JPS61152755A - Primer composition for polypropylene resin - Google Patents

Abstract

PURPOSE:A composition that is obtained by adding a specific polypropylene and a specific solid resin, thus showing good tackiness for a long period of time and giving coating films of high solvent resistance. CONSTITUTION:(A) 50-90pts.wt. of a chlorinated polypropylene which may contain up to 70wt% of an ethylene-vinyl acetate copolymer of 5-40wt% vinyl acetate content, have 10-50wt% chlorine content and 2-70 acid value based on the solid content and/or another chlorinated polypropylene of 2-150 hydroxyl value base on the solid content are combined with (B) 50-10pts.wt. of a resin which is solid at room temperature and soluble in solvents selected from aromatic, aliphatic, alicyclic hydrocarbons, ketones, esters, alcohols and chlorinated hydrocarbons and can give tackiness to component A. The component B is, e.g., 100% phenolic resin or rosin-modified phenolic resin.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a new and useful primer composition for polypropylene resins, and the object of the present invention is to prepare such polypropylene resins for untreated It has a function as a primer for the polypropylene resin material when used as a material as is, that is, without any various surface treatments to impart paintability.
Moreover, it is an object of the present invention to provide a resin composition having good adhesion and solvent resistance.

[Prior art and problems to be solved by the invention] Paints made from alkyd resins, acrylic resins, epoxy resins, etc., which have been used in the past, cannot be applied to various molded products made from crystalline polyolefins with low polarity. It has almost no adhesion ability.

For this reason, when painting these polyolefin materials, use a maleic anhydride modified product of atactic polypropylene or ethylene
It has been proposed to use propylene copolymers modified with maleic anhydride, but although they have good adhesion to the materials listed above, they also have poor adhesion to the top coat layer. Moreover, it has a drawback in solvent resistance.

On the other hand, a method is known in which chlorinated polyolefin itself is used as a primer and an acrylic resin is applied as a top coat layer, but even with this method, the glabella adhesion with the top coat layer and the solvent resistance It has the disadvantage of poor adhesive properties and long-term durable adhesion.

[Means for solving problems]

However, the inventors of the present invention have conducted extensive studies in view of the various drawbacks of the conventional techniques as described above, and have found that chlorinated polypropylene containing acid groups (carboxyl groups) and chlorinated polypropylene containing hydroxyl groups A composition containing a mixture with a solid resin capable of imparting tackiness and also a specific ethylene-vinyl acetate copolymer was prepared without any surface treatment. It has excellent adhesion even to polypropylene resins,
Moreover, the present invention was completed based on the discovery that the primer has excellent properties such as adhesion to top coats (interlayer adhesion) and adhesion during cold and hot cycles.

That is, in the present invention, as essential components, (A) chlorinated polypropylene (a-1) having a chlorine content of 10 to 50% by weight and an acid value of 2 to 70 per solid content, and/or 50 to 90 parts by weight of chlorinated polypropylene (a-2) having a hydroxyl value of 2 to 150, and (B) solid at room temperature and aromatic, aliphatic, alicyclic, or ketone. 50 to 10 weight of a resin capable of imparting tackiness to the chlorinated polypropylene (a-1) and (a-2), which is soluble in a solvent selected from the group consisting of polypropylene, ester, alcohol, and chlorine. and the above component (A) has a vinyl acetate content of 5 to 5.
50% weight ethylene vinyl acetate copolymer (a-3)
0 to 70% by weight of the chlorinated polypropylene (a-1
) and/or (a-2>) in an amount of 100 to 30% by weight.

Here, the above-mentioned polypropylene resin refers to a propylene homopolymer or copolymer containing propylene as an essential constituent unit, and the most representative examples thereof include polypropylene homopolymer. , ethylene propylene copolymer or ethylene propylene diene terpolymer.

