JP2012052039A - Polyolefin-based resin composition having thermal adhesivity with dissimilar material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermally adhesive resin composition exhibiting a high adhesive power to any of polyester, polyamide, an ethylene vinyl alcohol copolymer, and a metal foil (for example, Al foil), with no need of as high a temperature as exceeding 240°C and with no ozone treatment and nor oxygen treatment.SOLUTION: The composition is a polyolefin-based resin composition having a thermal adhesivity with a dissimilar material and obtained as follows. A graft copolymer (A) of an α-olefin and a dicarboxylic acid obtained by ring opening an unsaturated dicarboxylic anhydride monomer part of a graft copolymer (E) obtained by graft polymerizing the monomer to a poly(α-olefin), and a polyolefin composition (C) obtained by melting and kneading 0.05 to 5 pts.wt. of a compound (B) having ≥2 and ≤10 epoxy groups in the molecule with respect to 100 pts.wt. of a polyolefin (D) are mixed and melting and kneading in a weight ratio of (A)/(C)=2/98 to 40/60.

Description

  The present invention relates to a polyolefin resin composition having thermal adhesiveness with different materials. More specifically, the present invention relates to a polyolefin resin composition that can be used as a compatibilizing agent in the case of forming an adhesive layer in the case of multilayer coextrusion molding or multilayer lamination processing of a different material that is incompatible with polyolefin, and multilayer lamination. Is.

Polyolefins are nonpolar hydrocarbons that are not compatible with polar dissimilar materials (polyamide, polyester, ethylene-vinyl alcohol copolymer, metal foil, etc.), and multilayer molding (multilayer cast film formation, It is known to use an adhesive resin composition having a polar group in order to form a multilayer inflation film formation, multilayer blow molding, etc.) or a mixture, and it is also generally used industrially.

  Examples of polar groups introduced into these adhesive resins include carboxylic acids, dicarboxylic acid anhydrides, glycidyl compounds, and the like, and they have thermal adhesiveness with the different materials.

  However, the thermal adhesiveness between a commercially available adhesive resin and polyester is not yet sufficient, and various inventions for improving adhesiveness have been devised.

  In Patent Document 1, an adhesive resin composition of a polyolefin (a), a compound (b) having two or more epoxy groups in the molecule, and an olefin polymer (c) having a functional group that reacts with the epoxy group is devised. Has been.

  In the present invention, in order to exhibit effective adhesiveness, it is preferable to mold at a high temperature of 240 to 340 ° C. Not only can the production energy cost be increased, but the adhesive resin composition layer and the polyolefin layer are Since the viscosity is lowered by high temperature, the melt tension at the time of molding is insufficient, and problems such as drawdown are likely to occur. Although ozone treatment and oxygen treatment are recommended for low-temperature molding, special equipment must be introduced.

  In Patent Document 2, a polyolefin layer composed of a polyolefin (a), a compound (b) having two or more epoxy groups in the molecule, an olefin polymer (e) having a functional group that reacts with the epoxy group, a polyamide ( c) A direct adhesion laminate of a base material layer composed of an olefin polymer (d) having a functional group that reacts with an amino group has been devised.

  Also in this invention, in order to exhibit effective adhesiveness, it is preferable to mold at a high temperature of 240 to 340 ° C., and the production energy cost cannot be denied.

  Furthermore, this invention was made for the first purpose of improving the adhesiveness with polyamide, and a great effect on improving the adhesiveness with other dissimilar substrates, particularly polyester, cannot be expected.

JP-A-8-188679 JP-A-11-58633

  As described above, it is difficult to mold a resin composition that improves adhesion to dissimilar materials, particularly polyester, at high temperatures or without special equipment such as ozone treatment or oxygen treatment.

  Further, none of the polyesters, polyamides, ethylene-vinyl alcohol copolymers, and metal foils, which are mainly cited as different materials, have a resin composition having the same high adhesive strength.

  The object of the present invention is not required to be a high temperature exceeding 240 ° C., and polyester, polyamide, ethylene-vinyl alcohol copolymer, metal foil (for example, Al foil) can be used without performing ozone treatment or oxygen treatment. It is an object of the present invention to provide a heat-adhesive resin composition having high adhesive strength.

