KR100549709B1 - Adhesive polyolefin compounds - Google Patents

Abstract

5-30 weight of high density polyethylene copolymer in which ethylenically unsaturated carboxylic acid, its anhydride, or ester monomer thereof is 0.25-5 weight graft based on high density polyethylene copolymer, 40-85 weight of linear low density polyethylene, hydrogenated styrene-butadiene block air Heat-adhesive polyolefin resin composition, characterized in that composed of 10 to 30% by weight.

Polyolefin resin, impact resistance, adhesive

Description

Heat Adhesive Polyolefin Resin Composition

The present invention relates to a heat adhesive polyolefin resin composition, and more particularly to a heat adhesive polyolefin resin composition excellent in impact resistance and adhesion.

Industrial applications include coating the resin composition by powder fusion to prevent corrosion of steel springs for automobiles, steel springs for electric vehicles, marine steel structures, and the like. Applicable to all fields where impact properties are required.

Polyolefin resins are used for various purposes due to their light weight, low price, and excellent physical properties. However, since the polyolefin-based resin is nonpolar, its compatibility with polar substrates such as nylon, polyester, aluminum, iron, paper, wood, and the like is poor, and its use range has been limited.

In order to compensate for this problem, a number of patents and compositions for preparing polyolefins that enhance adhesion by chemically grafting polar groups on the polyolefin backbone have been published, but there are still many improvements.

U. S. Patent No. 4,612, 155 relates to a method for continuously grafting in the presence of a maleic anhydride bicomponent.

U. S. Patent No. 4,762, 890 discloses a method of dissolving maleic anhydride and an initiator in a solvent and injecting it into a twin screw extruder by means of a liquid injection device for grafting.

U.S. Patent 4,031,062 discloses a composition for enhancing adhesion by adding magnesium oxide to a polypropylene polymer grafted with maleic anhydride.

Korean Patent Publication No. 89-10078 discloses a composition prepared by adding ethylene vinyl acetate copolymer and polybutene.

Korean Patent Publication No. 96-7310 discloses a heat-adhesive polyolefin resin composition composed of high density polyethylene grafted with maleic anhydride, unmodified low density polyethylene, linear low density polyethylene, high density polyethylene, or polypropylene and an adhesive agent. have.

However, the adhesive resin manufacturing method of the United States Patent No. 4,762,890, United States Patent No. 4,031,062, Republic of Korea Patent Publication No. 89-10078 has a problem that the process is complicated and expensive manufacturing, Republic of Korea Patent Publication No. 96-7310 Although the manufacturing cost is lowered by simplifying the manufacturing process, there is a problem in that it is difficult to apply to a field in which adhesion performance is limited and impact resistance is required.

Therefore, the present invention is to solve the above problems and to provide a polyolefin resin composition through a simple manufacturing process.                         

In addition, the present invention is to provide a resin composition having excellent durability under various climate and impact conditions by imparting impact resistance to the properties of the conventional heat-adhesive polyolefin resin composition.

Furthermore, the present invention is to improve the adhesion of the conventional heat-adhesive polyolefin resin composition to be compatible with various substrates.

As described above, an object of the present invention is to provide adhesion between a nonpolar substrate such as polyolefin and a polar polymer such as nylon, polyester, and ethylene vinyl alcohol copolymer, or a polar substrate such as aluminum, iron, paper, wood, and glass by thermal fusion. It is an object of the present invention to provide a heat-adhesive polyolefin resin composition having improved and improved impact resistance according to the conditions of use of the finished product.

In order to achieve the above object, the present invention provides an impact resistance by optimizing the mixing ratio of ethylenically unsaturated carboxylic acid or its anhydride or ester monomer thereof, grafted high density polyethylene copolymer, linear low density polyethylene, and hydrogenated styrene-butadiene block copolymer. And a polyolefin resin composition having excellent adhesion.

Hereinafter, the present invention will be described in detail.