In addition, the above-mentioned chlorinated polypropylene (a-1) is
Refers to chlorinated polypropylene having a chlorination rate of 10 to 50% by weight, preferably 10 to 40% by weight, and an acid value of 2 to 70, preferably 5 to 50 per resin solid content,
On the other hand, the above-mentioned chlorinated polypropylene (a-2) has a chlorination rate of 10 to 50% by weight, 10 to 40% by weight,
It also refers to chlorinated polypropylene having a hydroxyl value of 2 to 150, preferably 5 to 110, per resin solid content.

At that time, if the chlorination rate of the chlorinated polypropylene (a-1) or (a-2) exceeds 50% by weight, the adhesion to various polypropylene resin materials as mentioned above will decrease. On the other hand, if the chlorination rate is less than 10% by weight, it is not preferable because it will lack storage stability, and if the acid value of the chlorinated polypropylene (a-1) is less than 70 If the acid value exceeds 2, the adhesion to various polypropylene resin materials will decrease, and conversely, if the acid value is less than 2, the interlayer adhesion with the top coat layer will deteriorate, which is preferable. On the other hand, the chlorinated polypropylene (a-2
) If the hydroxyl value of the chlorinated polypropylene (a-2) solution exceeds 150 fc, it will cause problems in the stability of the chlorinated polypropylene (a-2) solution itself and its adhesion to various polypropylene resin materials; is less than 2,
This is not preferable because the adhesion between the eyebrows and the top coat layer becomes poor.

By the way, as the component (A) which is the first essential component constituting the composition of the present invention, chlorinated polypropylene (a-1) and/or (a-2) listed above can be used.
) alone can sufficiently achieve the object of the present invention, but if further flexibility is required, such chlorinated polypropylene (a-1) and/or (a) can be used as the component (A). -2) may be mixed with a specific ethylene vinyl acetate copolymer (a-3) as described below within a range of up to 70% by weight.

As such ethylene vinyl acetate copolymer (a-3), one having a vinyl acetate content of 5 to 50% by weight, preferably 10 to 45% by weight is particularly suitable.

If this vinyl acetate content is less than 5% by weight,
The interlayer adhesion with the top coat layer will be reduced, and if the amount exceeds 50% by weight, the obtained composition of the present invention will have a disadvantage in solvent resistance.

And the chlorinated polypropylene (a-1) and (
The mixing ratio of the ethylene vinyl acetate copolymer (a-3) to a-2) is 0 to 70% by weight of the ethylene vinyl acetate copolymer (a-3), chlorinated polypropylene 1) and (a-2). -2) from 100 to 30% by weight, preferably from 0 to 50% by weight to 100 to 50% by weight.

If the amount of the ethylene-vinyl acetate copolymer (a-3) exceeds 70% by weight, it is not preferable because the adhesion to the various polypropylene resin materials mentioned above will be reduced.

Chlorinated polypropylene (a
-1) and/or (a-2) 100 to 30% by weight and 0 to 7% of ethylene vinyl acetate copolymer (a-3)
Component (A) consisting of 0% by weight alone has excellent adhesion to the various polypropylene resin materials listed above, but the copolymerization of certain types of polypropylene resins In the case of molded products obtained using coalescence, it is observed that the adhesion after the hot water resistance test decreases in some cases.

As a measure to improve the decrease in adhesion after the hot water resistance test or to further improve the solvent resistance of the primer, chlorinated polypropylene which is compatible with the component (A) and which is in the component (A) has been developed. (a-1) and/or (
a-2) A solid resin that can impart adhesion to various polypropylene resin materials, that is, a solid resin that is solid at room temperature and is aromatic, aliphatic,
Adhesiveness can be imparted to the chlorinated polypropylene (a-1) and (a-2), which is soluble in a solvent selected from the group consisting of alicyclic type, ketone type, ester type, alcohol type and chlorine type. The solid resin (B) is used as the second essential component constituting the composition of the present invention, and the solid resin (B) is
10 to 50 parts by weight, preferably 10 to 50 parts by weight
It is preferable to blend the compound in a proportion of 40 parts by weight, and by such a method, a cured coating film having good adhesion to all polypropylene resin materials and excellent solvent resistance can be obtained.

