KR101614525B1 - Method for modified polyolefin resin - Google Patents

Abstract

The present invention relates to a method for producing a polyolefin resin, comprising the steps of: injecting a polyolefin resin and a photoreactive monomer into a packaging bag; And irradiating the packaging bag with an electron beam of 1 to 50 kGy. [0002] The present invention relates to a method for producing a modified polyolefin resin. Such a method of producing a modified polyolefin resin minimizes the exposure to the outside to minimize contamination and grafts the functional monomer by a simple method, thereby increasing the productivity and economical efficiency of the process.

Description

METHOD FOR MODIFIED POLYOLEFIN RESIN [0002]

The present invention relates to a process for producing a modified polyolefin resin, and more particularly, to a process for producing a modified polyolefin resin by minimizing exposure to the outside to minimize contamination and grafting the functional monomer by a simple method, To a process for producing the modified polyolefin resin.

In general, polyolefin resins are excellent in mechanical properties, optical and chemical properties, and moldability, and are advantageously used in a wide range in terms of cost. However, a polyolefin resin consisting essentially of a hydrocarbon only has a very low chemical reactivity as compared with resins containing a relatively polar functional group as a nonpolar material, and has a problem in blending because it has poor affinity with other kinds of resins. In addition, there is a limit to improving the properties such as thermal adhesiveness and printing and coating.

In order to solve these problems, a modified polyolefin resin was previously prepared by introducing monomers having various functions to the polyolefin resin and applied to various fields.

The method of introducing such a polar functional group can be largely divided into a method of grafting a monomer using an extruder, a method of grafting in a solid phase, and a method of grafting a monomer in a solution state.

In the case of a process using an extruder, the time required for production of the product is short, but there is a limit in that the amount of monomer grafted to the product is small and unreacted materials can not be removed.

The method of grafting in a solid phase is a grafting method in which a polyolefin is swollen in a solid state in a state of being swollen with a solvent. Although the production process is simple, the amount of grafting is small and the use limit is limited depending on the particle size of the polyolefin used .

The method of grafting in a solution state has a drawback that the grafting rate is high and the physical properties of the product are good, but the solvent is refined using an excessive amount of solvent and the procedure is complicated and the manufacturing time is longer than other methods. In addition, since the particle size of a product to be manufactured is too small, there are many difficulties in packaging and transporting operations.

More specifically, Korean Patent Laid-Open Publication No. 10-2009-0072770 and Korean Patent Laid-Open Publication No. 10-2012-0072004 disclose a process for producing a polyolefin, which comprises the steps of (i) introducing a polyolefin, a monomer and an initiator into an extruder, (Iii) a polyolefin is completely dissolved in a solvent in a high-temperature / high-pressure reactor, and then the monomers are reacted. However, these processes are accompanied by the necessity of re-opening and repacking the already prepared polyolefin, which may lead to contamination and loss in the extrusion process, and may result in purification and drying of the solvent and radical initiator A process is required.

Therefore, the operation loss and repacking occurring in the above-mentioned modification process become the main factor of cost increase and become a limitation of commercialization, and the contaminants generated during the reforming process or the reforming process cause the quality problem of the finished polyolefin resin finished product .

Accordingly, there is a need to develop a method for producing a modified polyolefin resin that minimizes the exposure to the outside to minimize contamination, grafts the functional monomer by a simple method, and increases the productivity and economy of the process.

Korean Patent Laid-Open No. 10-2009-0072770 Korean Patent Laid-Open No. 10-2012-0072004

The present invention provides a method for producing a modified polyolefin resin which can minimize contamination by minimizing exposure to the outside and graft the functional monomer by a simple method, thereby increasing the productivity and economy of the process.

The present invention provides a method of manufacturing a packaging bag, comprising: injecting a polyolefin resin and a photoreactive monomer into a packaging bag; And irradiating the packaging bag with an electron beam of 1 to 50 kGy. The present invention also provides a method for producing a modified polyolefin resin.

Hereinafter, a method for producing a modified polyolefin resin according to a specific embodiment of the present invention will be described in detail.