In the present invention, one or two or more ethylenically unsaturated carboxylic acids, ethylenically unsaturated carboxylic anhydrides or ethylenically unsaturated carboxylic ester monomers are reacted by low pressure polyethylene, linear low density polyethylene, high density polyethylene, Melt the graft copolymer grafted to one or two or more of the homopolypropylene, random polypropylene, block polypropylene, and ethylene-propylene-diene copolymers with linear low density polyethylene and hydrogenated styrenebutadiene block copolymers at a predetermined ratio. Kneading to prepare a heat-adhesive polyolefin resin composition.

The heat-adhesive polyolefin resin composition of the present invention comprises (1) 0.25-5 weight graft of one or two or more monomers in ethylenically unsaturated carboxylic acid, anhydrides of ethylenically unsaturated carboxylic acids or esters of ethylenically unsaturated carboxylic acids. It consists of 10-30 weight of linear low density polyethylene 40-85 weight (3) hydrogenated styrene-butadiene block copolymer which has a density range of 5-30 weight (2) 0.90-0.94g / cm <3> of high density polyethylene.

Examples of the carboxylic acid among the grafting monomers used in the present invention include ethacrylic acid, methacrylic acid, acrylic acid, maleic acid, fumaric acid, itaconic acid, and the like. Examples include glycidyl methacrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate, monoethyl maleate, diethyl maleate, di-normal-butyl maleate, and the like. In addition, examples of the ethylenically unsaturated carboxylic anhydride include maleic anhydride, dodecynyl succinic anhydride, 5-norbornene-2,3-anhydride, nadic anhydride or a polar compound having a similar chemical structure.

In order to graf the grafting monomer, a graft reaction initiator may be used in the present invention, and the graft reaction initiator may be acyl peroxide, dialkyl or aralkyl peroxide, peroxy ester, hydroperoxide, ketone peroxide. , One or more than one belonging to the group of azo compounds and the like can be selected. Examples of the acyl peroxides include benzoyl peroxide and the like. Examples of dialkyl or aralkyl-peroxides include di-t-butylperoxide, dicumylperoxide, cumyl butylperoxide, 1,1-di-t-butylperoxy-3,5,5, -trimethyl cyclohexane , 2,5-dimethyl-2,5, -dit-butylperoxyhexane, bis (t-butylperoxy isopropyl) benzene, and the like, and examples of the peroxy ester are t-butylperoxy pivalate , t-butyl di (perphthalate), dialkyl peroxy monocarbonate, peroxy dicarbonate, t-butyl perbenzoate, 2,5, -dimethyl hexyl-2,5-di (perbenzoate), t -Butyl peroctoate, etc. are mentioned. Examples of hydroperoxides include t-butylhydro peroxide, P-methane hydroperoxide, evacuation hydroperoxide, cumene hydroperoxide, and the like. Examples of ketone peroxides include cyclohexanone peroxide, methylethylketone peroxide, and the like. Moreover, azobis isobutyronitrile etc. are mentioned as an example of an azo compound.

In the present invention, the graft monomer is 0.25 to 5.0 weight, more preferably 0.5 to 2.5 weight based on the entire base resin, and the graft reaction initiator is added to 0.001 to 1.0 weight, more preferably 0.005 to 0.5 weight based on the entire base resin. do. In the present invention, other small amounts of additives such as antioxidants and paraffin wax may be used.

When the content of the grafting monomer is less than 0.25 weight, it is difficult to impart the adhesive performance, and when the content of the grafting monomer is more than 5.0 weight, problems such as deterioration of reaction efficiency, severe discoloration, and excessive unreacted monomer remain.

In addition, when the amount of the reaction initiator is less than 0.001 weight, the grafting reaction of the grafting monomer is difficult to occur, and when it exceeds 1.0 weight, the crosslinking reaction of the base resin occurs severely with the grafting reaction, resulting in poor melt flowability. Problems arise.

