JPH0223567B2 - - Google Patents

Description

[Detailed description of the invention]

INDUSTRIAL APPLICATION FIELD The present invention relates to a method for producing a modified olefin polymer having excellent adhesion to various substances. More specifically, it contains as a monomer unit at least one α,β-ethylenically unsaturated carboxylic acid ester selected from the group consisting of acrylic acid alkyl ester and methacrylic acid alkyl ester, and a dibasic unsaturated carboxylic acid or a derivative thereof. The present invention relates to a method for producing a modified olefin-based polymer, which is characterized by treating an olefin-based multi-component copolymer with an unsaturated carboxylic acid or its derivative in the presence of a radical initiator. The purpose of this invention is to provide a modified olefin polymer that has good adhesion to (resins, metals, glass, wood). Conventional technology Olefin polymers (including copolymers) such as ethylene polymers and propylene polymers not only have excellent mechanical properties and physical properties such as water resistance, but also have good moldability. and
Furthermore, because it is inexpensive, it is used in a wide variety of fields. However, as shown in its chemical structure, this olefin polymer does not have a polar group in its molecule, so it is used in synthetic resins such as saponified ethylene-vinyl acetate copolymers and amide polymers, and metals. However, it has the disadvantage of extremely poor adhesion to different materials such as wood. For this reason, many attempts have been made to impart adhesive properties to olefinic polymers. As an improvement method, the surface of the olefinic polymer molded product can be roughened in advance by mechanical roughening, solvent treatment, electrical treatment (e.g., corona discharge treatment, plasma discharge treatment), flame treatment, acid treatment, etc. Treatment methods and surface treatment methods such as oxidation treatment using oxygen or ozone [edited by Kenzo Takagi and Heizo Sasaki, “Plastic Materials Course, Polypropylene Resin” (Nikkan Kogyo Shimbun, published in 1962)
Pages 216 to 219] and methods for copolymerizing olefins with vinyl monomers having polar groups, and grafting reactions of vinyl monomers having polar groups (e.g., unsaturated carboxylic acids, their anhydrides), etc. to olefin polymers. It has been proposed to introduce a polar group into the molecule of an olefinic polymer by a method, and some of these methods have been put to practical use. Recently, more severe usage conditions and molding conditions have been required, and there is a strong demand in the market for materials that have better adhesive properties under these conditions. However, it is difficult for any of the above-mentioned surface treatment methods, copolymerization methods, and graft reaction methods to fully satisfy the requirements. Problems to be Solved by the Invention In view of the above, the present invention does not have these drawbacks (problems), and in other words, it is a modified olefin polymer, especially a modified ethylene polymer, which has very strong adhesive strength with various substances. It is to obtain union. Means and Effects for Solving the Problems According to the present invention, these problems are solved by at least one α,β-ethylenically unsaturated carbonyl selected from the group consisting of alkyl acrylates and alkyl methacrylates. Acid esters 0.1-50% by weight and dibasic unsaturated carboxylic acids or derivatives thereof 0.05-20% by weight
The problem can be solved by a method for producing a modified olefinic polymer, which comprises treating an olefinic multi-component polymer containing as a monomer unit with an unsaturated carboxylic acid or a derivative thereof in the presence of a radical initiator. . The present invention will be explained in detail below. (A) Olefin-based multi-component copolymer The olefin-based multi-component copolymer of the present invention comprises at least one α,β-type ethylenically unsaturated carboxylic acid ester selected from the group consisting of acrylic acid alkyl esters and methacrylic acid alkyl esters; It is an olefin-based multi-component copolymer containing a basic unsaturated carboxylic acid or its derivative as a monomer unit. The number of carbon atoms in the alkyl group of the α,β-ethylenically unsaturated carboxylic acid ester is usually 1 to 10 (preferably 1 to 8), and among this α,β-ethylenically unsaturated carboxylic ester, Representative examples of acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate. Furthermore, representative examples of alkyl methacrylates include methyl methacrylate, ethyl methacrylate, and butyl methacrylate.
