JP2517535B2 - Adhesive and method for adhering polypropylene with different polar materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a polypropylene resin molded product without using a primer, a metal such as iron / aluminum, a ceramic, an animal / vegetable fiber, and a polarity other than polyolefin. The present invention relates to an adhesive capable of adhering a product made of a different material to a polyolefin such as a synthetic resin and the like, in particular, an adhesive having excellent heat resistance and a bonding method using the adhesive, in which a large amount of polypropylene is used and It is applied to automobiles, home appliances, audio equipment, etc., which are used in combination with other materials, not taste.

[Conventional technology]

There are various commercially available adhesives that can bond polypropylene resin molded products without using a primer. These are effective for bonding polypropylene resin molded products to each other, but iron, aluminum, etc. It is not effective in adhering foreign materials such as metal, glass, and other polyolefins.

For adhesion between polypropylene and the foreign material,
The surface of the polypropylene molded product to be adhered is treated with a chromic acid / sulfuric acid mixture, and then a commercially available epoxy resin or cyanoacrylate adhesive is used, or polypropylene is modified by adding a filler such as wood powder or talc. After the quality is improved, a method of using a primer or the like is performed.

[Problems to be solved by the invention] The former uses chemicals that are sources of pollution, and the latter uses special brand polypropylene, which is troublesome in terms of management, and the impact strength due to the addition of a filler is fixed. The use of polypropylene cannot be said to be advantageous even if the resin unit price is low, because of the negative effects of materiality, not only the cost of raw materials but also the cost of adhesion due to the addition of the primer coating process.

Therefore, polypropylene is not used when adhering different materials to the plastic, except when polypropylene is required in terms of physical properties.

[Means for solving problems]

In order to solve the above-mentioned problems in adhesion between polypropylene and a heterogeneous material having polarity, the present inventor did not use a primer and did not pretreat, so that unfilled, unmodified polypropylene homopolymer or Considering that there is no choice but to find an adhesive that can bond between copolymers and dissimilar materials, the degree of chlorination of chlorinated polyolefins that are often used as a primer for adhesion or coating of polypropylene, and the adhesion with polypropylene and iron plates A basic study was conducted to show that low-chlorinated polypropylene shows adhesion to polypropylene, but does not adhere to iron plates, and high-chlorinated polyolefin adheres to iron plates, but does not adhere to polypropylene. When mixing and using, adhere to both polypropylene and iron plate. In order to improve the heat resistance of the adhesive and to show higher adhesive strength when used to bond polypropylene and dissimilar materials than the adhesive strength when used to bond polypropylene to each other or to iron plates. When a low chlorinated product of isotactic polypropylene is used for the above, the compatibility is poor and the mixture is separated into two layers when left to stand. Solution, apply solution B to iron pieces,
It has been found that a sufficient adhesive strength can be obtained by stacking the coated surfaces and crimping.

As a result of various studies based on the above findings, the adhesive and the bonding method of the present invention were completed.

That is, the first invention of the present invention contains the following compositions as non-volatile components, One or more mixed solvents selected from the group consisting of aromatic hydrocarbon solvents and chlorinated hydrocarbon solvents,
Alternatively, the gist is an adhesive characterized by comprising two liquids containing a solvent mixed with another solvent containing these solvents as a main component.

And a second aspect of the invention is to apply the liquids A and B to the surfaces to be adhered of the polypropylene molded product and the liquids B to the surfaces of the different materials to be adhered.
The gist is a bonding method characterized in that both coated surfaces are overlapped and pressure-bonded.

[Work]

The above-mentioned adhesive of the first invention exhibits adhesiveness to polypropylene as well as to a material completely different from polypropylene such as metal and glass. Therefore, the polypropylene and the heterogeneous material, which are theoretically difficult, are used as a primer. It can be bonded without using any of the materials, and exhibits a bonding strength better than the bonding strength between the two similar materials.

In addition, the bonding method of the second invention, when bonding, A · B2
Not only the mixing of the liquids can be omitted, but also an adhesive strength equal to or higher than that when the two liquids are mixed and used can be obtained.