The grafted high-density polyethylene has a density of 0.93-0.98 g / cm ^ 3 and a melt index of 5-20 g / 10 min. The high density polyethylene grafted in the composition of the present invention is preferably 5 to 30 weight. When the grafted high-density polyethylene is less than 5 wt%, the adhesive force with the adherend is hardly shown. When the grafted high density polyethylene is more than 30 wt%, the increase in the adhesive force with the adherend does not occur anymore, and it is not economical.

The ungrafted unmodified linear low density polyethylene of the present invention has a melt index of 1.0 g / 10 minutes to 50 g / 10 minutes, and a hydrogenated styrene butadiene block copolymer has a density of 0.89 to 0.91 g / cm ^ 3 and a melt index of 0.5 to 50 g / 10 minutes.

The hydrogenated styrenebutadiene block copolymer in the composition of the present invention is preferably 10 to 30 weight. When the hydrogenated styrene-butadiene block copolymer is less than 10 wt%, the effect of improving impact resistance is hardly exhibited, and when the hydrogenated styrene-butadiene block copolymer is more than 30 wt%, the compatibility between the hydrogenated styrene-butadiene block copolymer and other compositions is worsened and the adhesion is lowered. When the final composition is prepared, there is a problem in that the granulation process of the extrusion composition is unstable and productivity is lowered. Unmodified linear low density polyethylene is used with the remaining weight relative to the total 100 weight depending on the weight of the grafted high density polyethylene and hydrogenated styrenebutadiene block copolymer in the composition of the present invention.

The graft polymer of the present invention is coated with a constant content of one or two or more of the graft monomer and a certain amount of the initiator in a Henschel mixer in a high-density polyethylene to continuously react and extrude in a twin screw extruder to produce a graft copolymer In this case, the residence time is maintained long enough for the grafting reaction to occur. Unreacted grafting monomer is removed using a vacuum at the end of the extruder.

Heat-adhesive according to the present invention by mixing the graft copolymer, linear low density polyethylene, hydrogenated styrene-butadiene block copolymer prepared as described above in a tumble mixer and melt kneading at a temperature of 160 ~ 220 ℃ in a single screw or twin screw extruder The polyolefin resin composition can be prepared.

Representative application structures of the composition of the present invention include polyamide / heat adhesive polyolefin resin / polypropylene, polyamide / heat adhesive polyolefin resin / polyethylene, polyester / heat adhesive polyolefin resin / polyethylene, metal / heat adhesive polyolefin Resin / Polyethylene, Epoxy Resin / Heat Adhesive Polyolefin Resin / Polyethylene, Aluminum / Heat Adhesive Polyolefin Resin / Polyethylene / Heat Adhesive Polyolefin Resin / Aluminum, Polyethylene / Heat Adhesive Polyolefin Resin / Aluminum / Heat Adhesive Polyolefin Resin / Polyethylene , Crosslinked polyethylene / heat adhesive polyolefin resin / aluminum / heat adhesive polyolefin resin / crosslinked polyethylene, polypropylene / heat adhesive polyolefin resin / polyester, paper / heat adhesive polyethylene, polyethylene / heat adhesive polyolefin resin / Glass, aluminum / heat adhesive polyolefin resin / metal, ethylene ratio And the like alcohol copolymer / polyolefin resin heat-adhesive / polypropylene.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, the scope of the present invention is not limited by the following examples.

Examples 1 to 3

2 parts of maleic anhydride and 2.0 parts of bis (t-butyl peroxy isopropyl) benzene were added to a Henschel mixer based on high density polyethylene (density 0.957g / cm ^ 3, melt index 20g / 10 minutes, Samsung General Chemical). Rotate at 200 rpm and evenly coat the surface of the high density polyethylene, and then use the twin-screw extruder (44mmψ, Japan JSW) to continuously extrude the high-density polyethylene (melt index 6.0 g / 10 min) with maleic anhydride grafted at 0.5 weight or more. Copolymers were prepared.

