of Adhesive Strength In the same manner as in Example 2, the adhesive portion 5A of the two test pieces 1 was modified with the composition S3, and then the two test pieces 1 were used. The adhering portions 5A were bonded with an adhesive (see FIGS. 2A and 2B). Below, what adhered two test pieces 1 is used as a post-adhesion test piece.

  The step of modifying the surface of the adhesion part 5A with the composition S3 was performed by a dip coating method using a butyl acetate dispersion (concentration 1 wt%) of the composition S3. As the adhesive, an epoxy resin adhesive or Aron Alpha was used.

  Next, using a tensile tester, the test piece after adhesion was pulled at a speed of 1 mm / min in the direction in which the two test pieces 1 were separated. The elongation at break was recorded. The test was performed 6 times, and the average value of 6 tests was adopted. It means that the force which adhere | attaches the two test pieces 1 is so strong that the value of breaking elongation is large.

  As a comparative example, acetic acid is used instead of the step of adsorbing the composition S3 on the surfaces of the two test pieces 1 (unmodified) and the step of adsorbing the composition S3 on the surfaces of the two test pieces 1 In the case where the step of washing with butyl was performed, the elongation at break was measured in the same manner. The test results are shown in Table 3.

なお、表３において、ＳＰ４〜ＳＰ９はそれぞれ以下の条件を意味する。

In Table 3, SP4 to SP9 mean the following conditions, respectively.

  SP4: The surface of the test piece 1 is modified with the composition S3 by a dip coating method using a butyl acetate dispersion (concentration 1 wt%) of the composition S3. The adhesive is an epoxy resin adhesive.

SP5: The test piece 1 is washed with butyl acetate. The adhesive is an epoxy resin adhesive.
SP6: The test piece 1 is unmodified. The adhesive is an epoxy resin adhesive.
SP7: The surface of the test piece 1 is modified with the composition S3 by dip coating using a butyl acetate dispersion (concentration 1 wt%) of the composition S3. The adhesive is Aron Alpha.

SP8: The test piece 1 is washed with butyl acetate. The adhesive is Aron Alpha.
SP9: The test piece 1 is unmodified. The adhesive is Aron Alpha.
As shown in Table 3, regardless of the type of adhesive, when the composition S3 was adsorbed on the surfaces of the adhesive portions 5A of the two test pieces 1, the elongation at break was larger than in other cases ( The adhesive strength between the two test pieces 1 was great).

(2-2) Measurement of contact angle Butyl acetate was added to composition S3 to prepare a butyl acetate dispersion of composition S3. The concentration of the composition S3 in this dispersion was 1 wt%.

  The composition S3 was adsorbed on the surface of a polyethylene film having a thickness of 150 μm by the dip coating method using the above dispersion. The polyethylene film having the composition S3 adsorbed on the surface is hereinafter referred to as a polyethylene product P2.

  About polyethylene product P2, the contact angle of the surface was measured using the water contact angle measuring apparatus. Moreover, the contact angle of the surface was similarly measured about the untreated polyethylene film and the polyethylene film wash | cleaned with the butyl acetate instead of using the butyl acetate dispersion liquid of composition S3 as a comparative example.

  The results are shown in Table 4.

表４に示すように、ポリエチレン製品Ｐ２の表面は、無処理のポリエチレンフィルムの表面、及び酢酸ブチルで洗浄したポリエチレンフィルムの表面に比べ、接触角が小さく、親水性であった。
（実施例５）
１．組成物Ｓ４の製造
ベヘニルアクリレート（ＢＨＡ）４．８ｇを酢酸ブチル７．８ｇに分散したものを撹拌重合装置に投入し、オイルバス（１０５℃）で加熱しながら、窒素気流下で２４時間重合した。このとき、撹拌重合装置における攪拌速度は７０ｒｐｍ前後とした。

As shown in Table 4, the surface of the polyethylene product P2 had a smaller contact angle and was hydrophilic compared to the surface of the untreated polyethylene film and the surface of the polyethylene film washed with butyl acetate.
(Example 5)
1. Production of Composition S4 A dispersion in which 4.8 g of behenyl acrylate (BHA) was dispersed in 7.8 g of butyl acetate was put into a stirring polymerization apparatus and polymerized for 24 hours in a nitrogen stream while heating in an oil bath (105 ° C.). . At this time, the stirring speed in the stirring polymerization apparatus was about 70 rpm.

  Next, a dispersion of 5.1 g of 2- (tert-butylamino) ethyl methacrylate (TBAEMA) in 7.7 g of butyl acetate was put into the same stirring polymerization apparatus and heated in an oil bath (105 ° C.) while being heated with nitrogen. Polymerization was performed for 6 hours under an air stream. Also at this time, the stirring speed in the stirring polymerization apparatus was about 70 rpm.

  Through the above process (living radical polymerization), a block copolymer (composition S4) composed of 1700 g / mol of BHA and 7600 g / mol of TBAEMA could be obtained. The composition S4 has a structure shown in FIG. In FIG. 3, n and m are integers.

The polydispersity (M _w / M _n ) of the composition S4 is 1.21.
2. Evaluation of Composition S4 (2-1) Evaluation of Adhesive Strength In the same manner as in Example 2, the adhesive portion 5A of the two test pieces 1 was modified with the composition S4, and then the two test pieces 1 were used. The adhesive portions 5A were bonded to each other with an adhesive (see FIGS. 2A and 2B) to prepare a test piece after bonding.