Among these α,β-ethylenically unsaturated carboxylic acid esters, methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate are particularly preferred. Further, among dibasic unsaturated carboxylic acids or derivatives thereof, the dibasic unsaturated carboxylic acid usually has at most 40 carbon atoms, preferably 35 or less. Representative examples of the dibasic unsaturated carboxylic acids include maleic acid, itaconic acid, nadecic acid and fumaric acid. In addition, typical examples of derivatives of dibasic unsaturated carboxylic acids include acid anhydrides of the dibasic unsaturated acids;
esters, amide compounds and their metals (metals usually include alkali metals and metals of groups A and B of the periodic table, such as sodium,
Examples include magnesium, calcium, zinc) salts. Suitable examples of these dibasic unsaturated carboxylic acids and derivatives thereof include maleic acid, maleic anhydride, nadecic acid and nadecic anhydride. Furthermore, the number of carbon atoms in the olefin is generally at most 12, and preferably 8 or less. Representative examples of desirable olefins include ethylene, propylene and butene-1;
Ethylene is particularly suitable. The composition ratio of olefin in this multi-component copolymer is 30
~99.85% by weight, particularly preferably 40~98.5% by weight. In addition, the composition ratio of α,β-ethylenically unsaturated carboxylic acid ester is 0.1 to 50% by weight,
Particularly desirable is 1.0 to 50% by weight. Further, the composition ratio of the dibasic unsaturated carboxylic acid or its derivative is 0.05 to 20% by weight as a total amount thereof, and particularly preferably 0.5 to 10% by weight. If the composition ratios of α,β-type unsaturated carboxylic acid ester and dibasic unsaturated carboxylic acid or its derivative in this multi-component copolymer are below the respective lower limits, the adhesiveness of the resulting modified olefin polymer will be poor. Karasushi is also not something to be satisfied with. On the other hand, if the upper limit is exceeded, the softening point of the multi-component copolymer will increase, the fluidity will decrease, and it will not only become difficult to modify (process) the unsaturated carboxylic acid or its derivative as described below. It is also economically unfavorable. The melt flow index (measured under conditions 4 according to JIS K7210, hereinafter referred to as "MFR") of this multi-component copolymer is usually 0.01 to 100 g/10 minutes, preferably 0.05 to 100 g/10 minutes, especially 0.1
~50g/10 minutes is suitable. MFR is 0.01g/10
If a multicomponent copolymer with a molecular weight of less than On the other hand, if it exceeds 100 g/10 minutes, moldability is poor. This multi-component copolymer is produced using the generally well-known radical high-pressure polymerization method, for example, each monomer is polymerized under high pressure (generally 500 to 2500 kg/cm ² ) and at high temperature (generally 120 kg/cm 2 ).
It can be easily produced by a radical polymerization method using a chain transfer agent if necessary at a temperature of ~260°C. (B) Unsaturated carboxylic acid or its derivative Treatment (modification) of the olefin-based multi-component copolymer
Examples of unsaturated carboxylic acids or derivatives thereof used for this purpose include monobasic unsaturated carboxylic acids, dibasic unsaturated carboxylic acids, and metal salts, amides, imides, and the like of these unsaturated carboxylic acids.
