JPH0623361B2 - Adhesive made of chlorinated modified polyolefin - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adhesive, and more specifically, to the adhesiveness between a polyolefin such as polypropylene or poly-1-butene and other adherends. The present invention relates to a novel chlorinated modified polyolefin adhesive.

[Prior Art] Polyolefins such as polypropylene are adhered to other materials, for example, various foams, woven fabrics, non-woven fabrics, etc., or a metal layer is formed by vacuum vapor deposition, sputtering, etc. to make a composite, and the field of use thereof. There is a great demand to expand the. However, since polyolefin is non-polar and has poor adhesiveness and adhesiveness, it is not easy to form a composite. Therefore, various methods have been proposed. For example, a method of modifying the polyolefin itself, a method of treating the polyolefin surface such as a corona treatment, a method of using a primer, a method of using an adhesive, etc. are properly used according to the purpose. Of these methods, the method using a solvent-coated primer or adhesive is simple and has a wide range of applications, and thus has attracted particular attention.

As one of those used for such a purpose, there is known one obtained by further chlorinating polypropylene graft-modified with a monomer having a certain carboxyl group. For example, in Japanese Examined Patent Publication No. 50-10916, a polyα-olefin having a melt viscosity at 190 ° C. of about 100 to 5000 cp and a logarithmic viscosity of about 0.1 to 0.5 is reacted with an unsaturated carboxylic acid and then chlorinated to be used as an undercoating agent. It has been shown to be possible. 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, according to the study by the present inventors, ordinary polypropylene or the like is heated. When low molecular weight polypropylene or the like obtained by decomposition is used as a raw material, gelation is likely to occur at the time of grafting and remains as an insoluble component which is not preferable as an adhesive or a paint in the final product after chlorination, which is not preferable. When a low molecular weight polypropylene or the like having a small number of double bonds obtained by direct polymerization is used as a raw material, the logarithmic viscosity is lowered by molecular cleavage during grafting, and is reduced to about 0.3 or less. When a product obtained by chlorinating a graft polymer having such a logarithmic viscosity range is used as an adhesive or an adhesive brimer, good adhesiveness is obtained because the cohesive force of the adhesive (or primer) decreases. I can't. Also, under high temperature (eg 80
When it is used at temperatures of up to 100 ° C, the heat resistance is inferior, so that it does not show satisfactory performance.

Japanese Patent Application Laid-Open No. 51-42794 also proposes a method of subjecting a polyolefin to the same graft modification and then chlorinating it. However, in this publication, a concretely described grafted polypropylene has a molecular weight of Is 4000 (the intrinsic viscosity measured in a delican at 135 ° C. is about 0.15 dl / g), and has the above-mentioned drawbacks when used for an adhesive or an adhesive primer as in the above publication. There is.

Further, JP-A-55-149304 discloses an adhesive resin obtained by chlorinating a modified polypropylene containing a carboxyl group. However, the modified polypropylene specifically disclosed in this publication has a Melton index of 9
Or 22 (with an intrinsic viscosity of approximately 2.3 dl / g or 1.7
dl / g)) only. A product obtained by chlorinating a modified polypropylene having such a large molecular weight has poor solubility in a solvent, and therefore, when used as an undercoating agent in the case of vacuum deposition, for example, the smoothness is poor and the appearance of the deposited product is particularly glossy. Is not satisfactory because it shows the drawback of decreasing.

[Problems to be Solved by the Invention] The present inventors have improved the proposed techniques as described above, and have made it possible to use polyolefins, particularly polypropylene and poly-1-butene, and adherends such as polyolefin, polyvinyl chloride, polyurethane, Various foams such as nylon, sheets, films and various papers, metal foils such as aluminum, as an adhesive with an inorganic plate such as calcium silicate, or as a primer when using an adherend as described above, Furthermore, an adhesive having excellent adhesiveness, heat resistance, flexibility, and chemical resistance was investigated as a brimer in vacuum deposition. As a result, it was found that a graft-modified polyolefin having an acid value and a molecular weight obtained by graft-modifying a specific polyolefin in a specific range chlorinated to have a predetermined chlorine content satisfies such requirements. The present invention has been reached.