The present invention has been made to solve the above problems,
Graft copolymer of α-olefin and dicarboxylic acid obtained by ring-opening the monomer part of graft copolymer (E) obtained by graft polymerization of unsaturated dicarboxylic acid anhydride monomer to poly (α-olefin) ( A) and
Polyolefin composition (C) obtained by melting and kneading 0.05 to 5 parts by weight of compound (B) having 2 to 10 epoxy groups in the molecule with respect to 100 parts by weight of polyolefin (D) The
The graft copolymer (A) and the polyolefin composition (C) are mixed in a weight ratio of (A) / (C) = 2/98 to 40/60 and different materials obtained by melt-kneading. This object is achieved by the polyolefin resin composition having thermal adhesive properties.

  The resin composition of the present invention does not require special equipment such as ultra-high temperature molding, ozone treatment or oxygen treatment, and in addition to polyolefin (polyethylene, polypropylene, etc.), polyester, polyamide, ethylene- Both the vinyl alcohol copolymer and the metal foil have the same level of high thermal adhesive strength and are incompatible with polyolefins. It is possible to provide a uniform mixed composition with the dissimilar materials that are compatible. The resin composition of the present invention further exhibits adhesion to polybutylene terephthalate (PBT), polyvinyl alcohol, and the like.

  The graft copolymer (E) obtained by graft polymerization of an unsaturated dicarboxylic anhydride monomer to the poly (α-olefin) of the present invention will be described.

  Examples of α-olefin include ethylene or propylene, and poly (α-olefin), which is a homopolymer or a copolymer thereof, is a catalyst (Ziegler catalyst: for example, silica) obtained from a transition metal compound and an organoaluminum compound. Obtained by homopolymerization or copolymerization of olefins using a catalyst system (Phillips catalyst) obtained by supporting a chromium compound (eg, chromium oxide), or a radical initiator (eg, organic peroxide). . For this, commercially available polyethylene, polypropylene, and ethylene-polypropylene copolymer can be used.

The unsaturated dicarboxylic acid anhydride monomer used in the present invention is a compound having a cyclic anhydride (group) having at least one double bond and consisting of two carboxylic groups, Specific examples include maleic anhydride, phthalic anhydride, itaconic anhydride, citraconic anhydride, mesaconic anhydride, fumaric anhydride, and the like.
In particular, maleic anhydride and phthalic anhydride are preferred compounds from the viewpoint of heat resistance stability during resin processing and low adverse effects on the human body.

  The ratio of the α-olefin to the unsaturated dicarboxylic acid anhydride monomer is suitably 0.01 to 20 parts by weight of the unsaturated dicarboxylic acid anhydride monomer with respect to 100 parts by weight of the α-olefin.

The graft copolymer (E) obtained by graft-polymerizing an unsaturated dicarboxylic acid anhydride monomer to poly (α-olefin) specifically refers to a graft copolymer of unsaturated monomers onto the polyolefin. Graft copolymerization is poly (α-olefin)
To 100 parts by weight, 0.01 to 20 parts by weight of unsaturated monomer, preferably 0.05 to 3 parts by weight, 0.001 to 20 parts by weight of organic peroxide, preferably 0.005 to 0.05 parts by weight are added. The obtained mixture is fed to an extruder and melted and reacted.

  Representative examples of the organic peroxide used in the present invention include t-butyl peroxybenzoate, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, and di-t-butyl peroxide. It is done. Among the organic oxides, those having a half-life of 100 to 280 ° C. per minute are desirable, and those having a half-life of 120 to 230 ° C. are particularly preferable. This half-life can be measured by iodine titration by sealing a peroxide in a pressure vessel and taking a certain temperature and a certain time. These organic peroxides may be used alone or in combination of two or more.

If the blend of the unsaturated dicarboxylic acid anhydride monomer is less than 0.01 parts by weight with respect to 100 parts by weight of poly (α-olefin), the adhesion between the resin composition of the present invention and the dissimilar material is poor. On the other hand, when the amount exceeds 20 parts by weight, not only the unreacted or homopolymerized unsaturated compound remains in the graft reaction because the graft reaction efficiency is lowered, but the physical properties inherent to the polyolefin are impaired.