Here, as a representative example of the solid resin (B), 1
00% carbonic acid resin (phenolic resin), natural resin-modified carbonic acid resin such as rosin-modified phenolic resin, natural resin-modified maleic acid resin such as rosin-modified maleic acid resin, various xylene resins, ketone resins, terpene polymer resins (terpene resin), α-pinene polymer, terpene/phenol polymer, various rosin resins, coumaron resin, coumaron/
Examples include indene polymers (coumarone/indene resin), alicyclic saturated hydrocarbon resins, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, hydrogenated alicyclic hydrocarbon resins, and C6 distillate petroleum resins. However, these may be used alone or as a mixture of two or more.

The amount of the solid resin (B) to be used should be 50 parts by weight or less, and more preferably, since the flexibility of the resulting coating film will be insufficient if it exceeds 50 parts by weight. is suitably within the range of 10 to 40 parts by weight.

The thus obtained primer composition of the present invention has excellent long-term adhesion and adhesion in a broad sense such as glabellar adhesion with the top coat layer, and also forms a coating film with excellent solvent resistance. It provides a cured coating film with high performance, and among these, the hydroxyl group-containing chlorinated polypropylene primer composition is known as Parnock DN-950.
By curing with various isocyanate prepolymers such as J (non-yellowing isocyanate prepolymer manufactured by Dainippon Ink & Chemicals), there will be no adverse effect on interlayer adhesion with the top coat layer. This is particularly desirable since it can also improve the solvent resistance of the primer composition of the present invention.

〔Example〕

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples. In the following, all parts and percentages are based on weight unless otherwise specified.

Example 1 A reactor equipped with a stirrer and a cooler was equipped with [Bar Drain 1]
4MLJ (Toyo Kasei Kogyo special chlorinated polypropylene)
225.8 parts of maleic anhydride copolymer; solid content -31%, chlorine content = 24.5%, acid value -3.5], 20 parts of toluene and "Kumaron Resin V-120" (Nippon Steel) Add 30 parts of Cumaron resin manufactured by Kagaku ■, raise the temperature inside the vessel to 50°C, and stir until it becomes a homogeneous solution. When the solution becomes homogeneous, add 124.2 parts of xylene to reduce the solid content to 2.
A 6.3% resin solution was obtained.

Next, the resin solution: "Tie Bake CR-93J: rMA-100J-70? 29" was added to this resin solution.
．． Pigments were blended so that the ratio of solid content by weight was 4:o, os (solid content weight ratio), and a paint was prepared by a conventional method.

Here, the above-mentioned "Tie Bake CR-93J" is a rutile type titanium oxide manufactured by Ishihara Sangyo ■, and the above-mentioned rMA-
100" is a carbon black specially manufactured by Mitsubishi Chemical Industries.

After that, the resulting paint was diluted with a thinner of xylene:ethyl acetate-50:5G (weight ratio) using an Iwata cup for 12 seconds. After 10 minutes of spray painting on a sheet made from a polypropylene homopolymer manufactured by Mitsubishi Yuka Special Co., Ltd., a sheet made from Acrydic A-800J (an acrylic polyol manufactured by Dainippon Ink & Chemicals) and Parnock DN-950J was spray-painted. Prepared white paint - □ with a pigment concentration (PWC) of 35% using Tybake CR-93J was mixed with a thinner of xylene:ethyl acetate - 50? Apply the diluted solution to the previously painted sheet, let it set for 10 minutes, and then heat it to 60℃.
It was forced to dry for 30 minutes.

After 3 days of drying, a comprehensive evaluation of the physical properties of the paint film was made from both the sheet coated with the primer composition and the sheet coated with a top coat layer on top of the primer coat. I did it.

The results are summarized in Table 1.

Example 2 In place of Pardren 14MLJ, 350 parts of Super Chron 5-64 (chlorinated polypropylene/maleic anhydride copolymer manufactured by Sanyo Kokusaku Pulp ■; solid content = 2)
A resin solution having a solid content of 19.8% was obtained in the same manner as in Example 1, except that the resin solution was changed to use 0%, a chlorination rate of -24.5%, and an acid value of -3.2].

