KR100550863B1 - A method of preparing for a modified ultra high molecular weight polyethylene having improved adhesive strength and a modified ultra high molecular weight polyethylene thereby - Google Patents

Abstract

The present invention relates to a method for producing modified ultra high molecular weight polyethylene having improved adhesion, and to a modified ultra high molecular weight polyethylene prepared accordingly.

Mixing 0.1-30 parts by weight of ultra high molecular weight polyethylene and 99.1-70 parts by weight of an organic solvent; In the mixture formed in the step, acrylic acid, methacrylic acid, methyl methacrylate, ethacrylic acid, maleic acid, fumaric acid, glycidyl methacrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate Hydrogen bond group selected from the group consisting of monoethyl maleate, diethyl maleate, di-normal-butyl maleate, maleic anhydride, 5-norbornene-2, 3-anhydride, and nadic anhydride Adding 5-50 phr of the grafting monomer having to the ultrahigh molecular weight polyethylene, and adding 1-20 phr of a reaction initiator; And extruding the mixture through a twin screw extruder while reacting at a temperature of 120-200 ° C .; a method for producing modified ultra high molecular weight polyethylene having improved adhesion and modified modified having improved adhesive prepared by the method Ultra high molecular weight polyethylene is provided.

According to the present invention, the hydrogen bond group is grafted to synthesize ultra high molecular weight polyethylene having improved adhesive strength.

Ultra high molecular weight polyethylene, graft, adhesion, hydrogen bonding group, methacrylic acid

Description

METHODS OF PREPARING FOR A MODIFIED ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE HAVING IMPROVED ADHESIVE STRENGTH AND A MODIFIED ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE THERE

Figure 1 is a Fourier Transform Infra-Red (FTIR) measurement results showing how the grafted methyl methacrylate or maleic anhydride monomer to the modified ultra high molecular weight polyethylene produced by the present invention.

The present invention relates to a method for producing a modified ultra high molecular weight polyethylene and to a modified ultra high molecular weight polyethylene produced according to the above, and more particularly to a method for producing an ultra high molecular weight polyethylene modified to give improved adhesion to ultra high molecular weight polyethylene and A modified ultra high molecular weight polyethylene.

In general, polyolefin resins are used for various purposes because of their light weight and low price, as well as excellent mechanical and electrical properties. In particular, polyethylene has a simple structure and excellent processability, which is widely used for manufacturing films, containers, and vinyl bags, and is widely used in researches on polymer processing such as extrusion and injection.

Ultra-high molecular weight polyethylene (UHMWPE), which has a molecular weight of more than millions of polyethylene, is called ultra high molecular weight polyethylene (UHMWPE), which exhibits strong mechanical properties of tens to hundreds of G Pa when it is oriented to the polymer chain through excellent mechanical properties, especially stretching. Many applications using this are expected. However, since polyethylene and ultra high molecular weight polyolefins are non-polar, their use range has been limited because of their poor compatibility and adhesion with polyolefins of the same type as well as polar substrates such as nylon, polyester, aluminum, iron, paper, and wood.

In addition, ultra-high molecular weight polyethylene is difficult to process through general extrusion or injection process because it is not flowable, and it is used by molding into a film using gel or wet technology that gives heat fluidity by mixing with solvent. .

To date, many studies have been conducted to improve the non-adhesive properties of polyolefins, especially polyethylene. U.S. Patent No. 4,612,155 describes the type and content of the two components based on rheological properties with respect to the method of continuous grafting in the presence of the maleic anhydride bicomponent, and in U.S. Patent 4,762,890, A method of dissolving an initiator in a solvent and injecting it into a twin screw extruder with a liquid injector is described. In addition, in order to give adhesion to ultra high molecular weight polyethylene, hydrogen peroxide was deposited on a 1 mm thick film, and then it was deposited using a spinning method into a methyl methacrylate (MMA) solution, followed by polymerization of MMA on an ultra high molecular weight polyethylene film. .