  Moreover, if the blending ratio of the organic peroxide to 100 parts by weight of poly (α-olefin) is less than 0.001 part by weight, a satisfactory graft copolymer cannot be obtained. On the other hand, if it exceeds 20 parts by weight, the physical properties inherent to poly (α-olefin) are impaired.

  Such a mixture is put into an ordinary extruder, melted and kneaded therein, and a graft reaction proceeds, whereby a graft-modified product is obtained. At this time, the extruder used may be either a non-vented type or a vented type, but from the viewpoint of removing unreacted or homopolymerized unsaturated compounds and decomposition products of organic peroxides, a vented type extruder is used. Is desirable. The kneading temperature is 180 to 250 ° C., and is preferably 190 to 230 ° C., although it varies depending on the types of poly (α-olefin), unsaturated dicarboxylic acid anhydride monomer and organic peroxide used. The residence time in the extruder is 60 seconds or longer, and particularly 90 seconds or longer is preferable. The upper limit is not particularly limited, but is preferably up to 180 seconds for practical use. When the kneading temperature is less than 180 ° C., the graft reaction is not performed well. On the other hand, when the temperature exceeds 250 ° C., a part of the poly (α-olefin) is deteriorated, and depending on the unsaturated dicarboxylic acid anhydride monomer, the decomposition temperature is exceeded and thermal deterioration occurs. When the residence time in the extruder is less than 60 seconds, a satisfactory graft reaction cannot be performed.

  There is a commercially available graft copolymer obtained by graft-polymerizing an unsaturated dicarboxylic acid anhydride monomer to poly (α-olefin), and this can be used.

  The copolymer (A) of α-olefin and dicarboxylic acid obtained by ring-opening the monomer portion of the graft copolymer (E) will be described.

  In the copolymer (E), a dicarboxylic acid anhydride part having a cyclic structure is usually ring-opened by a hydrolysis reaction in advance to obtain a copolymer (A) of an α-olefin and a dicarboxylic acid. The hydrolysis reaction proceeds by keeping the copolymer (E) at 30 to 80 ° C., preferably 40 to 60 ° C., in an environment of 50 to 100% RH for 5 hours or more. Thereby, for example, 95% or more of the dicarboxylic anhydride portion is ring-opened.

  The compound (B) having 2 to 10 epoxy groups in the molecule of the present invention will be described.

  The most preferred specific example is a higher fatty acid ester having a polyfunctional epoxy group, and examples thereof include epoxidized vegetable oils such as epoxidized soybean oil and epoxidized linseed oil.

  Another preferred specific example is a copolymer of a compound having an olefin group and glycidyl (meth) acrylate. The olefin group is an ethylene group, a propylene group, a styrene group or the like, and specifically, styrene-methyl (meth) acrylate-glycidyl methacrylate copolymer, ethylene-glycidyl methacrylate copolymer, ethylene-methyl acrylate. -Glycidyl methacrylate copolymer. All of these are commercially available and can be used. What is commercially available as a styrene-methyl (meth) acrylate-glycidyl methacrylate copolymer is JONCRYL (registered trademark) manufactured by BASF Japan Ltd. having 4 to 10 epoxy groups, and Toa Gosei Co., Ltd. having 2 epoxy groups. Examples include Alfon (registered trademark).

What is marketed as an ethylene-glycidyl methacrylate copolymer is Bond First (registered trademark) manufactured by Sumitomo Chemical Co., Ltd.
Examples of commercially available ethylene-methyl acrylate-glycidyl methacrylate copolymers include Lexpearl RB (registered trademark) manufactured by Nippon Polyethylene Corporation.

The polyolefin (D) of the present invention will be described.
Specific examples of the polyethylene include commercially available low density polyethylene, linear low density polyethylene, and high density polyethylene. Examples of the polypropylene include commercially available homopolymers, block copolymers, and random copolymers. As an example, when performing multilayer film formation according to the present invention, polyethylene has a MFR at 190 ° C. within a range of 0.50 to 10.00 g / 10 minutes, and polypropylene has a MFR at 230 ° C. of 0.50. It is preferred to use materials in the range of ~ 10.00 g / 10 min.

