JPH0216921B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a chlorinated modified polyolefin, and more specifically to an adhesive, particularly an adhesive between a polyolefin such as polypropylene or poly-1-butene and another adherend. The present invention relates to a method for producing a novel chlorinated modified polyolefin suitable as a polyolefin. [Prior art] Polyolefin such as polypropylene is composited by bonding other materials such as various foams, woven fabrics, non-woven fabrics, etc., or by forming a metal layer by vacuum deposition or sputtering. There is a great demand to expand the field of use. However, polyolefins are non-polar and have poor adhesion and adhesion properties, so it is not easy to combine them into composites.
Various methods have been proposed for this purpose. For example, methods of modifying the polyolefin itself, methods of treating the surface of the polyolefin such as corona treatment, methods of using a primer, methods of using an adhesive, etc. are used depending on the purpose. Among these methods, methods using solvent-coated primers or adhesives are attracting particular attention because they are simple and have a wide range of applications. As one of the materials used for this purpose, polypropylene graft-modified with a certain kind of carboxyl group-containing monomer and further chlorinated is known. For example, special public service in the 1970s.
In Publication No. 10916, the melt viscosity at 190°C is approximately 100
It has been shown that a poly-α-olefin having a logarithmic viscosity of about 0.1 to 0.5 and an unsaturated carboxylic acid reacted with each other and then chlorinated can be used as a non-coating agent. According to the studies of the present inventors, when polypropylene or poly-1-butene having the above-mentioned logarithmic viscosity is grafted with an unsaturated carboxylic acid according to the method disclosed in this publication, ordinary polypropylene, etc. If low-molecular-weight polypropylene obtained by thermally decomposing polypropylene is used as a raw material, it is undesirable because it tends to gel during grafting and remains in the final product after chlorination as an insoluble component, which is undesirable as an adhesive or paint. . Furthermore, if a low molecular weight polypropylene with few double bonds obtained by direct polymerization is used as a raw material, its logarithmic viscosity decreases due to molecular scission during grafting, and the logarithmic viscosity decreases to approximately 0.3
decreases below. When a chlorinated graft polymer with such a logarithmic viscosity range is used as an adhesive or an adhesive primer, good adhesion cannot be obtained because the cohesive force of the adhesive (or primer) is reduced. I can't. Also under high temperature (e.g. 80
-100℃), it does not exhibit sufficiently satisfactory performance due to poor heat resistance. JP-A-51-42794 also proposes a method in which polyolefin is subjected to similar graft modification and then chlorinated; however, what is specifically described as grafted polypropylene in this publication also has a molecular weight 4000 (intrinsic viscosity measured in decalin at 135°C is approximately 0.15 dl/g), and it has the same drawbacks as those in the above-mentioned publication when used in adhesives or adhesive primers. There is. Further, JP-A-55-149304 also discloses an adhesive resin obtained by chlorinating modified polypropylene containing a carboxyl group. However, the modified polypropylene specifically disclosed in this publication is only one with a melt index of 9 or 22 (intrinsic viscosity of approximately 2.3 dl/g or 1.7 dl/g). Polypropylene obtained by chlorinating such a modified polypropylene with a large molecular weight has poor solubility in solvents, so when used as an undercoat for vacuum deposition, for example, it has poor smoothness and reduces the appearance, especially gloss, of the deposited product. It cannot be said to be satisfactory because it shows the drawback of deterioration. [Problems to be solved by the invention] The present inventors have improved the various proposed techniques as described above,
A polyolefin, especially polypropylene or poly-1-butene, and an adherend, such as a polyolefin,
It can be used as an adhesive for various foams, sheets, films, and papers such as polyvinyl chloride, polyurethane, and nylon, metal foils such as aluminum, and inorganic plates such as calcium silicate, or as an adhesive for adherends such as those mentioned above. As a primer when used, and also as a primer in vacuum evaporation etc., it has excellent adhesion, durability,