[Means for Solving Problems] According to the present invention, the intrinsic viscosity [η] (measured in decalin at 135 ° C., the same applies hereinafter) as the main constituent unit of an α-olefin having 3 to 4 carbon atoms is 1 dl. / G or more of a polyolefin graft-modified with an unsaturated dicarboxylic acid or an anhydride thereof to obtain an acid value of 5 to 100 and an intrinsic viscosity [η] (measured in decalin at 135 ° C) of 0.4 to 1 dl / g. There is provided an adhesive comprising a chlorinated modified polyolefin having a chlorine content of 10 to 40% by weight obtained by further chlorinating the modified polyolefin.

The polyolefin, which is the base of the modified polyolefin used as the adhesive of the present invention, has a main constituent unit of 3 carbon atoms.
4 to 4, that is, a polymer of propylene and / or 1-butene, which may be a homopolymer or a copolymer. 40% by mole in the copolymer
The following may be contained, preferably 30 mol% or less, of other α-olefin units. Examples of such other α-olefins include ethylene, 1-pentene, 1-hexane, 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. X as such a polyolefin
It is preferable that the crystallinity by line diffraction is 5% or more.

The chlorinated modified polyolefin used as the adhesive of the present invention has an acid value of 5 to 100, preferably 10 to 80, and an intrinsic viscosity obtained by graft-modifying the above-mentioned polyolefin with an unsaturated dicarboxylic acid or an anhydride thereof. η]
Is 0.4 to 1 dl / g, preferably 0.5 to 1 dl / g
belongs to. The chlorinated modified polyolefin produced using an acid value of less than 5 is not preferable because it has a drawback of poor adhesion to polar materials such as metal, polyurethane and nylon, and has an acid value of more than 100. However, when a gel component is formed by cross-linking, the solubility of the chlorinated modified polyolefin in a solvent becomes poor, or the modified product obtained by grafting an unsaturated dicarboxylic acid or its acid anhydride has an intrinsic viscosity [η]. Is significantly reduced, which is not preferable. On the other hand, a chlorinated modified polyolefin produced by using a graft-modified polyolefin having an intrinsic viscosity of less than 0.4 dl / g is inferior in adhesiveness, heat resistance and chemical resistance due to its low cohesive force, which is preferable. Furthermore, a graft-modified polyolefin having an intrinsic viscosity of more than 1 dl / g is unsatisfactory in terms of solubility in a solvent and poor compatibility in blending with other resins.

The graft component of the graft-modified polyolefin is unsaturated dicarboxylic acid or its anhydride. Specifically, maleic acid, fumaric acid, itaconic acid, citraconic acid, allyl succinic acid, mesaconic acid, glutaconic acid, nadic acid, methyl nadic acid, tetrahydrophthalic acid, methyl tetrahydrophthalic acid, or their anhydrides. May be two or more. Further, these graft-modified polyolefins may be co-grafted with a small amount of other vinyl monomers such as styrene and maleic acid monoester, for example, unsaturated dicarboxylic acid or its anhydride in an equimolar ratio or less. . Of these graft components, those of maleic acid, maleic anhydride, nadic acid or nadic anhydride are particularly preferred.

The technique for producing such a graft-modified polyolefin 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, the monomer component, and the radical generator are supplied to an extruder and kneaded while the polyolefin is molten is applied. do it.
In order to obtain the graft-modified polyolefin having the above-mentioned properties, as described above, the raw material polyolefin has an intrinsic viscosity of 1 to 10 dl / g, preferably 1.
It is only necessary to use 5 to 7 dl / g, and to adopt the condition that a modified polyolefin having a predetermined molecular weight and graft amount can be produced without decomposition. For example, an organic peroxide or an organic perester may be used as the radical generator, and the reaction may be performed at a temperature of about 80 to 250 ° C. by a method using a solvent, or at a temperature of about 150 to 350 ° C. by a method using an extruder.

The chlorinated modified polyolefin used as the adhesive of the present invention is obtained by chlorinating the above-mentioned graft modified polyolefin so as to have a chlorine content of 10 to 40% by weight, preferably 15 to 35% by weight. is there.
Those having a chlorine content of 10% by weight or less have poor solubility in a solvent, and those having a chlorine content of more than 40% by weight have poor adhesion to polypropyrin. The intrinsic viscosity of chlorinated modified polyolefin is usually 0.1 to 1 dl / g,
It is preferably in the range of 0.3 to 0.8 dl / g, and the residual crystallinity is preferably 20 to 0%.