According to an embodiment of the present invention, there is provided a method of manufacturing a package, comprising: injecting a polyolefin resin and a photoreactive monomer into a packaging bag; And irradiating the packaging bag with electron beams of 1 to 50 kGy, may be provided.

The inventors of the present invention have studied a method for modifying a polyolefin to improve the mechanical properties and processability of a polyolefin and impart various functions. As a result, it has been found that a polyolefin resin and a photoreactive monomer are injected into a packaging bag, It has been confirmed through experimentation that a modified polyolefin resin can be produced by grafting a photoreactive monomer onto a polyolefin resin by a simple method of irradiating an electron beam with an irradiation dose.

In particular, the method of producing the modified polyolefin resin is economical in that it does not cause contamination or processing defects in the manufacturing process unlike the conventional peroxide modification method, and has a very small amount of work loss. In addition, the above manufacturing method can omit the step of unpacking and repackaging the package, so that the modified polyolefin resin can be produced by modifying the polyolefin resin by a simple and economical method.

The photoreactive monomer injected into the packaging bag together with the polyolefin resin may be in the form of a liquid or a powder having a low melting point. The monomers may be introduced into a packaging bag by a master batch method, The polyolefin resin and, if desired, other additives.

Examples of such photoreactive monomers include acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, dicarboxylic acids having a double bond, dicarboxylic acid esters having a double bond, dicarboxylic acid anhydrides having a double bond , Silane coupling agents, or mixtures thereof.

The photoreactive monomer may be uniformly grafted to the polyolefin resin by being irradiated with an electron beam in a specific irradiation dose in a packed state together with the polyolefin resin. The polyolefin resin grafted with the photoreactive monomer And may have different properties or properties depending on the type and nature of the monomer.

In one embodiment of the photoreactive monomer, the dicarboxylic acid is selected from the group consisting of maleic acid, phthalic acid, itaconic acid, citraconic acid, alkenylsuccinic acid, cis-1,2,3,6 tetrahydrophthalic acid, (Meth) acrylic acid compound may be selected from the group consisting of acrylic acid, methacrylic acid, vinyl acetic acid, vinyl acetate, methyl-acrylic acid, ethyl-acrylic acid, butyl-acrylic acid, methyl-methacrylic acid, And silane coupling agents may be vinyltrimethoxysilane, vinyltriethoxysilane, gamma-metaacryloxypropyltrimethoxysilane, gamma-acroxypropyltrimethoxy Silane, and acroxymethyltrimethoxysilane.

In particular, maleic anhydride, methacrylic acid, or gamma-methacryloxypropyltrimethoxysilane may be used as the photoreactive monomer in the method for producing the modified polyolefin resin of one embodiment. Since maleic anhydride can reactively bond with various chemical species, it is possible to produce a modified polyolefin resin having improved adhesion to metals and polar plastic materials by grafting maleic anhydride to the polyolefin resin, It is possible to produce a modified polyolefin resin having excellent mechanical strength by grafting methacrylic acid to the polyolefin resin. Further, a modified polyolefin resin excellent in water permeability and adhesion can be produced by grafting a gamma-metaacryloxypropyltrimethoxysilane coupling agent capable of condensation polymerization onto a polyolefin resin.

The amount of the photoreactive monomer may be 0.1 to 10 parts by weight, preferably 0.1 to 3 parts by weight based on 100 parts by weight of the polyolefin resin. When the content of the photoreactive monomer is less than 0.1 part by weight, it is difficult to prepare the polyolefin resin uniformly grafted with the photoreactive monomer, and when the content of the photoreactive monomer exceeds 10 parts by weight, a large amount of unreacted photoreactive monomer remains So that the economical efficiency may be lowered.

Examples of the polyolefin resin include polyethylene, polypropylene, ethylene vinyl acetate, ethylene-propylene copolymer, ethylene elastomer, propylene elastomer, ethylene plastomer, propylene Plastomer, or a mixture thereof. The polyethylene may include a low density polyethylene (LDPE), a linear low density polyethylene (LLDPE), a medium density polyethylene (MDPE), a high density polyethylene (HDPE), or a mixture thereof. The polyolefin resins may be injected into the packaging bag together with the photoreactive monomer and irradiated with an electron beam to produce a modified polyolefin grafted with the photoreactive monomer.