 The details will be described below.

Chloroprene rubber, which is one of the non-volatile components in the liquid A, is for imparting tackiness, and in order to maintain cohesive force, it is used that is solid at room temperature. The chlorine content of low-chlorinated polypropylene, which is another non-volatile component, is limited to 35% by weight or less because if it contains more chlorine, it does not exhibit adhesiveness to polypropylene.

As an example of the low chlorinated polypropylene, isotactic polypropylene having a chlorine content of 8 to 30% by weight can be used.

When the chlorine content of the low chlorinated isotactic polypropylene is 8% by weight or less, the solubility in a solvent and the compatibility with other components are significantly reduced, and it is difficult to commercialize it.

There are two types of low chlorinated polypropylene: atactic polypropylene and isotactic polypropylene.
The latter has excellent heat resistance, but has poor solubility and compatibility, and was said to be difficult to apply to adhesives. However, the composition of the present invention enables use and improves heat resistance. .

In addition, in the case of adhesion between polypropylenes, it is possible to adhere only with this A liquid.

The non-volatile component highly chlorinated polyolefin in the liquid B is propylene homopolymer, copolymer of propylene and ethylene or other olefin, ethylene homopolymer, copolymer of ethylene and other α-olefin, and ethylene and vinyl acetate. Highly chlorinated products of various polyolefins and their derivatives such as copolymers with, and particularly preferred are highly chlorinated products of polypropylene, polyethylene and copolymers thereof.

Chlorinated rubber, which is another volatile component, is a highly chlorinated product of natural rubber and diene-based synthetic rubber such as butadiene rubber and styrene-butadiene rubber.

The reason for limiting the chlorine content of the above high chlorinated compound to 60% by weight or more is that it does not exhibit sufficient adhesiveness with different materials below that.

One or more mixed solvents selected from the group consisting of aromatic hydrocarbon solvents and chlorinated hydrocarbon solvents,
Alternatively, the reason for using a mixed solvent of these solvents as a main component with another solvent is as a solvent for dissolving each of the non-volatile components of the above-mentioned liquids A and B, there are other solvents such as ketones and esters. However, a solvent containing these as the main components cannot obtain sufficient adhesive strength.

Aromatic hydrocarbon and chlorinated hydrocarbon solvents are effective because they have the property of swelling or slightly dissolving polypropylene. Among these solvents, preferred are toluene and xylene for aromatic hydrocarbons, and trichloroethylene, tetrachloroethylene, chlorocyclohexane for chlorinated hydrocarbons.

The adhesive of the present invention is a propylene homopolymer, a copolymer of propylene and ethylene or another α-olefin, a modified resin containing these as the main component, and a composite material containing various fillers. It can be applied to adhesion of various polypropylenes.

〔The invention's effect〕

As described above, the adhesive of the present invention enables theoretically difficult adhesion in which polypropylene and completely different materials such as metal and glass are bonded without a primer, and polypropylene and other heterogeneous materials having polarity. Expanded the range of application in combination with materials. Moreover, this adhesive can be prepared with a combination of commercially available materials without using any special material, and since it is divided into the A and B2 liquids, the dissolving and mixing operations for preparing each liquid are easy. Not only is it easy to manufacture, but when bonding polypropylene and dissimilar materials,
The method of applying each liquid to each material and superposing them by pressure without mixing the liquids A and B is easy to work and has high adhesive strength, and the present invention is an economically advantageous adhesive. An agent and an adhesive method are provided. Combined with the above, the present invention is extremely useful industrially.

 Specific examples of the effects of the present invention will be shown by the following examples.

〔Example〕

Liquid A having a composition ratio shown in Table 1 below and liquid B having a composition ratio shown in Table 2 were prepared.

For liquid A, a predetermined amount of chloroprene was weighed out, and toluene was added to the predetermined amount of low-chlorinated polypropylene to remove the non-volatile components of liquid A.
An amount of 20% by weight of toluene was added and dissolved, and the above chloroprene was added to this solution and the container was tightly capped.