Mention may be made of esters and anhydrides. Among these, the monobasic unsaturated carboxylic acid usually has at most 30 carbon atoms, and preferably 25 or less carbon atoms. Representative examples of monobasic unsaturated carboxylic acids include acrylic acid and methacrylic acid. Also,
Typical examples of dibasic unsaturated carboxylic acids and their derivatives include maleic acid, fumaric acid, itaconic acid, and 5-norbornene-2,3-dicarboxylic acid as dibasic unsaturated carboxylic acids, and maleic anhydride as their anhydrides. acid, 5-norbornene-2,
Examples include 3-dicarboxylic anhydride and tetrahydrophthalic anhydride, monoethyl or diethyl maleate and glycidyl methacrylate as esters thereof, and maleimide as imide. Among these unsaturated carboxylic acids or derivatives thereof, anhydrides of dibasic unsaturated carboxylic acids are preferred. (C) Radical initiator Furthermore, the decomposition temperature of the radical initiator used in the present invention with a half-life of 1 minute is usually 100°C or higher, preferably 105°C or higher, and particularly preferably 120°C or higher. be. Representative examples of suitable radical initiators include diwalnut peroxide, benzoyl peroxide, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di(tert-butyl-peroxy). Hexane, 2,5-dimethyl-2,5-di(tertiary-butylperoxy)hexane-3, lauroyl peroxide,
Examples include organic peroxides such as tertiary-butyl peroxybenzoate. (D) Usage ratio The usage ratio of the unsaturated carboxylic acid and its derivative and the radical initiator to 100 parts by weight of the olefinic multi-component copolymer is usually as follows. For unsaturated carboxylic acids and their derivatives, their total amount is 0.01 to 5.0 parts by weight, and 0.05 to 5.0 parts by weight.
The amount is preferably 3.0 parts by weight, particularly preferably 0.1 to 2.0 parts by weight. If the total amount of unsaturated carboxylic acids and their derivatives used is less than 0.01 part by weight, the adhesiveness of the resulting modified olefin polymer will be insufficient. On the other hand, if it exceeds 5.0 parts by weight, there is a risk that decomposition or crosslinking reactions will occur simultaneously during production of the modified olefin polymer. In addition, for radical initiators, the amount is 0.001 to 1.0 parts by weight, preferably 0.01 to 1.0 parts by weight, and especially
It is 0.01 to 0.5 parts by weight. When the proportion of the radical initiator used is less than 0.001 parts by weight, the modification effect is not sufficiently exerted, and not only does it take a long time to complete the modification, but also unreacted substances are mixed. On the other hand, if it exceeds 1.0 part by weight, excessive decomposition or crosslinking reaction may occur, which is undesirable. (E) Production of modified olefin polymer The modified olefin polymer of the present invention can be produced by known means for producing this type of modified olefin polymer. A typical production method involves preparing the olefinic multi-component copolymer, unsaturated carboxylic acid or its derivative, and the like in a solvent such as an aromatic hydrocarbon compound such as xylene or toluene, or an aliphatic hydrocarbon compound such as hexane or heptane. A method of manufacturing by heating and mixing a radical initiator, and a method of manufacturing by mixing these olefin-based multi-component copolymers, unsaturated carboxylic acids or derivatives thereof, and a radical initiator in advance under conditions that essentially do not crosslink, and then mixing the resulting mixture with a screw method. Production methods include melt-mixing using kneaders commonly used in the field of synthetic resins, such as extruders, Banbury mixers, and kneaders, but the latter method is preferred in terms of operation and economy. Then, he was hired. In the latter case, the temperature conditions for modification are appropriately selected taking into consideration the deterioration of the olefin-based multi-component copolymer, the decomposition of the unsaturated carboxylic acid or its derivative, the decomposition temperature of the organic peroxide, etc. is 100 to 350°C, preferably 150 to 350°C, particularly preferably 150 to 300°C. (F) Modified olefin polymer and its use, etc. The modified olefin polymer obtained as described above exhibits excellent adhesion to various substances (substrates) as shown in the examples below. . That is, low density to high density polyethylene,
linear low-density polyethylene, olefin-vinyl ester copolymers (e.g., ethylene-vinyl acetate copolymers), olefin-unsaturated carboxylic acids (e.g., ethylene-acrylic acid copolymers); -Propylene copolymer rubber (EPR, EPDM), low crystallinity ethylene-