Chlorination of the graft-modified polyolefin can be performed in a state of being dissolved in a suitable solvent or in a state of being dispersed. As a solvent that can be used for such a purpose,
Hexane, heptane, octane, decane, dodecane, tetradecane, aliphatic hydrocarbons such as kerosene, methylcyclopentane, cyclohexane, methylcyclohexane,
Alicyclic hydrocarbons such as cyclooctane and cyclododecane, benzene, toluene, xylene, ethylbenzene,
Aromatic hydrocarbons such as cumene, ethyltoluene, trimethylbenzene, cymene and diisopropylbenzene, chlorobenzene, bromobenzene, o-dichlorobenzene, carbon tetrachloride, carbon tetrabromide, chloroform, bromoform, trichloroethane, trichloroethylene, tetrachloroethane, tetrachloroethylene Examples thereof include halogenated carbon hydride and the like. Of these, halogenated hydrocarbons are particularly preferable.

The chlorination reaction is preferably carried out by introducing chlorine gas in the solvent as described above until a predetermined chlorine content is reached. In carrying out the chlorination reaction, ultraviolet rays or visible rays may be irradiated, or a radical generator may be used for the purpose of efficiently proceeding the reaction. The temperature of the chlorination reaction is usually about 50 to 120 ° C., and the reaction time is generally in the range of about 0.5 to 5 hours.

[Advantages of the Invention] The adhesive of the present invention can be used by dissolving or dispersing the chlorinated modified polyolefin in various solvents, or can be used in the form of powder. Solvents that can be used for this purpose include the aliphatic compounds mentioned above,
In addition to alicyclic and aromatic hydrocarbons and halogenated hydrocarbons, ketones such as acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, diisobutyl ketone and isophorone, methyl acetate, ethyl acetate,
Examples thereof include esters such as isopropyl acetate and isobutyl acetate.

The adhesive of the present invention is useful as an adhesive or a primer for polyolefins, particularly polypropylene and poly-1-butene. For example, for polyolefin molded products,
As an adhesive for directly adhering films, sheets, foams, woven fabrics, non-woven fabrics, etc. of polyolefins or polyvinyl chloride, polyvinylidene chloride, polyamide, polyester, etc., or rubber-based, urethane-based, epoxy resin-based, acrylic-based It is useful as a primer for bonding via each adhesive such as silicone-based adhesive, and is excellent not only in adhesiveness but also in heat resistance and chemical resistance. When it is used as a primer, use a melt type one, and after applying it to a polyolefin molded product, while the application surface is still in a wet state, adhere the adherend or apply another adhesive, etc. The method can be adopted. Alternatively, it is also useful as a primer when metal-coating a polyolefin molded product by vacuum vapor deposition, sputtering, etc. because of its excellent adhesiveness, smoothness, and solvent resistance. For example, after applying a chlorinated modified polyolefin which is the adhesive of the present invention to a polyolefin molded article, vacuum deposition or the like can be performed with or without an undercoat. The applicant has already proposed in Japanese Patent Publication No. 63-36624 the use of the paint as an undercoating agent.

Others The adhesive of the present invention has excellent compatibility with rubbers such as urethane resins, epoxy resins, acrylic resins, and chloroprene resins, and has a weight ratio of, for example, 10 resin components.
They can be mixed and used in the ratio of / 90 to 90/10. To obtain a laminate having excellent workability when used as such a one-pack type adhesive, and more excellent adhesiveness and heat resistance than the case where the adhesive is used alone depending on the type of adherend. You can

Incidentally, the chlorinated modified polyolefin which is the adhesive of the present invention, within the range which does not impair the object of the invention, a heat stabilizer, a weather stabilizer, a hydrochloric acid absorbent, calcium carbonate, calcium sulfate, talc, glass flakes, barium sulfate, clay,
Fillers such as kaolin, finely divided silica, mica, calcium silicate, aluminum hydroxide, magnesium hydroxide, aluminum oxide and magnesium oxide may be blended and used.

