JPH08301944A - Modified polyolefin and its production - Google Patents

Abstract

PURPOSE: To obtain a modified polyolefin having a good long-term storage stability and being tightly bondable to a polar material containing hydroxyl, amino, carboxyl, imino, mercapto or acid anhydride groups at low temperature within a short time. CONSTITUTION: A modified polyolefin prepared by grafting 0.001-1.5mol% unsaturated isocyanate compound onto a polyolefin is reacted with a mixture comprising 100 pts.wt. polyolefin, 0.01-10 pts.wt. unsaturated isocyanate compound and 0.001-0.18 pt.wt. organic peroxide in an extruder to produce a modified polyolefin. Because the produced polyolefin can be tightly bonded to a polar material containing hydroxyl, amino, carboxyl, imino, mercapto or acid anhydride groups at low temperature within a short time, it is possible to produce a laminate of a polyolefin with the polar material by using their bondability.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a modified polyolefin having excellent adhesiveness and a method for producing the same. More specifically, it has excellent adhesiveness with a polar material containing a hydroxyl group, an amino group, a carboxyl group, an imino group, a mercapto group, an acid anhydride and the like, and a laminate using the adhesion between the polyolefin and the polar material. The present invention relates to a modified polyolefin which enables the production of

[0002]

2. Description of the Related Art Polyolefin is a resin that has excellent mechanical properties, thermal properties, chemical properties, electrical properties, etc., is easy to process, and is an inexpensive resin. It's being used. However, since it is a non-polar resin in terms of its chemical structure, it has excellent adhesiveness when producing a laminate with a polar material containing a polar group such as a hydroxyl group, an amino group, a carboxyl group, an imino group, a mercapto group, and an acid anhydride. It had the drawback of being scarce. Therefore, various methods for imparting adhesiveness have been developed.

As a typical method thereof, an unsaturated compound having a polar group such as an acid anhydride, a carboxyl group or an epoxy group in a polyolefin main chain is modified by graft copolymerization such as a solution method, a suspension method or a melting method. And a method of copolymerizing an olefin monomer with an acid anhydride, an unsaturated compound having a polar group such as a carboxyl group or an epoxy group, and the like. According to this method, the adhesiveness with a polar material containing a hydroxyl group, an amino group, a carboxyl group, an acid anhydride or the like is imparted without impairing the above-mentioned properties originally possessed by polyolefin. However, the conventional adhesion reaction rate between the modified polyolefin and the polar material is slow, and a high adhesion reaction temperature or a long adhesion reaction time is required to obtain sufficient adhesion.

Also known is a method of grafting an isocyanate group-containing unsaturated compound having high reactivity onto a polyolefin main chain in a solvent (JP-A-1-319507). The free radical initiator used in this method is polyolefin 1
It is 0.2 to 40 parts by weight with respect to 00 parts by weight, and the obtained modified polyolefin is expected to be effective as a multifunctional additive in lubricating oil, but from the viewpoint of adhesiveness with polar materials. Not only is the physical properties inherent in the polyolefin impaired, but also the grafted isocyanate groups are excessive, so sufficient adhesiveness cannot be obtained due to deactivation of the isocyanate groups during long-term storage.

Further, a method of copolymerizing ethylene and an unsaturated compound containing an isocyanate group (JP-A-2-300217).
However, since the adhesive functional group is present in the main chain, the molecular mobility of the adhesive functional group is limited compared to the graft type, and sufficient adhesiveness at low temperature and short time can be obtained. It has the drawback of not being.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a modified polyolefin which has good long-term storability and is capable of strong adhesion to polar materials at low temperature and in a short time, and a method for producing the same.

[0007]

Means for Solving the Problems The above-mentioned problems are (1) the addition of an isocyanate group-containing unsaturated compound to polyolefin.
001 to 1.5 mol% grafted modified polyolefin, (2) 100 parts by weight of (A) polyolefin, (B)
A mixture of 0.01 to 10 parts by weight of an unsaturated compound containing an isocyanate group and 0.001 to 0.18 parts by weight of (C) an organic peroxide is reacted in an extruder to produce a modified polyolefin of (1). It is solved by the method. The present invention will be described in detail below.

(A) Polyolefin The polyolefin used in the present invention includes ethylene homopolymer, propylene homopolymer, butylene homopolymer, ethylene / α-olefin copolymer, and propylene / α-olefin. And the like.