However, the above method takes a lot of process time and cost, and the manufacturing process is also complicated, the manufacturing cost is high. In addition, low molecular weight polyethylene (LMWPE) can be modified relatively easily by introducing MAH or MMA using reactive extrusion.However, high molecular weight polyethylene does not allow general melt processing due to high molecular weight. It cannot be modified by the conventional method as described above.

It is an object of the present invention to provide a modified ultra high molecular weight polyethylene production method with improved adhesive strength.

Another object of the present invention is to provide a modified ultra high molecular weight polyethylene having improved adhesion prepared by the above method.

According to one aspect of the invention,

Mixing 0.1-30 parts by weight of ultra high molecular weight polyethylene and 99.1-70 parts by weight of an organic solvent;

In the mixture formed in the step, acrylic acid, methacrylic acid, methyl methacrylate, ethacrylic acid, maleic acid, fumaric acid, glycidyl methacrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate , A hydrogen bond group selected from the group consisting of monoethyl maleate, diethyl maleate, di-normal-butyl maleate, maleic anhydride, 5-norbornene-2, 3-anhydride, and nadic anhydride Adding 5-50 phr of the grafting monomer having to the ultrahigh molecular weight polyethylene, and adding 1-20 phr of a reaction initiator; And

Extruding the mixture through a twin screw extruder while reacting at a temperature of 120-200 ° C .;

Provided is a modified ultra high molecular weight polyethylene production method having improved adhesion comprising a.

According to another aspect of the present invention,

Modified ultrahigh molecular weight polyethylene having improved adhesion prepared by the above method is provided.

Hereinafter, the present invention will be described in detail.

In the method of the present invention, modified ultra-high molecular weight by improving CO 2 functional group by introducing COOH functional groups into ultra-high molecular weight polyethylene by modifying the ultra-high molecular weight polyethylene by reactive extrusion using gel or wet technology. To produce polyethylene.

The modified ultra high molecular weight polyethylene having improved adhesive strength of the present invention is prepared by graft reaction of a monomer having a hydrogen bond group to ultra high molecular weight polyethylene.

The modified ultra high molecular weight polyethylene of the present invention is prepared by mixing ultra high molecular weight polyethylene with an organic solvent, then adding a grafting monomer having a hydrogen bonding group and a reaction initiator, and extruding it through a twin screw extruder while reacting at a temperature of 120-200 ° C. Are manufactured.

As the organic solvent, decalin, xylene, paraffin oil, toluene or cyclohexane may be used. Preferably, a mixture of decalin and paraffin oil in a ratio of 7: 3 may be used.

The mixing ratio of the ultra high molecular weight polyethylene and the organic solvent is mixed in a ratio of ultra high molecular weight polyethylene 0.1-30: 99.1-70 weight ratio of the organic solvent. If the mixing ratio of ultra high molecular weight polyethylene and organic solvent is out of the above range, for example, if the ultra high molecular weight polyethylene is mixed too little (too much organic solvent is mixed), the ratio of solvent to polymer is too low. If the gel is not gelled and the ultra high molecular weight polyethylene is mixed too much (when the organic solvent is mixed too little), the fluidity of the polymer is very low and the reforming reaction is difficult to occur, and the extrusion process is difficult to perform.

Monomers having a hydrogen bond group grafted to the ultrahigh molecular weight polyethylene used in the present invention include unsaturated carboxylic acids such as acrylic acid, methacrylic acid, methyl methacrylate, ethacrylic acid, maleic acid and fumaric acid, and glycidyl meta Ethylenically unsaturated carboxyl esters such as acrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate, monoethyl maleate, diethyl maleate, di-normal-butyl maleate, and maleic And ethylenically unsaturated carboxylic acid anhydride monomers such as hydride, 5-norbornene-2, 3-anhydride, and nadic anhydride. Preferably methyl methacrylate or maleic anhydride can be used.