  The polyolefin composition (C) is 0.05 to 5 parts by weight, preferably 0, of the compound (B) having 2 to 10 epoxy groups in the molecule with respect to 100 parts by weight of the polyolefin (D). Obtained by melting and kneading 5 to 3 parts by weight. When the compound (B) is less than 0.05 parts by weight, the preliminary reaction effective for heat bonding is insufficient, and when it exceeds 5 parts by weight, the compound (B) exhibits an excessive lubricant action in the melt extruder, and the moldability is high. descend. After mixing (D) and (B) with the above composition, the mixture is put into a normal extruder and melt-kneaded therein to obtain the composition (C). At this time, the extruder to be used may be either a non-vented type or a vented type, but a vented type extruder is preferable in terms of removing unreacted or homopolymerized (B). Further, the kneading temperature is preferably 180 to 250 ° C., and the kneading time is preferably 120 to 180 seconds.

  The polyolefin-based resin composition having thermal adhesiveness with a different material of the present invention is a (A) / (C) = 2/98 to a graft copolymer (A) and a polyolefin composition (C) in a weight ratio. It is obtained by mixing and melting and kneading within a range of 40/60, preferably 5/95 to 30/70.

The graft copolymer and the melt flow rate of (A) _{(MFR -A),} the ratio of the polyolefin composition (C) of the melt flow rate _{(MFR -C)} is
MFR- _A / MFR- _C > 1.5
It is. This ratio is measured at 230 ° C. for the PP system and 190 ° C. for the PE system. When the ratio is less than 1.5, both (A) and (C) tend to be uniformly dispersed, and the polar groups present at the interface with the different material at the time of thermal bonding are diluted so that efficient bonding does not appear. The maximum ratio is not particularly limited, but, for example, about 10 is practical.

The melt kneading of (A) and (C) may be performed in advance before molding with a different material, or may be performed simultaneously with molding with a different material.
The extruder used for this melt-kneading may use either a non-vent type or a vent type. The kneading temperature is 180 to 250 ° C., and is preferably 190 to 230 ° C., although it varies depending on the type of polyolefin used. The residence time in the extruder is 60 seconds or longer, and particularly 90 seconds or longer is preferable. The upper limit is not particularly limited, but is preferably up to 180 seconds for practical use.

  The polyolefin resin composition of the present invention can contain a third component for various purposes within a range not impairing the purpose of the present invention.

  The resin composition of the present invention can be molded and used at 190 to 210 ° C., preferably 200 to 200 ° C. for the PE system, and 190 to 240 ° C., preferably about 200 to 230 ° C. for the PP system.

  The resin composition of the present invention obtained by melt-kneading (A) and (C) can be formed as a film. Examples of the film forming method include a general inflation method and a T-die method for forming a resin film. When the film-formed film is thermally bonded to the dissimilar material film, it is more preferable to perform a corona discharge treatment at the time of forming the resin composition film or immediately before the heat bonding. The corona discharge treatment amount is preferably 39 to 55 dyne / cm in terms of the wetting index of the film surface immediately after the treatment.

The present invention will be described more specifically with reference to examples.
The following resins were used.
PP: Polypropylene, made by Sun Allomer, “PB370A”
Density = 0.90 g / cm ³ , MFR = 1.3 g / 10 min AD-PP: maleic anhydride grafted polypropylene,
ZELAS “MC721AP” manufactured by Mitsubishi Chemical
Density = 0.90 g / cm ³ , MFR = 3.5 g / 10 minutes AD-PP1: The AD-PP was previously placed in an environment of 50 ° C. and 70% RH for 8 hours,
Maleic acid graft with acid anhydride ring-opened by standing
Polypropylene PE: Harmolex “NF324A” made of linear low density polyethylene and Japanese polyethylene
Density = 0.006 g / cm ³ , MFR = 0.9 g / 10 min AD-PE: maleic anhydride grafted polyethylene,
Modic “M545” manufactured by Mitsubishi Chemical
Density = 0.90 g / cm ³ , MFR = 6.0 g / 10 min AD-PE1: The AD-PE was previously placed in an environment of 50 ° C. and 70% RH for 8 hours,
Maleic acid graft with acid anhydride ring-opened by standing
Polyethylene ESO: Epoxidized soybean oil, Kapox Kapox, “S-6” (epoxy group number: 2 to 10 / molecule)
EPOXY: Styrene-methyl (meth) acrylate-glycidyl methacrylate
Copolymer, JONCRYL manufactured by BASF Japan Ltd.,
"ADR-4300S" (epoxy group number: 7-10 / molecule)
Substrate 1: Stretched nylon film, Harden film manufactured by Toyobo, “N1102”,
Thickness 15μm
Substrate 2: Stretched PET film, Toyobo ester film, “E5102”,
Thickness 12μm
Adherent 3: ethylene-vinyl alcohol copolymer film, eval film,
"EF-CR", thickness 15μm