The graft copolymer and linear low density polyethylene (density 0.935 g / cm ^ 3, melt index 9.0 g / 10 minutes, Samsung General Chemical), hydrogenated styrene butadiene block copolymer (styrene content = 20, density 0.89 g / cm ^ 3 , Melt index 13.0g / 10min, Asahi Chemical, Japan) by mixing in a tumble mixer to the ratio shown in <Table 1>, and then melt kneaded at a temperature range of 160 ~ 220 ℃ in a twin screw extruder (44mm ψ, Japan JSW) A heat adhesive polyolefin resin composition was prepared. After preparing the adhesive force and Izod impact strength measurement specimen as described below, the adhesion and impact resistance was measured and the results are shown in Table 1.

[Adhesive Force Measurement Specimen Preparation]

A 50 μm film was prepared from the heat-adhesive polyolefin resin composition, and the substrate was placed on a 2 mm-thick linear low density polyethylene (0.921 g / cm ^ 3, melt index 0.9 g / 10 min) sheet and an adherend thereon, followed by 200 ° C. , And heat-bonded for 2 minutes at a pressure of 4 kg / cm ^ 2 and then cooled at room temperature, 1 kg / cm ^ 2 for 10 minutes and was cut into a width of 2.5cm, length 20cm.

[Adhesion Measurement]

T-Peel adhesion was measured in the tensile tester (INSTRON) by the method of ASTM D1876, and the adhesion was expressed as kgf of the peeling force with the adherend.

[Impact resistance measurement]

IZOD impact strength was measured at room temperature, 0 ℃, -10 ℃, -20 ℃, -30 ℃ by the method of ASTM D256.

Comparative Examples 1 to 6

Graft copolymer prepared by the method of Example 1 and linear low density polyethylene (density 0.935 g / cm ^ 3, melt index 9.0 g / 10 minutes, Samsung General Chemical), hydrogenated styrene butadiene block copolymer (styrene content = 20, Density 0.89g / cm ^ 3, Melt Index 13.0g / 10min, Japan Asahi Chemical), Ethylene Vinyl Acetate Copolymer (Vinyl Acetate Content = 22, Melt Index 3.0g / 10min, Samsung General Chemical), Ethylene Propylene Copolymer (Propylene content = 26, density 0.86g / cm ^ 3, melt index 3.2g / 10min, Kumho EP rubber), ethylene octene copolymer (density 0.87g / cm ^ 3, melt index 1.0g / 10min, Dupont Dow Elastomer) was mixed in a tumble mixer so that the ratio is shown in <Table 2>, and then melt kneaded in a twin screw extruder (44 mmψ, Japan JSW) at a temperature range of 160 to 220 ° C. to prepare a heat-adhesive polyolefin resin composition. It was.

The adhesion and impact resistance of the polyolefin resin composition prepared as described above were measured in the same manner as in Example, and the results are shown in <Table 2>.

division                                               Example 1  Example 2  Example 3   Composition (weight)  Graft copolymer  20  30  25  Linear Low Density Polyethylene  70  50  50  Hydrogenated Styrene Butadiene Block Copolymer  10  20  25  Adhesive force (kgf)  Adherend: iron  17.2  20.1  18.5  Adherend: aluminum  14.3  18.0  16.9  IZOD impact strength (kgcm / cm)  Room temperature  N B  N B  N B  0 ℃  N B  N B  N B  -10 ℃  N B  N B  N B  -20 ℃  47  N B  N B  -30 ℃  23  48  69