These monomers are added to the ultra-high molecular weight polyethylene at 5-50 phr, and if the amount is less than 5 phr, the modification of the ultra-high molecular weight polyethylene is too small to give the adhesive force effectively, and when the 50 phr or more, the ungrafted monomer is excessively It remains inside the ultrahigh molecular weight polyethylene, which causes a decrease in adhesive strength and physical properties.

Reaction initiators used in the present invention include acyl peroxides such as benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, cumyl butyl peroxide, 1,1-di-t-butylperoxy-3, Dialkyl or aralkyl peroxides, such as 5,5-trimethyl cyclohexane, 2,5-dimethyl-2,5-di-t-butylperoxyhexane and bis (t-butylperoxy isopropyl) benzene, t- Butylperoxy pivalate, t-butyl di (perphthalate), dialkyl peroxy monocarbonate, peroxy dicarbonate, t-butylperbenzoate, 2,5-dimethylhexyl-2,5-di (perbenzo ) And peroxy esters such as t-butyl peroctoate, hydroperoxides such as t-butylhydro peroxide, p-methane idro peroxide, pinane hydro peroxide and cumene hydro peroxide, cyclohexanone peroxide and the like And ketones such as methyl ethyl ketone peroxide and the like Azo compound systems such as peroxide and azobis isobutyronitrile and the like, and particularly preferably dicumyl peroxide may be used. The initiator is used in amounts of 1-20 phr per 100 parts by weight relative to ultra high molecular weight polyethylene. When the initiator is used in an amount of 1 phr or less, the adhesive force is not secured because the monomer is not sufficient for the phoft reaction of the ultra high molecular weight polyethylene chain, and an excess of unreacted monomer may be left in the ultra high molecular weight polyethylene according to the correlation with the monomer. Can be. In addition, when used in more than 20 phr of the graft reactant of the present invention due to the rapid increase in the melt viscosity at the composition ratio and reaction temperature conditions, the flow characteristics of ultra high molecular weight polyethylene is not suitable.

After preparing the graft reaction mixture solution as described above it is extruded through a twin screw extruder while the graft reaction.

The graft process is prepared by a continuous process in which the graft reaction mixture solution is dropped and melt mixed in a temperature-set biaxial extruder. The extruder's set temperature is 120-200 ℃, and if it is lower than 120 ℃, melting of ultra high molecular weight polyethylene is not smooth and graft reaction is not smooth. If it is higher than 200 ℃, the degree of crosslinking reaction is increased. The melt viscosity of the modified modified ultra high molecular weight polyethylene becomes a factor. Preferably the reaction temperature is a temperature of 160-180 ℃.

The extruded material is dissolved in hot xylene, precipitated in cold acetone, and dried at a constant temperature to obtain modified ultrahigh molecular weight polyethylene having improved adhesion to a hydrogen bond group grafted onto an ultrahigh molecular weight polyethylene backbone.

The modified ultrahigh molecular weight polyethylene of the present invention is applicable to the manufacture of sheets of battery separators or green sheets of thin films through extrusion or stretching methods.

Hereinafter, the present invention will be described in more detail with reference to the following examples. The examples illustrate the present invention and do not limit the present invention to the following examples.

Example 1

After mixing 10 parts by weight of ultra high molecular weight polyethylene (UHMWPE) (molecular weight 3,000,000) and 90 parts by weight of decarin, methyl methacrylate is added to the mixture to 10 phr of the ultra high molecular weight polyethylene and dicumyl peroxide as a reaction initiator. 5phr was added and stirred for 10 minutes at room temperature. The mixture was then extruded into a twin-screw extruder rotating at a screw rotation speed of 20 rpm. At this time, the reaction temperature of the mixture passing through the extruder was set to 160 ~ 180 ℃. The extruded material was dissolved in hot xylene and precipitated in cold acetone. This was dried at 60 ° C. to obtain a modified ultra high molecular weight polyethylene.