The molecular weight of these polyolefins is generally 10,000 to 1,000,000, preferably 20,000 to 500,000, and particularly preferably 50,000 to 300,000.

The shape of the polyolefin may be either powder or pellets, but from the viewpoint of enhancing dispersibility and modification efficiency, a shape having a large surface area, that is, powder is preferable.

These polyolefins are a catalyst system (Ziegler catalyst) obtained from a transition metal compound and an organoaluminum compound, or a catalyst obtained by supporting a chromium compound (eg, chromium oxide) on a carrier (eg, silica). It can be obtained by homopolymerization or copolymerization of olefins using a system (Phillips catalyst) or a radical initiator (for example, organic peroxide).

(B) Isocyanate Group-Containing Unsaturated Compound The isocyanate group-containing unsaturated compound used in the present invention has at least one double bond and at least one isocyanate group (--NCO). It is the compound contained.

Specifically, (meth) acryloyl isocyanate, crotoyl isocyanate, crotonic acid isocyanatoethyl ester, crotonic acid isocyanatobutyl ester, crotonic acid isocyanatoethylethylene glycol, crotonic acid isocyanatoethyldiethylene glycol, croton. Acid isocyanatoethyltriethylene glycol, (meth) acrylic acid isocyanatoethyl ester, (meth) acrylic acid isocyanatobutyl ester, (meth) acrylic acid isocyanatohexyl ester, (meth) acrylic acid isocyanatooctyl ester, (meth ) Acrylic acid isocyanato lauryl ester, (meth) acrylic acid isocyanato hexadecyl ester, (meth) acrylic acid isocyanato ethylene glycol Lumpur, it is preferable (meth) acrylic acid isocyanatoethyl diethylene glycol, (meth) acrylic acid isocyanatoethyl triethylene glycol and the like, especially (meth) acrylic acid isocyanatoethyl ester.

(C) Organic Peroxide The organic peroxide used in the present invention preferably has a one-minute half-life of 100 to 280 ° C., especially 1
Those having a temperature of 20 to 230 ° C. are preferable. As a typical example of the organic peroxide, t-butyl peroxybenzoate,
Examples include 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and di-t-butylperoxide. These organic peroxides may be used alone,
You may use 2 or more types together.

(D) Blending at the time of graft modification The blending amount of the unsaturated compound containing an isocyanate group is 0.01 to 10 parts by weight, preferably 0.02 to 5 parts by weight, and 0.05 to 100 parts by weight of the polyolefin. -5 parts by weight are particularly preferred. The amount of the unsaturated compound containing an isocyanate group added to 100 parts by weight of the polyolefin was 0.1.
If it is less than 01 parts by weight, the modified polyolefin has poor adhesion. On the other hand, if the amount exceeds 10 parts by weight, the graft reaction efficiency decreases, and thus the unreacted or by-product homopolymerized isocyanate group-containing unsaturated compound remains in the modified polyolefin, resulting in a decrease in adhesiveness. Not only that, but the physical properties originally possessed by the polyolefin are impaired.

The blending amount of the organic peroxide with respect to 100 parts by weight of the polyolefin is 0.001 to 0.18 parts by weight, preferably 0.01 to 0.18 parts by weight, and more preferably 0.02 to 0. 15 parts by weight is preferred. When the content of the organic peroxide is less than 0.001 part by weight based on 100 parts by weight of the polyolefin, the modified polyolefin has poor adhesion. On the other hand, if the amount exceeds 0.18 parts by weight, not only the physical properties originally possessed by the polyolefin are impaired, but also the graft reaction efficiency is lowered, so that the unreacted or by-product homopolymerized isocyanate group-containing unsaturated Adhesion is reduced because the compound remains significantly in the modified polyolefin.

(E) Grafting Method (Modification Method) The modified polyolefin of the present invention is obtained by using an extruder used in the field of general synthetic resins and carrying out modification while melt-kneading. At this time, the extruder to be used may be either a non-vent type or a vent type, but the unreacted or by-product homopolymerized isocyanate group-containing unsaturated compound and the decomposition product of the organic peroxide are removed. From the above point, a vent type extruder is preferable.

The kneading temperature is 140 to 280.degree. C., preferably 180 to 230.degree. C., although it depends on the kinds of polyolefin and organic peroxide used. If the kneading temperature is lower than 140 ° C., the modification will not be performed well. On the other hand, 2
If it exceeds 80 ° C, some of the polyolefin is deteriorated.