A modified olefin polymer obtained by modifying a composition containing a small amount of an elastomer such as butene-1 copolymer or polyisobutylene with an unsaturated carboxylic acid or a derivative thereof, or the modified polymer and unmodified polymer. Compared to other olefin polymers, it exhibits unprecedentedly high adhesion. The modified olefin polymer of the present invention may be used as it is, or the above-mentioned polymers and elastomers may be added to the modified olefin polymer as long as the properties of the modified olefin polymer are not essentially impaired. In addition, additives such as heat, light and oxygen stabilizers, lubricants, plasticizers, fillers, antistatic agents, and colorants such as pigments, which are widely used in the field of olefin resins, can be added to the modified olefin resins of the present invention. It may be added within a range that does not essentially impair the properties of the polymer. Of course, these additives may be blended (added) when the olefin-based multi-component copolymer is modified with an unsaturated carboxylic acid or a derivative thereof. As described above, the modified olefin polymer obtained by the present invention has good adhesion to various substrates. Typical examples of this base material include unmodified polyethylene, olefin-vinyl ester copolymer, olefin-unsaturated carboxylic acid copolymer, saponified ethylene-vinyl acetate copolymer,
Synthetic resins such as amide polymers, saturated polyester polymers, polyvinyl chloride polymers, polyvinylidene chloride polymers, polycarbonate polymers, polyacrylonitrile polymers, polystyrene polymers, and fluorine polymers , various metals, wood, glass, various woven fabrics, paper, and unsaturated polyester resins containing glass fibers. The modified olefin polymer of the present invention and at least one of these base materials are laminated and formed into a film, sheet, blow bottle, tube, etc., and can be used as food packaging materials, industrial materials, drugs, etc. It can be used very effectively in fields such as packaging materials for cosmetics. In addition, organic and inorganic fillers such as glass fibers, beads, calcium carbonate, talc, wood flour, and carbon black, metal fillers such as powders and flakes of metals (for example, iron, copper, and aluminum), and the various thermoplastic resins mentioned above. It can also be effectively used as a modifier or compatibilizer to impart compatibility with EXAMPLES AND COMPARATIVE EXAMPLES The present invention will now be explained in more detail with reference to Examples. In addition, in the adhesive evaluation column, the peel strength is determined by peeling a layer such as a modified olefin polymer (hereinafter referred to as "layer A") and another base material (hereinafter referred to as "layer B") at a peeling speed of 100 mm/ The film was peeled using a Tensilon type tensile tester under conditions of 180 degrees and a peel angle, and its resistance value (g/15 mm) was determined. Examples 1 and 2, Comparative Examples 1 to 5 Ethylene-methyl methacrylate-maleic anhydride terpolymer (MFR) in which the copolymerization ratio of methyl methacrylate is 8.0% by weight and the copolymerization ratio of maleic anhydride is 2.0% by weight. 2.0g/10 minutes,
Example 1), hereinafter referred to as "EMMAH", and an ethylene-ethyl acrylate-maleic anhydride ternary copolymer in which the copolymerization ratio of ethyl acrylate is 15.0% by weight and the copolymerization ratio of maleic anhydride is 1.5% by weight. Combination (MFR 15g/10 minutes, hereinafter referred to as "EEAH")
Example 2) For each 100 parts by weight,
Using 0.012 parts by weight of di-tertiary-butyl peroxide as a radical initiator, dry blending was performed in advance for 5 minutes using a Henschel mixer. 0.5 parts by weight of maleic anhydride was added to each of the resulting mixtures, and dry bren was further performed for 5 minutes using the Henschel mixer to produce mixtures. Each mixture thus obtained was processed using a non-vent type extruder (diameter 40 mm).
Mixing and extrusion was performed while melting at a temperature of 220°C to produce modified olefin polymers [hereinafter referred to as "modified product (A)" and "modified product (B)", respectively]. Instead of EMMAH used in Example 1,
High-density polyethylene with a density of 0.950 g/cm ³ (MFR 1.2 g/10 minutes, hereinafter referred to as "HDPE", Comparative Example 1), low-density polyethylene with a density of 0.920 g/cm ³ (MFR 4.0 g/10 minutes, Hereinafter referred to as "LDPE",
Comparative Example 2), a linear low-density ethylene-butene-1 copolymer with a density of 0.92 g/cm ³ (MFR2.0 g/cm 3 ),
10 minutes, hereinafter referred to as "L-LDPE", Comparative Example 3),
Ethylene-vinyl acetate copolymer (MFR 10 g/10 min, hereinafter referred to as "EVA", Comparative Example 4) in which the copolymerization ratio of vinyl acetate is 10% by weight and the copolymerization ratio of methyl methacrylate is 8.2% by weight. Ethylene-methyl methacrylate copolymer (MFR3.5
g/10 minutes, hereinafter referred to as "EMMA", Comparative Example 5)
Dry blending was carried out in the same manner as in Example 1, except that each of the following was used. Each of the obtained mixtures was melt-mixed and extruded under the same conditions as in Example 1 to obtain each modified olefin polymer [hereinafter referred to as "modified product"].