Example 2

10 parts by weight of ultra high molecular weight polyethylene (UHMWPE) and 90 parts by weight of decarin are mixed, and maleic anhydride is added to the mixture to 10 phr of the ultra high molecular weight polyethylene, and dicumyl peroxide is added as a reaction initiator. Stir at 10 min. The mixture was then extruded into a twin screw extruder rotating at a screw rotation speed of 20 rpm. At this time, the reaction temperature of the mixture passing through the extruder was set to 160 ~ 180 ℃. The extruded material was dissolved in hot xylene and precipitated in cold acetone. This was dried at 60 ° C. to obtain a modified ultra high molecular weight polyethylene.

Example 3

10 parts by weight of ultra high molecular weight polyethylene (UHMWPE) and 90 parts by weight of decarin are mixed, and then methyl methacrylate or maleic anhydride is added 10 phr to the ultra high molecular weight polyethylene and benzoyl peroxide as a reaction initiator. Then it was stirred for 10 minutes at room temperature. The mixture was then extruded into a twin screw extruder rotating at a screw rotation speed of 20 rpm. At this time, the reaction temperature of the mixture passing through the extruder was set to 160 ~ 180 ℃. The extruded material was dissolved in hot xylene and precipitated in cold acetone. This was dried at 60 ° C. to obtain a modified ultra high molecular weight polyethylene.

Example 4

10 parts by weight of ultra high molecular weight polyethylene (UHMWPE) and 90 parts by weight of a mixed solvent in which decarine and paraffin oil were mixed at 7: 3) were mixed, and then methyl methacrylate or maleic anhydride was added to the mixture. 10 phr was added thereto and benzoyl peroxide as a reaction initiator was added, followed by stirring at room temperature for 10 minutes. The mixture was then extruded into a twin screw extruder rotating at a screw rotation speed of 20 rpm. At this time, the reaction temperature of the mixture passing through the extruder was set to 160 ~ 180 ℃. The extruded material was dissolved in hot xylene and precipitated in cold acetone. This was dried at 60 ° C. to obtain a modified ultra high molecular weight polyethylene.

Example 5

10 parts by weight of ultra high molecular weight polyethylene (UHMWPE) and 90 parts by weight of a mixed solvent in which decarine and paraffin oil were mixed at 7: 3 were mixed, and then, methacrylic acid was added to the mixture with 30 phr of the ultra high molecular weight polyethylene as a reaction initiator. Benzoyl peroxide was added and then stirred at room temperature for 10 minutes. The mixture was then extruded into a twin screw extruder rotating at a screw rotation speed of 20 rpm. At this time, the reaction temperature of the mixture passing through the extruder was set to 160 ~ 180 ℃. The extruded material was dissolved in hot xylene and precipitated in cold acetone. This was dried at 60 ° C. to obtain a modified ultra high molecular weight polyethylene.

Example 6-Confirmation of Grafting

Fourier transform infra-red (FTIR) was used to identify the hydrogen bond groups of ultra-high molecular weight polyolefins grafted with methyl methacrylate (MMA) and maleic anhydride (MAH), which are monomers capable of imparting hydrogen bonds. 1735㎝ C = O appearing at ^-1 (carbonyl) obtaining the ratio of the absorbency of the CH ₂ peaks appearing in the 760-680㎝ ^-1 for the absorbency of the peak did you boot how the MMA is grafted ultrahigh-molecular weight polyolefin quantitatively to It was. And 1830-1750㎝ ^-1 and 1750-1660㎝ ^-1 C = O shown in (carbonyl) MAH the ultrahigh obtain the ratio of the absorbency of the CH ₂ peaks appearing in the 760-680㎝ ^-1 for the absorbency of the peak It was confirmed quantitatively how grafted to the molecular weight polyolefin. Absorption measurement results are shown in FIG.