We investigated adhesive elements that exhibit excellent properties such as flexibility and chemical resistance. As a result, it was found that graft-modified polyolefin obtained by graft-modifying a specific polyolefin and having an acid value and molecular weight within a specific range was chlorinated to a predetermined chlorine content and satisfied these requirements. This led to the present invention. [Means for Solving the Problems] According to the present invention, the intrinsic viscosity [η] (135°C
A polyolefin with an acid value of 5 to 100 and an intrinsic viscosity [η] of (at 135°C The chlorine content obtained by further chlorinating a modified polyolefin (measured in decalin) of 0.4 to 1 dl/g
A method for producing a chlorinated modified polyolefin is provided, characterized in that the chlorinated modified polyolefin is 40% by weight. The polyolefin that is the base of the modified polyolefin obtained by the present invention has a main structural unit having 3 to 4 carbon atoms, that is, a polymer of propylene and/or 1-butene, and these are homopolymers. may also be a copolymer. In the copolymer, 40 mol% or less, preferably 30
It may contain up to mol % of other α-olefin units. Such other α-olefins include ethylene, 1-pentene, 1-hexene,
Examples include 1-octene, 1-decene, 4-methyl-1-pentene, and the like. As such a polyolefin, one having an intrinsic viscosity [η] of 1 dl/g or more, for example 10 dl/g or less, preferably 1.5 to 7 dl/g, is used. Such polyolefins preferably have a crystallinity of 5% or more as measured by X-ray diffraction. The chlorinated modified polyolefin obtained by the present invention is obtained by graft-modifying the aforementioned polyolefin with an unsaturated dicarboxylic acid or its anhydride, has an acid value of 5 to 100, preferably 10 to 80, and has an intrinsic viscosity [η] is 0.4 to 1 dl/g, preferably 0.5
or 1 dl/g. The chlorinated modified polyolefin produced using a material having an acid value of less than 5 is a polar material such as metal, polyurethane,
It is undesirable because it has poor adhesion to nylon, etc., and if a material with an acid value exceeding 100 is used, a gel component is formed due to crosslinking, resulting in poor solubility of the chlorinated modified polyolefin in solvents and unsaturated This is not preferred because the intrinsic viscosity [η] of the modified product obtained by grafting the dicarboxylic acid or its acid anhydride is significantly reduced.
On the other hand, the intrinsic viscosity of graft-modified polyolefin is
Chlorinated modified polyolefin produced using less than 0.4 dl/g is undesirable because it has low cohesive force and is inferior in terms of adhesiveness, heat resistance, and chemical resistance, and furthermore, the intrinsic viscosity is 1 dl/g. Graft-modified polyolefins exceeding the above range are unsatisfactory in terms of solubility in solvents and poor compatibility in blending with other resins. The graft component of the graft-modified polyolefin is an unsaturated dicarboxylic acid or its anhydride.
Specifically, these are maleic acid, fumaric acid, itaconic acid, citraconic acid, allylsuccinic acid, mesaconic acid, glutaconic acid, nadicic acid, methylnadic acid, tetrahydrophthalic acid, methyltetrahydrophthalic acid, or anhydrides thereof. There may be two or more types. In addition, other vinyl monomers such as styrene, maleic acid monoester, etc. may be co-grafted to these graft-modified polyolefins in a small amount, for example, in an equimolar or less proportion with an unsaturated dicarboxylic acid or its anhydride. . Among these graft components, maleic acid, maleic anhydride, nadic acid or nadic acid anhydride are particularly preferred. The technology for producing such graft-modified polyolefins is basically already known. For example, a method in which polyolefin is dissolved in an organic solvent, a monomer component and a radical generator are added, and the mixture is heated and stirred, a method in which the polyolefin, monomer component, and radical generator are fed to an extruder, and kneaded while the polyolefin is melted is applied. do it. In order to obtain the graft-modified polyolefin with the above-mentioned properties, as mentioned above, a polyolefin having an intrinsic viscosity of 1 to 10 dl/g, preferably 1.5 to 7 dl/g is used as a raw material polyolefin, and the polyolefin is heated to a predetermined value without decomposition. It is sufficient to adopt conditions that allow production of a modified polyolefin having a molecular weight and a graft amount of .