From now on, except for changing to use this resin solution,
A paint was prepared in the same manner as in Example 1, and the physical properties of the paint film were evaluated. The results are summarized in Table 1.

Example 3 Example 1 except that the same amount of Veracasite fill-60Tj (natural resin-modified maleic acid resin manufactured by Dainippon Ink and Chemicals) was used instead of Coumaron resin V-120J. Similarly, the solid content is 25
．． A 3% resin solution was obtained.

Next, except for changing to use this resin solution,
Thereafter, it was made into a paint in the same manner as in Example 1, and the physical properties of the paint film were evaluated. The results are summarized in Table 1.

Example 4 466.7 parts of “Pardren 14MLJ”
Birdren 14LLB-AHloj (chlorinated polypropylene/β-hydroxyethyl acrylate copolymer manufactured by the same company; solid content - 17.3%, chlorine content - 24%)
A resin solution having a solid content of 19.5% was obtained in the same manner as in Example 1, except for using a resin with a hydroxyl value of -6.7''.

Next, except for changing to use this resin solution,
Thereafter, it was made into a paint in the same manner as in Example 1, and the physical properties of the paint film were evaluated. The results are summarized in Table 1.

Example 5 A reactor equipped with a stirrer and a cooler was equipped with a
193.5 copies of 4MLJ, [Lpax 150J
(Ethylene vinyl acetate copolymer manufactured by Mitsui Polychemical ■; vinyl acetate content - 33%), 20 parts of Cumaron resin V-120J, 30 parts of toluene, and 23 s, s parts of xylene were prepared. , set the temperature inside the vessel to 50
℃ and stirred until a homogeneous solution was obtained.

A resin solution with a solid content of 21.3% was obtained.

Next, except for changing to use this resin solution,
A paint was prepared in the same manner as in Example 1, and the physical properties of the paint film were evaluated.

The results are summarized in Table 1.

Comparative Example 1 ``466.7 parts of ``Instead of Pardren 14MLJ''
Example 1 except that Pardren 14LLBJ (chlorinated polypropylene manufactured by the same company; solid content -15%, chlorination rate -27%) was used, and the use of xylene was completely omitted during this preparation. A control resin solution having a solid content of 19.8% was obtained in the same manner as above.

Next, except for changing to use this resin solution,
Thereafter, it was made into a paint in the same manner as in Example 1, and the physical properties of the paint film were evaluated. The results are summarized in Table 1.

Comparative Example 2 Absent any use of Cumaron Resin V-120J, and therefore 'Padren 14MLJ: rTiebake CR
-93J: rMA-100J-70:29.4:0.
A paint was produced in the same manner as in Example 1, except that the composition ratio was changed to 0.6 (solid content weight ratio), and the physical properties of the paint film were evaluated using the control primer composition thus obtained. went. The results are summarized in Table 1.

〔Effect of the invention〕

As is clear from the results in Table 1, the primer composition of the present invention has excellent adhesion to an inert polypropylene resin material that has not been subjected to any surface treatment, and also has excellent adhesion to the top coat layer. It is known that it provides a useful coating film with excellent adhesion to the glabella.

Claims (1)

[Scope of Claims] (A) The ethylene vinyl acetate copolymer (a-3) having a vinyl acetate content of 5 to 50% by weight may be contained in a range of up to 70% by weight, and a chlorine content of 10% by weight. Chlorinated polypropylene (a-1) containing ~50% by weight and having an acid value of 2 to 70 per solid content and/or chlorinated polypropylene (a-2) having a hydroxyl value of 2 to 150 per solid content
(B) is solid at room temperature and is selected from the group consisting of aromatic, aliphatic, alicyclic, ketone, ester, alcohol, and chlorine. A primer for polypropylene resin, comprising as an essential component 50 to 10 parts by weight of a resin that is soluble in a solvent and can impart tackiness to the chlorinated polypropylenes (a-1) and (a-2). Composition.