Ethylene vinyl acetate having a melt index of 1 to 500 g / 10 min and a vinyl acetate content of 5 to 40 wt% may be used as the polyolefin resin. When the modified polyolefin resin is produced using ethylene vinyl acetate having the melt index and vinyl acetate content as described above, a modified ethylene vinyl acetate resin having excellent mechanical properties and processability can be produced.

In the method for producing a modified polyolefin resin according to one embodiment of the present invention, the packing bag may be selected from materials having a property of directly or indirectly irradiating the polyolefin resin and the photoreactive monomer injected therein, , Coated paper, paper containing liner film, film, yarn woven fabric, cloth, and the like.

On the other hand, the step of irradiating the packaging bag with the electron beam can be carried out by placing the packaging bag in a metal roll or a metal frame-type conveyor and passing through the electron beam irradiation section. Therefore, if the irradiation of the electron beam is continued, the temperature of the metal roll or the mold may rise to 90 ° C or higher, the packaging bag may melt, the contents may flow into the packaging bag, or the packaging bag may not move smoothly on the conveyor. In order to prevent this, it is preferable to use a packing bag made of a material which is stable even at a high temperature as a main material.

The size and shape of the packaging bag are not limited. However, the height of the packaging bag may be 0.1 to 30 cm, preferably 1 to 10 cm, the height of the packaging bag may be constant, and the polyolefin resin and the photoreactive monomer may be injected Is preferable.

The step of irradiating the packaging bag with the electron beam may be irradiated on the packaging bag in one or both sides. When the thickness of the packing bag into which the polyolefin resin and the photoreactive monomer are injected is thin, the cross-sectional irradiation is preferable. When the thickness is thick, the double-sided irradiation is preferable, and the electron beam irradiation can be performed once or twice on both sides or cross- . Also, depending on the shape and position of the irradiation device, the packaging bag may be laid-up or laid-down. Preferably, the bag may be laid down under the irradiation device located at the upper portion.

The amount of electron beam irradiation in the step of irradiating the packing bag with the electron beam may be varied depending on the kind and content of the monomer and the type of the polyolefin resin. The electron beam dose required for the photoreactive monomer grafting may be 1 to 50 kGy Preferably from 5 to 20 kGy.

On the other hand, an antioxidant, a slip agent, an antiblocking agent, a UV stabilizer, a reaction aid, or a mixture thereof may be further injected into the inside of the packaging bag as an additive. The additives may be injected into the packaging bag in a masterbatch method, or may be injected directly into a liquid or solid form.

The antioxidant can increase the thermal stability and the oxidation stability of the modified polyolefin resin to be produced. Specifically, the antioxidant may be a phenol-based antioxidant, a biphenol-based antioxidant, or a mixture thereof. In order to lower the shear rate of shearing of the polyolefin resin and minimize discoloration, the use of a biphenol- desirable.

As the phenolic antioxidant, antioxidants known to be commonly used in the art may be used without limitation, for example, octadecyl-3- (3,5-di-tert.butyl-4-hydroxyphenyl) -propionate Butylated hydroxytoluene, Pentaerythritol tetrakis (3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate), 2 ', 3-bis [3- [3,5- hydroxyphenyl] propionyl]] propionohydrazide, or a mixture thereof.

As the non-phenolic antioxidant, antioxidants known to be commonly used in the art may be used without limitation, for example, Tris (2,4-ditert-butylphenyl) phosphite, 4,4'-Thiobis (6-tert-butyl-m-cresol), Bis- (2,4-di-t-butylphenol) Pentaerythritol Diphosphite, 2- (tert- , 8,10-tetrakis (tert-butyl) dibenzo [d, f] [1,3,2] dioxaphosphepin-6-yl) oxy) propyl) -methylphenyl) -ethyl-phosphite, Tris (Nonylphenyl) Phosphite, or a mixture thereof.

The antioxidant may be included in an amount of 0.01 to 0.5 parts by weight based on 100 parts by weight of the polyolefin resin. If the antioxidant is contained in an excessively small amount, the oxidized stability of the produced modified polyolefin resin may be weakened, and if the antioxidant is contained in an excessively large amount, the electron beam modification efficiency may be greatly lowered and discoloration of the polyolefin resin may be caused.