The residence time in the extruder is preferably 60 seconds or longer, more preferably 90 seconds or longer. If the residence time in the extruder is less than 60 seconds, satisfactory modification will not occur.

At the time of melt modification, stabilizers, fillers (for example, mica, talc, glass, organic fibers, wood powder), lubricants and flame retardants, which are generally used in the field of polyolefin, are added. It may be added and used as a composite material.

The modified polyolefin produced by the above production method is obtained by grafting 0.001 to 1.5 mol% of an isocyanate-containing unsaturated compound on the polyolefin. When the graft amount of the isocyanate group-containing unsaturated compound is less than 0.001 mol%, the adhesiveness is poor,
If it exceeds 1.5 mol%, the adhesiveness will be poor.

The isocyanate group grafted to the modified polyolefin obtained by the above-mentioned modification method is one which chemically reacts with a polar material containing a hydroxyl group, an amino group, a carboxyl group, an imino group, a mercapto group, an acid anhydride or the like. It is conceivable that a strong bond will be possible.

[0023]

EXAMPLES Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The modified polyolefin used, the polar material as the adherend, and the method for measuring the peel strength are as follows.

(A) Modified polyolefin (GPE-1) melt flow rate (JIS-K-67)
Complies with 60. Note that the load is 2.16 kg / 1.0 g /
1.5 parts by weight of methacrylic acid isocyanatoethyl ester to 100 parts by weight of linear high-density polyethylene having a density of 0.945 g / cm ³ in 10 min.
0.15 parts by weight of 2,5-dimethyl-2,5-di (tertiary-butylperoxine) hexane was previously mixed using a Henschel mixer, and the resulting mixture was mixed with a 40 mmφ single screw extruder to obtain a resin temperature. Modified polyethylene grafted with methacrylic acid isocyanate ethyl ester obtained by melt-kneading at 220 ° C. The modified polyethylene (GPE-1) obtained had a melt flow rate of 0.2 g / 1.
It was 0 min.

(GPE-2) Melt flow rate (JI
Conforms to SK-6760. (The load is 2.16 kg)
Is 1.0g / 10min and the density is 0.945g / cm
^To 100 parts by weight of linear high-density polyethylene, which is ³ , methacrylic acid isocyanatoethyl ester 1.
5 parts by weight and 3.0 parts by weight of 2,5-dimethyl-2,5-di (tertiary-butylperoxine) hexane were mixed in advance using a Henschel mixer, and the resulting mixture was 40 mm.
Modified polyethylene grafted with methacrylic acid isocyanatoethyl ester obtained by melt-kneading at a resin temperature of 220 ° C. using a φ single screw extruder. The resulting modified polyethylene (GPE-2) had a melt flow rate that was too large to measure due to an excess of organic peroxide.

(GPE-3) Melt flow rate (JI
Conforms to SK-6760. (The load is 2.16 kg)
Is 1.0g / 10min and the density is 0.945g / cm
For a linear high density polyethylene 100 parts by weight ^3, 0.3 parts by weight of maleic anhydride, 2,5-dimethyl -
2,5-di (tertiary-butylperoxine) hexane 0.
01 parts by weight was previously mixed using a Henschel mixer,
Modified polyethylene grafted with maleic anhydride obtained by melt-kneading the obtained mixture at a resin temperature of 270 ° C. using a 40 mmφ single screw extruder. The obtained modified polyolefin (GPE-3) has a melt flow rate of 0.5.
It was g / 10 min.

(GPE-4) Melt flow rate (JI
Conforms to SK-6760. (The load is 2.16 kg)
Is 5.0g / 10min and the density is 0.945g / cm
Relative linear high density polyethylene 100 parts by weight is ^3, 0.6 parts by weight of glycidyl methacrylate, 2,5
0.04 parts by weight of dimethyl-2,5-di (tertiary-butylperoxine) hexane was previously mixed using a Henschel mixer, and the resulting mixture was melted at a resin temperature of 250 ° C. using a 40 mmφ single screw extruder. Modified polyethylene grafted with glycidyl methacrylate obtained by washing and removing unreacted and homopolymerized glycidyl methacrylate with acetone after kneading. The modified polyolefin (GPE-4) obtained had a melt flow rate of 2.8 g / 10 min.