For example, an organic peroxide or an organic perester may be used as the radical generator, and the reaction may be carried out at a temperature of about 80 to 250°C in a method using a solvent, and at a temperature of about 150 to 350°C in a method using an extruder. The chlorinated modified polyolefin obtained by the present invention has a chlorine content of 10 to 40% by weight, preferably
It is chlorinated to a proportion of 15 to 35% by weight. Those with a chlorine content of 10% by weight or less have poor solubility in solvents, and those with a chlorine content of more than 40% by weight have poor adhesion to polypropylene. The intrinsic viscosity of the chlorinated modified polyolefin is usually in the range of 0.1 to 1 dl/g, preferably 0.3 to 0.8 dl/g, and the residual crystallinity is preferably 20 to 0%. The graft-modified polyolefin can be chlorinated in a state in which it is dissolved in a suitable solvent or in a state in which it is dispersed. Solvents that can be used for this purpose include hexane, heptane, octane, decane, dodecane, tetradecane, aliphatic hydrocarbons such as kerosene, and fats such as methylcyclopentane, cyclohexane, methylcyclohexane, cyclooctane, and cyclododecane. Cyclic hydrocarbons, aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene, ethyltoluene, trimethylbenzene, cymene, diisopropylbenzene, chlorobenzene, bromobenzene, o-dichlorobenzene, carbon tetrachloride, carbon tetrabromide , chloroform, bromoform, trichloroethane, trichloroethylene, tetrachloroethane, and halogenated hydrocarbons such as tetrachloroethylene. Among these, halogenated hydrocarbons are particularly preferred. The chlorination reaction is preferably carried out in a solvent as described above by introducing chlorine gas until a predetermined chlorine content is reached. When carrying out the chlorination reaction, irradiation with ultraviolet rays or visible light, or the use of a radical generator can be used for the purpose of efficiently advancing the reaction. The temperature of the chlorination reaction is usually between 50 and
The temperature is 120°C, and the reaction time is generally in the range of about 0.5 to 5 hours. [Applications and effects of the present invention] The chlorinated modified polyolefin obtained by the present invention can be used by being dissolved or dispersed in various solvents, or can be used in the form of powder. Solvents that can be used for this purpose include acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and diisobutyl ketone, in addition to the aliphatic, alicyclic, and aromatic hydrocarbons and halogenated hydrocarbons mentioned above. , ketones such as isophorone, and esters such as methyl acetate, ethyl acetate, isopropyl acetate, and isobutyl acetate. The chlorinated modified polyolefin obtained by the present invention is useful as an adhesive for polyolefins, particularly for polypropylene and poly-1-butene. For example, polyolefin molded products, polyolefin, polyvinyl chloride, polyvinylidene chloride, polyamide, polyester, etc. films,
As an adhesive for directly bonding sheets, foams, woven fabrics, non-woven fabrics, etc., or as a primer for bonding through rubber-based, urethane-based, epoxy resin-based, acrylic-based, silicone-based, etc. adhesives. It is useful and has excellent not only adhesive properties but also heat resistance and chemical resistance. For such applications, a method such as applying a melt-type adhesive to a polyolefin molded product and then bonding it to an adherend or applying another adhesive while the coated surface is still wet. can be adopted. Or vacuum evaporation on polyolefin molded products.
It is also useful as a primer for metal coating by sputtering, etc., as it has excellent adhesiveness, smoothness, and solvent resistance. For example, after applying the chlorinated modified polyolefin obtained by the present invention to a polyolefin molded article, an undercoat is applied,
Alternatively, vacuum evaporation or the like can be performed without applying it. Regarding its use as a primer for paint,
The present applicant has already proposed this in Japanese Patent Publication No. 63-36624. In addition, the chlorinated modified polyolefin obtained by the present invention has excellent compatibility with rubbers such as urethane resins, epoxy resins, acrylic resins, and chloroprene rubbers, for example, at a weight ratio of 10/90 in terms of resin components. They can be used by mixing at a ratio of 90/10. When used as a one-component adhesive like this, it not only has excellent workability, but depending on the type of adherend, it can also produce laminates with superior adhesion and heat resistance than when using the above adhesive alone. Obtainable. Furthermore, the chlorinated modified polyolefin obtained by the present invention can also be used as a coating material in addition to the above-mentioned use as an adhesive. In addition, in the above applications, chlorinated modified polyolefins are added with heat-resistant stabilizers, weather-resistant stabilizers, hydrochloric acid absorbers, calcium carbonate, calcium sulfate, talc, glass flakes, barium sulfate, clay, kaolin, finely powdered silica, mica, calcium silicate, water. Fillers such as aluminum oxide, magnesium hydroxide, aluminum oxide, and magnesium oxide may be mixed and used. [Examples] The present invention will be described below based on Examples. Example 1 (1) Maleic anhydride modification of polyolefin The intrinsic viscosity [η] measured at 135°C in decalin was