Examples of the anti-blocking agent include, but are not limited to, olefins, stearamide, erucamide, ethylene bis-stearamide, ethylene bis- oleamide, or a mixture thereof. The antiblocking agent may be included in an amount of 0.02 to 0.5 part by weight based on 100 parts by weight of the polyolefin resin. If the content of the anti-blocking agent is too high, it may cause a color change in the electron beam modification process. When the content of the anti-blocking agent is too low, a problem of sticking to the pellets occurs. Therefore, desirable.

As the ultraviolet stabilizer, a hindered amine-based ultraviolet stabilizer may be preferably used. Hindered amine stabilizer compounds known to be commonly used in the art may be used without limitation. In particular, by including such an ultraviolet stabilizer additionally, the required amount of electron beam to satisfy the target physical properties of the modified polyolefin resin can be kept low.

Specific examples of the ultraviolet stabilizer include Polymer of dimethyl succinate and 4-hydroxy-2,2,6,6-tetramethyl-1-piperidine ethanol, Bis (2,2,6,6-tetramethyl-4-piperidinyl) sebacate, Bis 1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, Poly [6 - [(1,1,3,3-tetramethylbutyl) amino] -1,3,5-triazine- [(2,2,6,6-tetramethyl-4-piperidinyl) imino] hexamethylene [2,2,6,6-tetramethyl-4-piperidinyl] imino]] or a mixture thereof, And 0.01 to 0.5 parts by weight of an ultraviolet stabilizer based on 100 parts by weight of the resin.

As the reaction aid, a peroxide type crosslinking agent and a crosslinking aid may be used. The peroxide crosslinking agent is dicumyl peroxide, 1,1-di- (tert-butylperoxy) -3,3,5-trimethyl cyclohexane, di (2-tert-butyric-peroxy-isopropyl) -benzene , butyl-4,4-bis (tert-butyl-di-oxy) balreo acrylate, di- (2,4-dichlorobenzoyl) peroxide, di- (2,4-dichlorobenzoyl) peroxide, dibenzoyl peroxide , tert-butyl peroxybenzoate, tert-butyl cumyl peroxide, 2,5-dimethyl-2,5-di- (tert-butylperoxy) - hexane, di-tert-butyl peroxide, 2,5- Dimethyl-2,5-di ( tert -butylperoxy) hex-3 or a mixture thereof. Examples of the crosslinking aid include triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylpropane trimethacrylate, divinylbenzene, ethylene glycol dimethacrylate, pentaerythritol triacrylate, Trimethylol propane triacrylate, triaryl isocyanurate, or a mixture thereof.

According to the present invention, it is possible to provide a method for producing a modified polyolefin resin which can minimize contamination by minimizing exposure to the outside, graft the functional monomer by a simple method, and increase the productivity and economy of the process .

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

[ Example  1 to 2]: Silane Coupling agent  Degeneration using Polyolefin  Manufacture of resin

An ethylene vinyl acetate resin and a silane coupling agent (gamma-methacryloxypropyltrimethoxysilane) having a melt index of 30 g / 10 min and a vinyl acetate content of 33 wt% were packed in a packaging bag of 800 mm * 565 mm in size, 1, and irradiated with electron beams for several seconds to prepare a modified ethylene vinyl acetate resin.

The content of the unreacted silane coupling agent was measured using a liquid chromatograph apparatus and is shown in Table 1 below.

Silane coupling agent input
(Parts by weight) Irradiation dose
(kGy) Silane coupling agent residual amount
(Parts by weight) Example 1 1.00 0 1.00 5 0.48 10 0.24 15 0.15 20 0.09 Example 2 2.00 0 2.00 5 1.30 10 0.98 15 0.74 20 0.38

[ Example  3 to 4]: Maleic anhydride  Degeneration using Polyolefin  Manufacture of resin

Modified ethylene vinyl acetate resin was prepared in the same manner as in Examples 1 and 2 except that maleic anhydride was used instead of the silane coupling agent.

Then, the content of unreacted silane coupling agent was measured by Gas Chromatography equipment and is shown in Table 2 below.