division                                               Comparative Example 1  Comparative Example 2  Comparative Example 3  Comparative Example 4  Comparative Example 5  Comparative Example 6   Composition (weight)  Graft copolymer  30  30  30  30  30  30  Linear Low Density Polyethylene  70  65  20  50  50  50  Hydrogenated Butadiene Block Copolymer  -  5  50  -  -  -  Ethylene Vinyl Acetate Copolymer  -  -  -  20  -  -  Ethylene Propylene Copolymer  -  -  -  -  20  -  Ethylene Octene Copolymer  -  -  -  -  -  20  Adhesion (kgf)  Adherend: iron   6.1   7.0  5.2  7.2  7.3   7.9  Adherend: aluminum   4.6   5.3  3.7  5.1  5.5   5.7  IZOD impact strength (kgcm / cm)  Room temperature  N B  N B  N B  N B  N B  N B  0 ℃   5   21  N B  35  N B  N B  -10 ℃   -   10  N B  15  30   33  -20 ℃   -   3  N B  2.4  5.5   24  -30 ℃   -  -  N B  -  2.7  12

As can be seen from the table, the heat-adhesive polyolefin resin composition of the present invention optimizes the composition of the polar monomer-grafted copolymer, the polyolefin resin and the hydrogenated styrene-butadiene block copolymer, compared to the conventional heat-adhesive polyolefin resin composition. Adhesion and impact resistance could be greatly improved.

Therefore, the heat-adhesive polyolefin resin composition of the present invention has greatly improved adhesion and impact resistance as compared with the existing heat-adhesive polyolefin resin composition, and is applicable to all fields requiring impact resistance of coatings when bonding various composite materials. It is possible. In particular, when powder-coated coating is used in areas requiring corrosion protection and impact resistance at the same time, such as steel springs for automobiles, steel springs for electric vehicles, marine steel structures, etc., the productivity and required characteristics of the product can be greatly satisfied.

In addition, the heat-adhesive polyolefin resin composition of the present invention is a polyolefin resin, nylon, or other polyolefin resin by heat fusion by a method such as co-extrusion, extrusion coating, circular die coating, T-die coating, powder coating, pressing, or the like. It has excellent adhesion with polar polymers such as polyester and ethylene vinyl alcohol copolymers and polar or non-polar substrates such as aluminum, iron, paper, wood, glass, etc., and can be applied as a coating or bonding material thereof.                     

Claims (7)

5-30 weight of the high-density polyethylene copolymer in which one or more ethylenically unsaturated carboxylic acid or ethylenically unsaturated carboxylic anhydride or ethylenically unsaturated carboxylic ester monomer is 0.25-5 weights grafted based on the high density polyethylene copolymer, A heat-adhesive polyolefin resin composition comprising 40 to 85 weight of linear low density polyethylene and 10 to 30 weight of hydrogenated styrene-butadiene block copolymer. The method of claim 1, The ethylenically unsaturated carboxylic acid is a heat-adhesive polyolefin resin composition, characterized in that one or two or more of etacrylic acid, methacrylic acid, acrylic acid, maleic acid, fumaric acid, or itaconic acid. The method of claim 1, The ethylenically unsaturated carboxylic anhydride is one or two or more of maleic anhydride, dodecynyl succinic anhydride, 5-norbornene-2,3- anhydride, or nadic anhydride. The method of claim 1, The ethylenically unsaturated carboxylic esters may be glycidyl methacrylate, 2-hydroxy ethyl acrylate, 2-hydroxy ethyl methacrylate, monoethyl maleate, diethyl maleate or di-normal-butyl maleate It is 1 or 2 or more in the heat-adhesive polyolefin composition. The method of claim 1, The high density polyethylene is a heat adhesive polyolefin resin composition, characterized in that the density of 0.93 ~ 0.98 g / cm ^ 3, the melt index of 5.0 to 20 g / 10 minutes. The method of claim 1, The linear low density polyethylene has a density of 0.90 to 0.94 g / cm ^ 3, a melt index of 1.0 to 50 g / 10 minutes, the heat-adhesive polyolefin resin composition. The method of claim 1, The hydrogenated styrene-butadiene block copolymer is a heat-adhesive polyolefin resin composition, characterized in that the density of 0.89 ~ 0.91 g / cm ^ 3, the melt index 0.5 ~ 50g / 10 minutes.