KR20000073751A - Adhesive polyolefin compounds - Google Patents

Abstract

PURPOSE: A heat adhesive polyolefin resin composition having excellent durability even under various weather conditions and impact conditions by adding impact resistance to characteristics of conventional heat adhesive polyolefin resin compositions is provided which has excellent adhesive capacity to a polar polymer such as other polyolefin resins, nylons, polyesters, ethylenevinyl alcohol copolymer or to a polar or a nonpolar substrate. CONSTITUTION: The heat adhesive polyolefin resin composition comprises 5 to 30% by weight of a high density polyethylene copolymer grafted 0.25 to 5% by weight of at least one ethylene unsaturated carboxylic acid or ethylene unsaturated carboxylic acid anhydride or ethylene unsaturated carboxylic acid ester monomer based on the high density polyethylene copolymer, 40 to 85% by weight of linear low density polyethylene and 10 to 30% by weight of hydrogenated styrenebutadiene block copolymer having a density of 0.89 to 0.91 g/cm¬3 and a melt index of 0.5 to 50 g/10min.

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 continuous 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-kneading graft copolymer grafted to one or two or more polymers of homo polypropylene, random polypropylene, block polypropylene, ethylene-propylene-diene copolymer, linear low density polyethylene and hydrogenated styrene-butadiene block copolymer To prepare a heat-adhesive polyolefin resin composition.

The heat-adhesive polyolefin resin composition of the present invention comprises (1) 0.25-5% by weight 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. 5 to 30% by weight of high density polyethylene (2) 40 to 85% by weight of linear low density polyethylene having a density range of 0.90 to 0.94 g / cm ^ 3 (3) 10 to 30% by weight of hydrogenated styrene-butadiene block copolymer do.

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% by weight, more preferably 0.5 to 2.5% by weight based on the entire base resin, and the graft reaction initiator is 0.001 to 1.0% by weight, more preferably 0.005 to the total base resin. Add 0.5% by weight. 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% by weight, it is difficult to impart adhesion performance. When the content of the grafting monomer is greater than 5.0% by weight, the reaction efficiency decreases, discoloration occurs severely, and unreacted monomers remain excessive.

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

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% by weight. When the grafted high-density polyethylene is less than 5% by weight, the adhesion with the adherend is hardly shown. When the grafted high density polyethylene exceeds 30% by weight, the increase in the adhesion 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% by weight. When the hydrogenated styrene-butadiene block copolymer is less than 10% by weight, the effect of improving impact resistance is hardly exhibited, and when the hydrogenated styrene-butadiene block copolymer is more than 30% by weight, the compatibility between the hydrogenated styrene-butadiene block copolymer and other compositions is worsened and the adhesion is lowered. In the preparation of the final composition of the invention there is a problem that the granulation process of the extrusion composition is unstable and productivity is lowered. Unmodified linear low density polyethylene is used in the composition of the present invention in the remaining 100% by weight based on the total weight of the grafted high density polyethylene and hydrogenated styrenebutadiene block copolymer.

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

2.0 wt% maleic anhydride and 0.1 wt% bis (t-butyl peroxy isopropyl) benzene were added to the Henschel mixer based on high density polyethylene (density 0.957 g / cm ^ 3, melt index 20 g / 10 min, Samsung General Chemical). Rotate at 200rpm for 2 minutes and evenly coat the surface of the high density polyethylene, then continuously extrude it using a twin-screw extruder (44mmψ, Japan JSW) to make maleic anhydride grafted at 0.5 wt% or more. / 10 min) copolymers were prepared.

The graft copolymer and linear low density polyethylene (density 0.935g / cm ^ 3, melt index 9.0g / 10min, Samsung General Chemical), hydrogenated styrene-butadiene block copolymer (styrene content = 20%, density 0.89g / cm ^ 3, melt index 13.0g / 10min, Japan Asahi Chemical) was mixed in a tumble mixer to the ratio shown in <Table 1>, and then melt kneaded at a temperature range of 160-220 ° C. in a twin screw extruder (44 mmψ, Japan JSW). To prepare a heat-adhesive polyolefin resin composition. 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-sealed 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 a tensile tester (INSTRON) by the method of ASTM D1876, and the adhesion was expressed in kgf as the load applied to 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 0.935g / cm ^ 3, melt index 9.0g / 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) is mixed in a tumble mixer to the ratio 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. The composition was prepared.

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 (% by 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 (% by 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 Adhesive force (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 above 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, thereby improving the adhesive strength of the heat-adhesive polyolefin resin composition. 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 high-density polyethylene copolymer in which at least 1 type of ethylenically unsaturated carboxylic acid, ethylenically unsaturated carboxylic anhydride, or ethylenically unsaturated carboxylic ester monomer is grafted 0.25 to 5 weight% based on the high density polyethylene copolymer. %, 40 to 85% by weight of linear low density polyethylene, 10 to 30% by weight of hydrogenated styrene-butadiene block copolymer, the heat-adhesive polyolefin resin composition. 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.