Example 7-Adhesion Strength Test

In order to measure the adhesive strength of each sample, each sample was pressed and bonded at 130 ° C. and 8 MPa for 3 minutes using a single screw compressor, and then the adhesive strength was measured using a push-pull guage. The measured adhesive strength is as follows.

Example Peel Strength (kgf / cm) One 260 2 320 3 350 4 420 5 460

In general, as shown in Table 1, the ultrahigh molecular weight polyethylene before the modification is 100 kgf / cm or less, compared to the ultra-high molecular weight polyethylene modified by the method of the present invention exhibits a strength of 260 to 460 kgf / cm up to very good It can be seen that the adhesive strength.

According to the present invention, the hydrogen bond group is grafted to synthesize an ultra high molecular weight ultra high molecular weight polyethylene having improved adhesive strength.

The ultrahigh molecular weight ultrahigh molecular weight polyethylene with improved adhesive strength prepared according to the present invention may be manufactured as a sheet of a battery separator or a green sheet of a thin film through an extrusion or stretching method.

In addition, by using the reaction extrusion method according to the method of the present invention can easily mass-produce ultra-high molecular weight polyethylene with improved adhesive strength can reduce the manufacturing cost.

In addition, the use of ultra high molecular weight ultra high molecular weight polyethylene with improved adhesive strength of the present invention in manufacturing green sheet can reduce the repulsive force between the green sheet and the electrode layer due to the strong elastic modulus of the green sheet when manufactured in the existing DSM and also the film formability Can be improved. In addition, by using a polymer that can impart a hydrogen bonding force in the production of the green sheet, the weak adhesion due to the nonpolar nature of the existing polyolefin can be improved through the hydrogen bonding.

Claims (9)

Mixing 0.1-30 parts by weight of ultra high molecular weight polyethylene and 99.1-70 parts by weight of an organic solvent; In the mixture formed in the step, acrylic acid, methacrylic acid, methyl methacrylate, ethacrylic acid, maleic acid, fumaric acid, glycidyl methacrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate Hydrogen bond group selected from the group consisting of monoethyl maleate, diethyl maleate, di-normal-butyl maleate, maleic anhydride, 5-norbornene-2, 3-anhydride, and nadic anhydride Adding 5-50 phr of the grafting monomer having to the ultrahigh molecular weight polyethylene, and adding 1-20 phr of a reaction initiator; And Extruding the mixture through a twin screw extruder while reacting at a temperature of 120-200 ° C .; Method for producing a modified ultra high molecular weight polyethylene having improved adhesion comprising a. The method of claim 1, wherein the organic solvent is selected from the group consisting of decalin, xylene, paraffin oil, toluene, and cyclohexane. The method of claim 1 or 2, wherein the organic solvent is characterized in that the decalin and paraffin oil is mixed in a ratio of 7: 3. The method of claim 1, wherein the reaction initiator is benzoyl peroxide, di-t-butyl peroxide, dicumyl peroxide, cumyl butyl peroxide, 1,1-di-t-butylperoxy-3,5,5- Trimethyl cyclohexane, 2,5-dimethyl-2,5-di-t-butylperoxyhexane, bis (t-butylperoxy isopropyl) benzene, t-butylperoxy pivalate, t-butyl di (perphthalate ), Dialkyl peroxy monocarbonate, peroxy dicarbonate, t-butylperbenzoate, 2,5-dimethylhexyl-2,5-di (perbenzoate), t-butyl peroctoate, t-butyl Hydroperoxide, p-methane idro peroxide, pinane hydro peroxide, cumene hydro peroxide, cyclohexanone peroxide, methylethylketone peroxide and azobis isobutyronitrile Way. The method of claim 1 or 4, wherein the reaction initiator is dicumyl peroxide. The method of claim 1 wherein the grafting monomer is methyl methacrylate or maleic anhydride. The method of claim 1, wherein the reaction temperature is 160-180 ℃. The method of claim 1 further characterized in that the extruded material is dissolved in hot xylene and then precipitated in cold acetone. delete

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