Solution B was prepared by dissolving highly chlorinated polypropylene and then chlorinated rubber in a predetermined amount of toluene.

The sample piece for measuring the adhesive strength and the bonding method thereof will be described.

Fig. 1 shows a sample piece for tensile shear strength measurement, which is a polypropylene sample piece 1 (70 × 12.5) prepared by internal drawing from an injection molded piece.
X 2 mm) and a different material (iron) sample piece 2 (70 x 25 x 0.8 mm) obtained by cutting an iron plate, with a 10 mm long adhesion margin, one is a mixed application method, the other is a separate application method. Glued by the method.
In the figure, 3 and 4 are spacers attached to make the thickness of both ends of the sample piece 1.2 equal.

The brands used for producing the polypropylene sample pieces are as follows.

Polypropylene homopolymer Mitsui Toatsu Chemical Co., Ltd. product name Mitsui Noblene JHH-G polypropylene copolymer Same as above Mitsui Noblene BJHH-M Adhesion method After wiping the adhered surface of the sample piece with paper impregnated with isopropyl alcohol, degreasing the surface, Adhesion was performed by the following method.

As a test condition, the tensile shear test has a tensile speed of 50 mm / m.
I went in.

The results of the adhesion experiment are shown in Table 3 below. The numerical value of the adhesive strength is an average value of 3 sample pieces.

[Brief description of drawings]

 FIG. 1 is a side view of a sample piece for measuring tensile shear strength. 1 is a polypropylene sample piece, 2 is an iron sample piece.

Claims (6)

(57) [Claims] 1. A non-volatile component containing the following composition, respectively, and one or more mixed solvents selected from the group consisting of aromatic hydrocarbon solvents and chlorinated hydrocarbon solvents, or An adhesive of polypropylene and a heterogeneous material having polarity, which is characterized by comprising A liquid and B liquid containing a mixed solvent of these solvents as a main component with another solvent. 2. The polypropylene according to claim 1, wherein the low-chlorinated polypropylene contained in the liquid A is a chlorinated product of isotactic polypropylene having a chlorine content of 8 to 30% by weight. Adhesive with different polar materials. 3. The non-volatile component contained in the liquid B has a chlorine content.
An adhesive agent of polypropylene according to claim 1, which comprises 60% by weight or more of highly chlorinated polypropylene and one of chlorinated rubber and chlorinated polyethylene, and a heterogeneous material having polarity. 4. The low chlorinated polypropylene in the liquid A is a chlorinated product of isotactic polypropylene having a chlorine content of 8 to 30% by weight, and the non-volatile component in the liquid B is a chlorine content of 60% by weight or more. 2. An adhesive agent for the polypropylene according to claim 1, which is a mixture of the highly chlorinated polypropylene and the chlorinated rubber or any one of chlorinated polyethylene and a heterogeneous material having polarity. 5. The adhesive of polypropylene and a heterogeneous material having polarities according to claim 1, wherein the non-volatile components in each of the liquids A and B have the following composition. Non-volatile component composition of liquid A Chloroprene rubber 70 to 90 wt%, low chlorinated isotactic polypropylene with chlorine content of 8 to 30 wt% 30 to 10 wt% Non-volatile component composition of liquid B Chlorine content 60 10% to 50% by weight of highly chlorinated polypropylene with a chlorine content of 60% by weight or more, or 90% of highly chlorinated polyethylene or chlorinated rubber
50% by weight 6. The following composition is contained as a non-volatile component, The solvent is a solvent selected from the group consisting of aromatic hydrocarbon-based solvents and chlorinated hydrocarbon-based solvents, or a mixed solvent of one or more selected from them, or a mixed solvent of these solvents with another solvent as a main component. When using an adhesive consisting of two parts,
Liquid A is applied to the adhered surface of a polypropylene molded product, and liquid B is applied to the adhered surface of a product of a different material, and both applied surfaces are overlapped and pressure-bonded. Polypropylene and a heterogeneous material having polarity. Bonding method.