<Formation of single-layer adhesive film>
While melt-kneading the mixture of the α-olefin and dicarboxylic acid graft copolymer (A) and the polyolefin composition (C), which have been previously opened, using a single-layer air-cooled inflation film forming machine under the following conditions: A single layer film having a thickness of 80 μm was obtained.
-Screw extruder with an outer diameter of 55 mm and a compression ratio of 2.7 (extrusion temperature 210 ° C.)
Die: Outer diameter 200mm, Lip spacing 3mm, Temperature 210 ° C
Blow ratio: 1.8
The film forming speed was 13 m / min and the corona discharge treatment was performed immediately before winding of the film forming process, and the output was adjusted so that the wetting index of the film surface immediately after the treatment was 43 to 52 dyne / cm.

<Preparation of adhesive specimen>
The heat bonding of the single layer film and the adherend film takes 0.5 seconds by laminating two films between a metal roll heated to a predetermined temperature and a rubber support roll installed in a gap of 0.1 mm. An adhesive specimen was obtained by passing through a crimp.

<Measurement of adhesive strength>
The adhesive strength of the produced adhesive specimen was measured according to JIS Z-1707.
The results obtained are shown in the table.

  The resin composition of the present invention has the same level of high thermal adhesive force as polyester, polyamide, ethylene-vinyl alcohol copolymer, and metal foil, and is a multilayer of the dissimilar material that is incompatible with polyolefin. A co-extruded product, a multilayer laminate product, or a uniform mixed composition of the dissimilar material that is incompatible with polyolefin can be provided.

Claims (6)

Graft copolymer of α-olefin and dicarboxylic acid obtained by ring-opening the monomer part of graft copolymer (E) obtained by graft polymerization of unsaturated dicarboxylic acid anhydride monomer to poly (α-olefin) ( A) and
Polyolefin composition (C) obtained by melting and kneading 0.05 to 5 parts by weight of compound (B) having 2 to 10 epoxy groups in the molecule with respect to 100 parts by weight of polyolefin (D) The
The graft copolymer (A) and the polyolefin composition (C) are mixed in a weight ratio of (A) / (C) = 2/98 to 40/60 and different materials obtained by melt-kneading. A polyolefin resin composition having thermal adhesive properties.   A polyolefin resin film having thermal adhesiveness with a different material obtained by melt-forming the polyolefin resin composition according to claim 1.   The compound (B) having 2 or more and 10 or less epoxy groups in the molecule is a higher fatty acid ester or a styrene-methyl (meth) acrylate-glycidyl methacrylate copolymer. The polyolefin resin composition according to 1.   The compound (B) having 2 or more and 10 or less epoxy groups in the molecule is a higher fatty acid ester or a styrene-methyl (meth) acrylate-glycidyl methacrylate copolymer. The polyolefin resin film according to 2. Graft copolymer at the same temperature as the melt flow rate (A) _{(MFR -A),} the ratio of melt flow rate of the polyolefin composition (C) _{(MFR -C),}
MFR- _A / MFR- _C > 1.5
The polyolefin resin composition according to claim 1 or 3, wherein Graft copolymer at the same temperature as the melt flow rate (A) _{(MFR -A),} the ratio of melt flow rate of the polyolefin composition (C) _{(MFR -C),}
MFR- _A / MFR- _C > 1.5
The polyolefin resin film according to claim 2 or 4, wherein