Amount of maleic anhydride charged (parts by weight) Irradiation dose (kGy) Maleic anhydride residue (parts by weight) Example 3 0.1 0 0.14 5 0.07 10 0.02 15 0.005 20 0.0005 Example 4 0.3 0 0.27 5 0.22 10 0.13 15 0.13 20 0.10

[ Comparative Example  One, Example  5 to 6]: Methacrylic acid  Degeneration using Polyolefin  Manufacture of resin

A denatured ethylene vinyl acetate resin was prepared in the same manner as in Examples 1 and 2 except that methacrylic acid was used instead of the silane coupling agent.

The mechanical strength of the polyacrylic resin grafted with methacrylic acid is shown in Table 3 below.

Methacrylic acid dosage
(Parts by weight) Irradiation dose (kGy) The tensile strength
kg / mm ² ) Comparative Example 1 0 0 1.99 Example 5 One 3 2.34 Example 6 3 3 2.10

When the modified polyolefin is produced by the manufacturing method of the above embodiment, the polyolefin resin grafted with the photoreactive monomer can be prepared by a simple method of injecting a polyolefin resin and a photoreactive monomer into a packaging bag and irradiating an electron beam of a specific irradiation dose have.

As shown in Tables 1 and 2, it can be confirmed that the residual amount of the photoreactive monomer is remarkably reduced when a small amount of 5 kGy is irradiated as compared with the case where the electron beam is not irradiated. In particular, when the electron beam is not irradiated, the silane coupling agent remains in the ethylene vinyl acetate resin without being grafted. However, when a specific irradiation dose of electron beam is irradiated, a large amount of silane coupling agent can be grafted to the ethylene vinyl acetate resin can confirm.

As shown in Table 3, in Examples 5 to 6 in which the photoreactive monomer was grafted, the tensile strength was remarkably improved as compared with Comparative Example 1 in which the photoreactive monomer was not grafted, and the polyolefin resin Can be produced. This increase in tensile strength is considered to be caused by the grafted methacrylic acid in the polyolefin resin inducing hydrogen bonding.

Claims (11)

Injecting ethylene vinyl acetate and a photoreactive monomer having a melt index of 1 to 500 g / 10 min and a vinyl acetate content of 5 to 40% by weight into the inside of the package bag; And
And irradiating the packaging bag with an electron beam of 1 to 50 kGy.
The method according to claim 1,
Examples of the photoreactive monomer include acrylic acid, acrylic acid esters, methacrylic acid, methacrylic acid esters, dicarboxylic acid having a double bond, dicarboxylic acid esters having a double bond, dicarboxylic acid anhydride having a double bond, A silane coupling agent, and a silane coupling agent.
3. The method of claim 2,
Wherein the photoreactive monomer is maleic anhydride, methacrylic acid, or gamma-methacryloxypropyltrimethoxysilane.
The method according to claim 1,
Wherein the photoreactive monomer is injected at 0.1 to 10 parts by weight per 100 parts by weight of the polyolefin resin.
The method according to claim 1,
Wherein the polyolefin resin is a modified polyolefin resin comprising at least one resin selected from the group consisting of polyethylene, polypropylene, ethylene vinyl acetate, ethylene-propylene copolymer, ethylene elastomer, propylene elastomer, ethylene plastomer, and propylene plastomer ≪ / RTI >
6. The method of claim 5,
Wherein said polyethylene comprises at least one selected from the group consisting of low density polyethylene (LDPE), linear low density polyethylene (LLDPE), medium density polyethylene (MDPE) and high density polyethylene (HDPE).
delete The method according to claim 1,
Wherein the packaging bag is selected from the group consisting of paper, coated paper, paper containing a liner film, film, yarn woven, and cloth.
The method according to claim 1,
Wherein the electron beam is irradiated to the packaging bag on one side or on both sides.
The method according to claim 1,
Wherein at least one additive selected from the group consisting of an antioxidant, a slip agent, an antiblocking agent, a UV stabilizer and a reaction aid is further injected into the inside of the packaging bag.
11. The method of claim 10,
Wherein the antioxidant is a non-phenolic antioxidant.