[Example] Reference Example 1 (1) Polyolefin Modified with Maleic Anhydride The intrinsic viscosity [η] measured at 135 ° C in decalin was 2.0 dl /
Using 25 g of polypropylene as a solution of 25% by weight, 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 a polymer, which was separated by filtration, repeatedly washed with acetone, and then vacuum dried to obtain a maleic anhydride-grafted polypropylene having 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, light was blocked at the same temperature, and chlorine gas was introduced into this to reduce the chlorine content. Chlorination was carried out to 25% by weight. The reaction time was about 2 hours.

A large excess of methanol was added to the reaction mixture to precipitate a polymer, which was separated by filtration, repeatedly washed with methanol, and then dried in a nitrogen stream to obtain a chlorinated product of maleic anhydride-grafted polypropylene.

(3) Preparation of primer and adhesive Dissolve the chlorinated product thus obtained in toluene to give a concentration of 1
A 0 wt% solution was prepared.

Reference Examples 2 to 6 and Comparative Reference Examples 1 to 5 Using the polyolefins shown in Table 1, maleic anhydride modification and chlorination were performed in the same manner as in Example 1 to synthesize the graft-modified polymers and chlorinated products shown in Table 1. Then, a toluene solution was prepared in the same manner.

The solubility of this toluene solution at room temperature was visually determined.

Next, the following adhesion test was performed using the modified product.

Examples 1 to 6, Comparative Examples 1 to 5 Polypropylene (trade name Mitsui Petrochemical Polypro ^R J34
(0) sheet (25 mm × 130 mm × 3 mm) or polybutene (Mitsui Petrochemical Polybutene ^R M801N) sheet was wiped with toluene, and then a chlorinated toluene solution shown in Table 1 was brushed on it to give various coatings shown in Table 2. The adhered body and a roller were stuck together and left at room temperature for 5 days.

The adhesive strength was measured by an Instron tester at 180 ° peeling at 23 ° C. and a pulling speed of 100 mm / min. The results are shown in Table 2.

Examples 7 to 9 and Comparative Examples 6 to 8 The chlorinated products shown in Reference Example 1 and Comparative Reference Example 1 were applied as a primer to the above-mentioned polypropylene sheet, various adhesives were applied thereon, and a foamed vinyl chloride sheet was applied to the roller. After bonding for 5 days at room temperature, the adhesive strength was measured by the method described above. Moreover, in order to evaluate the adhesiveness under high temperature, the adhesive strength under the temperature condition of 80 ° C. was measured. The results are shown in Table 3.

Examples 10 to 12, Comparative Example 9 The chlorinated modified polypropylene (A) shown in Reference Example 1 and Comparative Reference Example 1 was used as the urethane adhesive (B) (KU-10, Konishi).
An adhesive was prepared by mixing it with the main component of Co., Ltd. and further adding a curing agent. This adhesive was applied to the above-mentioned polypropylene sheet, foamed polyurethane was adhered thereto, left at room temperature for 5 days, and then 180 ° peel strength was measured at room temperature and 80 ° C. The results are shown in Table 4.

Example 13, Comparative Example 10 The chlorinated modified polypropylene shown in Reference Example 3 and Comparative Reference Example 1 was applied to the above-mentioned polypropylene sheet and dried at room temperature, and then a vacuum deposition apparatus (JEF-4B manufactured by JEOL Ltd.) was used. Then, vacuum deposition of aluminum was performed, and the adhesion was evaluated by a cross cut test (JIS K 5400 6.15). The results are shown in Table 5.

Claims (1)

[Claims] 1. An unsaturated dicarboxylic acid or an anhydride thereof, which is a polyolefin having an intrinsic viscosity [η] containing an α-olefin having 3 to 4 carbon atoms as a main constituent unit (measured in decalin at 135 ° C.) of 1 dl / g or more. The acid value obtained by graft-modifying with a substance is 5 to 100, and the intrinsic viscosity [η] is 0.4 to 1 dl.
An adhesive comprising a chlorinated modified polyolefin having a chlorine content of 10 to 40% by weight, which is obtained by further chlorinating / g of modified polyolefin.