(B) Adherend EVOH (Ethylene-Vinyl Alcohol Copolymer) An ethylene-vinyl alcohol copolymer having a melting point of 183 ° C. and an ethylene copolymerization ratio of 32 mol% (Eval EP-F101 manufactured by Kuraray Co., Ltd.). ) Was used. PA6 (Polyamide 6) Polyamide 6 (Amilan CM1061Y manufactured by Toray Industries, Inc.) having a melting point of 215 ° C. was used. PET (polyethylene terephthalate) A polyethylene terephthalate film (Lumirror manufactured by Toray Industries, Inc.) subjected to a biaxial stretching process was used.

(C) Method of Measuring Peel Strength The test pieces for the adhesion peel test used in the following Examples and Comparative Examples are modified polyolefins and heated at 190 ° C. in a hot press molding machine for 300 seconds under heating and 60 kg / cm ² under pressure. A press plate having a thickness of 1 mm was produced under the molding conditions described in 1. The adherend E
For the VOH and PA6 press plates, the heating temperature should be 22
It was prepared by the same operation except that the temperature was 0 ° C. However, as for the adherend PET, the film was used as it was. Two pieces of the above-mentioned modified polyolefin and the adherend were pressed by a hot press molding machine under various conditions and then cut into a width of 10 mm to obtain a laminated test piece. The peel strength was measured by a T-type peeling method using a tensile tester on the laminated test piece having a width of 10 mm at a speed of 50 mm / min.

(Examples 1 and 2) Modified polyolefin (G
A laminated test piece of PE-1) and an ethylene-vinyl alcohol copolymer (EVOH) was laminated with a hot press molding machine at an adhesion temperature of 160 ° C. (or 180 ° C.) and an adhesion time of 90 seconds.
It was produced under the condition of a pressure of 10 kg / cm ² . The peel strength was good as shown in Table 1.

(Comparative Examples 1 to 3) Modified polyolefin (G
GPE-2, GPE-3, GPE instead of PE-1)
-4 was used to produce a laminated test piece with an ethylene-vinyl alcohol copolymer (EVOH) under the conditions of a heat press molding machine at 180 ° C., a heating time of 90 seconds, and a pressure of 10 kg / cm ^2. However, the peel strength was low as shown in Table 1.

(Examples 3 and 4) Laminated test pieces were prepared by using polyamide 6 (PA6) instead of the ethylene-vinyl alcohol copolymer (EVOH) in Examples 1 and 2. The peel strength was good as shown in Table 1.

(Comparative Examples 4 to 6) Modified polyolefin (G
GPE-2, GPE-3, GPE instead of PE-1)
-4, a laminated test piece with polyamide 6 (PA6) was heated by a hot press molding machine at 180 ° C. for a heating time of 90 seconds,
Attempts were made under the conditions of a pressure of 10 kg / cm ² , but the peel strength was low as shown in Table 1.

Example 5 Modified Polyolefin (GPE)
-1) and polyethylene terephthalate laminated test pieces were heated by a hot press molding machine at 160 ° C. for a heating time of 180.
It was produced under the condition of a pressure of 10 kg / cm ² for seconds. The results of measuring the peel strength were good as shown in Table 1.

(Comparative Examples 7 to 9) Modified polyolefin (G
GPE-2, GPE-3, GPE instead of PE-1)
-4 is used, polyethylene terephthalate (PET)
An attempt was made to fabricate a laminated test piece of No. 1 by a hot press molding machine under the conditions of 160 ° C., heating time of 180 seconds and pressure of 10 kg / cm ² , but the peel strength was low as shown in Table 1. .

[0036]

[Table 1]

[0037]

The modified polyolefin of the present invention has a strong adhesive property at low temperature and short time with a polar material containing a hydroxyl group, an amino group, a carboxyl group, an imino group, a mercapto group, an acid anhydride and the like, It enables the production of a laminate using the adhesion between a polyolefin and the above polar material. As a result, it is possible to obtain a laminate using the adhesion of the modified polyolefin and the polar material, and it is possible to form a multi-layer plate, packaging material, container, or the like.

Claims (2)

[Claims] 1. A modified polyolefin obtained by grafting 0.001 to 1.5 mol% of an unsaturated compound containing an isocyanate group onto a polyolefin. 2. (A) 100 parts by weight of polyolefin,
(B) Isocyanate group-containing unsaturated compound 0.01 to 1
0 parts by weight, and (C) organic peroxide 0.001 to 0.
The method for producing a modified polyolefin according to claim 1, wherein a mixture of 18 parts by weight is reacted in an extruder.