  The step of modifying the surface of the adhesive portion 5A with the composition S4 was performed by a film applicator method using a butyl acetate dispersion (concentration 0.05 wt% or 0.1 wt%) of the composition S4. Moreover, Aron Alpha was used for the adhesive.

  Next, using a tensile tester, the test piece after adhesion was pulled at a speed of 1 mm / min in the direction in which the two test pieces 1 were separated. The elongation at break was recorded. The test was performed 6 times, and the average value of 6 tests was adopted. It means that the force which adhere | attaches the two test pieces 1 is so strong that the value of breaking elongation is large.

  As a comparative example, when the step of adsorbing the composition S4 on the surfaces of the two test pieces 1 is omitted, and the step of washing with butyl acetate instead of the step of adsorbing the composition S4 on the surfaces of the two test pieces 1 In the case where the test was performed, the elongation at break was measured in the same manner.

  Table 5 shows the measurement results.

なお、表５において、ＳＰ１０〜ＳＰ１３はそれぞれ以下の条件を意味する。

In Table 5, SP10 to SP13 mean the following conditions, respectively.

  SP10: The surface of the test piece 1 is modified with the composition S4 by a film applicator method using a butyl acetate dispersion (concentration 0.05 wt%) of the composition S4. The adhesive is Aron Alpha.

  SP11: The surface of the test piece 1 is modified with the composition S4 by a film applicator method using a butyl acetate dispersion (concentration: 0.1 wt%) of the composition S4. The adhesive is Aron Alpha.

SP12: The test piece 1 is washed with butyl acetate. The adhesive is Aron Alpha.
SP13: The test piece 1 is unmodified. The adhesive is Aron Alpha.
As shown in Table 5, when the composition S4 was adsorbed on the surfaces of the two test pieces 1, the elongation at break was larger than in other cases (the adhesive force between the two test pieces 1 was large). ).
(2-2) Measurement of contact angle Butyl acetate was added to composition S4, and a butyl acetate dispersion of composition S4 having a concentration of composition S4 of 0.05 wt% and a concentration of composition S4 of 0.1 wt% And a butyl acetate dispersion of composition S4.

  The composition S4 was adsorbed on the surface of a polyethylene film having a thickness of 150 μm by the dip coating method or the film applicator coating method using the above dispersion. The polyethylene film having the composition S4 adsorbed on the surface has four types shown in Table 6 depending on the concentration of the composition S4 in the dispersion and the type of coating method, and the names thereof are polyethylene products P3 to P6, respectively. To do.

なお、表６において「分散液濃度」は、組成物Ｓ４の酢酸ブチル分散液における組成物Ｓ４の濃度を意味する。また、「Ｄ」はディップコーティング法を意味し、「Ｆ」はフィルムアプリケータコーティング法を意味する。

In Table 6, “dispersion concentration” means the concentration of the composition S4 in the butyl acetate dispersion of the composition S4. “D” means a dip coating method, and “F” means a film applicator coating method.

  About polyethylene products P3-P6, the contact angle of the surface was measured using the water contact angle measuring apparatus. In addition, as a comparative example, the surface contact angle was measured in the same manner for a non-treated polyethylene film and a polyethylene film washed with butyl acetate instead of using the butyl acetate dispersion of composition S4. The results are shown in Table 6 above.

  As shown in Table 6, the surface of the polyethylene products P3 to P6 was more hydrophilic than the surface of the untreated polyethylene film and the surface of the polyethylene film washed with butyl acetate.

  In addition, this invention is not limited to the said embodiment at all, and it cannot be overemphasized that it can implement with a various aspect in the range which does not deviate from this invention.

DESCRIPTION OF SYMBOLS 1 ... Test piece, 2 ... One end, 3 ... Cutting line, 5, 7 ... Part, 5A ... Adhesion part, 9 ... Adhesive

Claims (6)

  A block copolymer comprising a first monomer having a side chain of an alkane chain and (a) a side chain of a polyoxyethylene structure or (b) a second monomer having a substituent having a tertiary amine structure A composition intended to be adsorbed on the surface of polyethylene.   The composition according to claim 1, wherein the first monomer is one or more selected from the group consisting of behenyl acrylate, stearyl acrylate, and lauroyl acrylate.   The second monomer is di (ethylene glycol) ethyl ether acrylate, polyethylene glycol-monoacrylate, methoxy-polyethylene glycol-acrylate, 2- (diethylamino) ethyl methacrylate, 2- (dimethylamino) ethyl methacrylate, 2- (tert -Butylamino) ethyl methacrylate, N, N-dimethylacrylamide, N, N-dimethylaminopropylacrylamide, N, N-diethylacrylamide, and 1 selected from the group consisting of methacrylates or acrylates having polar groups at the side chain sites It is the above, The composition of Claim 1 or 2 characterized by the above-mentioned. A polyethylene porous membrane;
The composition according to any one of claims 1 to 3, filled in the polyethylene porous membrane,
Lithium ions supported on the polyethylene porous membrane;
A separator for a lithium secondary battery, comprising: A polyethylene porous membrane;
The composition according to any one of claims 1 to 3, filled in the polyethylene porous membrane,
Lithium ions supported on the polyethylene porous membrane;
A solid electrolyte for a lithium secondary battery, comprising: A substrate made of polyethylene;
The composition according to any one of claims 1 to 3, wherein at least a part of the surface of the base material is modified.
Polyethylene products with

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