Using 2.0 dl/g of polypropylene as a 25 wt% toluene solution, a graft reaction of maleic anhydride was carried out at 125° C. for 6 hours using dicumyl peroxide as a radical generator. A large excess of acetone was added to the reaction mixture to precipitate the polymer, which was filtered off, washed repeatedly with acetone, and then vacuum dried to obtain maleic anhydride grafted polypropylene with an acid value of 35. (2) Chlorination of modified polyolefin The maleic anhydride grafted polypropylene obtained by the above method was completely dissolved in a chlorobenzene solvent at 110°C, and at the same temperature, light was blocked and chlorine gas was introduced into it to reduce the chlorine content to 25. Chlorination was carried out until % by weight. The reaction time was approximately 2 hours. A large excess of methanol was added to the reaction mixture to precipitate the polymer, which was filtered, washed repeatedly with methanol, and then dried in a nitrogen stream to obtain a chlorinated maleic anhydride grafted polypropylene. (3) Preparation of primer and adhesive The chlorinated product thus obtained was dissolved in toluene to prepare a solution with a concentration of 10 wt%. Examples 2 to 6, Comparative Examples 1 to 5 Using the polyolefins listed in Table 1, Example 1
Maleic anhydride modification and chlorination were performed in the same manner as above to synthesize the graft modified polymers and chlorinated products listed in Table 1, and toluene solutions were similarly prepared. The solubility of this toluene solution at room temperature was visually determined.

[Table] Next, the following adhesion test was conducted using the above modified product. Reference Examples 1 to 6, Comparative Reference Examples 1 to 5 Polypropylene (trade name Mitsui Petrochemical Polypropylene)
^R J340) sheet (25mm x 130mm x 3mm) or polybutene (Mitsui Petrochemical Polybutene ^R M801N)
After wiping the sheet with toluene, a toluene solution of the chlorinated compound shown in Table 1 was applied by brush, and the sheet was bonded to various adherends shown in Table 2 using a roller and left at room temperature for 5 days. Adhesive strength was measured using an Instron testing machine.
Peeling was performed at 180° at 23°C and a tensile speed of 100 mm/min. The results are shown in Table 2. Reference Examples 7 to 9, Comparative Reference Examples 6 to 8 The chlorinated product shown in Example 1 and Comparative Example 1 was applied as a primer to the aforementioned polypropylene sheet, various adhesives were applied thereon, and the foamed PVC sheet was rolled with a roller. After bonding and leaving at room temperature for 5 days, adhesive strength was measured by the method described above. Furthermore, in order to evaluate adhesiveness under high temperature conditions, adhesive strength was measured at a temperature of 80°C. The results are shown in Table 3. Reference Examples 10 to 12, Comparative Reference Example 9 The chlorinated modified polypropylene A shown in Example 1 and Comparative Example 1 was mixed with urethane adhesive B (KU=10,
Konishi Co., Ltd.) was mixed with the main agent, and a curing agent was further added to prepare an adhesive. This adhesive was applied to the above-mentioned polypropylene sheet, foamed polyurethane was attached, and after leaving it at room temperature for 5 days,
The 180° peel strength at ℃ was measured. The results are shown in Table 4.

[Table] * Composition Reference Example 13 and Comparative Reference Example 10 based on solid content The chlorinated modified polypropylene shown in Example 3 and Comparative Example 1 was coated on the polypropylene sheet described above, dried at room temperature, and then dried using a vacuum evaporation device (JEOL Ltd.). Manufactured by Co., Ltd.
JEF-4B) was used to perform vacuum evaporation of aluminum, and the adhesion was tested using a grid test (JIS K5400 6.15).
Evaluated by. The results are shown in Table 5.

【table】

Claims (1)

[Claims] 1 A polyolefin whose main constituent unit is α-olefin having 3 to 4 carbon atoms and has an intrinsic viscosity [η] (measured in decalin at 135°C) of 1 dl/g or more is graft-modified with an unsaturated dicarboxylic acid or its anhydride. and a modified polyolefin having an acid value of 5 to 100 and an intrinsic viscosity [η] of 0.4 to 1 dl/g, and further,
A method for producing a chlorinated modified polyolefin, which comprises chlorinating this modified polyolefin to obtain a chlorinated modified polyolefin having a chlorine content of 10 to 40% by weight.