(C)”, “Modified product (D)”, “Modified product (E)”, “Modified product (F)”
and "modified product (G)"] were produced. Modified product obtained as above as layer A (A)
or modified product (G) and different materials whose types are shown in Table 1 as the B layer, coextrusion molding of two types and two layers is performed to form various multilayer films (the thickness of the A layer is 60 mm). micron, B layer thickness 40 micron). The length in the M direction of each film obtained is
A test piece with a width of 100 mm and a width of 15 mm was cut, and the peel strength between layer A and layer B was measured. The results obtained are shown in Table 1. In the section of "Different materials" in Table 1, "EVOH" refers to a saponified copolymer of ethylene and vinyl acetate (manufactured by Kuraray Co., Ltd., trade name EVAL F), and "PA" refers to polyamide resin (Toray Co., Ltd., trade name EVAL F). Made by
Product name: Nylon CM1021XF), "PVC" is vinyl chloride resin (manufactured by Kureha Chemical Industry Co., Ltd., degree of polymerization: approx.
1000, containing 30% by weight of dioctyl phthalate as a plasticizer), "PET" is polyethylene terephthalate (manufactured by Eastman Chemical Co., USA, trade name)
PET-G), "PVDC" is vinylidene chloride resin (manufactured by Dow Chemical Co., Ltd., pellet PVDF), "PC" is polycarbonate resin (manufactured by Teijin Kasei Co., Ltd., product name
Panlite L), "PS" is polystyrene (manufactured by Nippon Polystyrene Co., Ltd., product name S-Bright 8M),
"PAN" is acrylonitrile resin (manufactured by Mitsui Toatsu Chemical Co., Ltd., trade name Barex 210) and "PVDF"
(manufactured by Atosimy, France, product name: Fuoraclone)
6000HD) respectively.

[Table] Using a screw extruder (diameter 40 mm) equipped with a T-die, the modified product (A) and the modified product (C) and modified product (D) were used for comparison at a temperature of 180°C. A 500 micron film was created. The obtained film and the substrate whose material and thickness are shown in Table 2 (preheated to 150℃) were used at a temperature of 200℃ for 1 minute under a pressure of 50Kg/cm ² (experiment number
In No. 19, a laminate was produced by bonding (pressure applied with a load of 200 g/cm ² ) and cooling to room temperature. A test piece with a width of 15 mm and a length of 150 mm was prepared from each of the obtained laminates, and the peel strength was measured. The results obtained are shown in Table 2.

【table】

[Table] Effects of the Invention The modified olefin polymer obtained by the present invention is a modified polymer obtained by modifying an ethylene polymer or a copolymer containing ethylene as a main component with a vinyl monomer. In comparison, the adhesive strength with various base materials is extremely excellent. Therefore, it is promising as a packaging material for parts of automobiles, electrical equipment, electronic equipment, etc., various industrial parts, building materials, and foods, medicines, cosmetics, etc.

Claims (1)

[Claims] 1 0.1 to 50% by weight of at least one α,β-ethylenically unsaturated carboxylic acid ester selected from the group consisting of acrylic acid alkyl ester and methacrylic acid alkyl ester, and 0.05 to 20% by weight of dibasic unsaturated carboxylic acid or its derivative 1. A method for producing a modified olefin-based polymer, which comprises treating an olefin-based multicomponent copolymer containing % by weight as monomer units with an unsaturated carboxylic acid or a derivative thereof in the presence of a radical initiator.