JPS59166534A - Coating agent - Google Patents

Abstract

PURPOSE:To provide a coating agent composed of a specific chlorinated product of propylene low-polymer added with maleic anhydride, and capable of bonding firmly to a polyolefin molded article and forming a coating film having excellent oil resistance, weather resistance and rust-preventing property. CONSTITUTION:A propylene low-polymer having an average molecular weight of 2,000-3,000, preferably 1,500-2,500 and a melt flow rate of preferably >=1,000 (preferably thermally cracked propylene homopolymer or copolymer) is added with maleic anhydride (preferably the amount of the bonded maleic anhydride is 1-7wt%) and then chlorinated (preferably the amount of bonded chlorine is 10- 35wt%). The obtained chlorinated propylene low-polymer added with maleic anhydride is dissolved in a solvent (e.g. toluene) to obtain the objective coating agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating agent. More specifically, it relates to coating agents suitable for polyolefins.

In recent years, various plastics have come to be widely used for gear vignettes in automobile parts and home appliances, but polyolefins, especially polypropylene, are cheap, lightweight,
Due to its advantages such as good solvent resistance, its applications are being developed extensively. However, from the left, polypropylene has poor polarity, making it difficult for various coating materials to adhere to it. For this reason, unsaturated compounds have recently been added to chlorinated polypropylene? Reactions and chlorinated maleic anhydride-grafted polypropylene have been proposed as primers for polypropylene. However, these are originally modified polypropylene with a high molecular weight, and although they have some degree of adhesion to both the polypropylene base material and the two-coat paint, they have improved performance (for example, adhesion to the two-coat paint, Oil resistance,
2) Other vehicle components to improve weatherability, etc.
For example, when used in combination with or mixed with epoxy, urethane, acrylic, or alkyd resins, it has poor compatibility with these resins and is difficult to form into a uniform blend.

As a result, when the compound is dissolved in an organic solvent and made into a solution,
There are problems such as poor stability, poor coating workability, and decreased appearance, smoothness, and adhesion of the resulting coating film.

As a result of intensive studies to solve these problems, the inventors of the present invention found that low molecular weight propylene polymers, especially those obtained by thermal decomposition, are modified products of propylene low polymers obtained from all starting materials. The inventors have discovered that the above two problems can be solved by the use of derivatives or derivatives thereof, and have arrived at the present invention.

That is, the present invention provides a chlorinated product of a propylene-based low polymer to which maleic anhydride has been added (however, the average molecular weight of the propylene-based low polymer before addition of maleic anhydride) The average molecular weight of the low polymer is 2.00 to 80,00.
0, preferably 3,500 to 25,000.

If the average molecular weight is less than 2,000, the final chlorinated product will be brittle and sticky, making it unsuitable as a coating agent. Average molecular weight is 30. If it exceeds OOO'i, it will have poor compatibility with other vehicle resins to be mixed, and the resulting coating compound will not have sufficient stability, resulting in not only poor coating workability but also poor smoothness and adhesion. A good coating film cannot be obtained. For example, the average molecular weight of propylene-based low polymers is
It can be dissolved in di-chlorobenzene at a concentration of about 0.3 weight/volume and measured by gel permeation chromatography at 185'C. Further, the melt flow rate of the propylene-based low polymer is usually 500 or more, preferably 1. It is OO0 or more. If the melt flow rate is less than 500, compatibility with other resins tends to decrease.

Propylene low polymers include propylene homopolymers, propylene and ethylene, butene-1, pentene-1
, copolymer with other α-olefin (carbon number usually 2 or more, preferably 2 to 6) comonomer such as hexene-1, heptene-1 (copolymer preferably has a comonomer content of 20 moles) v % or less ) can be given. The propylene-based low polymer may be one of the following types: atactic, atactic, and syndiotactic.

Propylene-based low polymers may be those obtained by thermal decomposition (thermal degradation) of high molecular weight propylene-based polymers, or those obtained by normal telomerization (single or co-image polymerization of propylene). But that's fine. Among these,
Those obtained by thermal decomposition are preferred because the addition reaction of maleic anhydride is fast and high quality products can be obtained. For example, a method of thermally decomposing high molecular weight propylene alone or a copolymer (molecular weight usually 100,000 to 2,000,000) in the presence of an inert gas or, if necessary, in the presence of steam,
One example is a method of heating at .degree. C. for several hours. For example, the pyrolysis method is described in US2928797.282.
8296,2885659. Br'1t-110829
5.Special public school 1977-! 11168 etc.

The amount of chemically bonded maleic anhydride in the maleic anhydride-added propylene low polymer is usually 0.5 to 1.
0% by weight, preferably 1 to 7% by weight. If the amount of maleic anhydride is less than 0.5% by weight, the compatibility with other vehicles to be mixed will decrease, and the adhesion with the top coat will be insufficient. If it exceeds 10% by weight, water resistance and flexibility will decrease.

Maleic anhydride-adducted propylene-based low polymers are prepared by adding propylene-based low polymers in an inert gas atmosphere in the presence or absence of aromatic and/or chlorine-based solvents, and in the presence or absence of radical-generating catalysts (peroxides). , azotolyles, etc.), usually at 120°C to 2°C.
It can be obtained by heating and dissolving at 20° C., adding maleic anhydride in portions or all at once, and causing a reaction (graft polymerization).

In the chlorinated maleic anhydride-added propylene low polymer, the amount of bound chlorine in the chlorinated product is usually 5 to 50 parts by weight, preferably 10 to 35 parts by weight. If the amount of combined chlorine is less than 5% by weight, the solubility in the solvent is insufficient,
If it exceeds 50% by weight, weather resistance will decrease. Chlorinated product of maleic anhydride-added propylene-based low polymer 1d By a known method, for example, a maleic anhydride-added propylene-based low polymer is heated and dissolved in a chlorinated solvent such as carbon tetrachloride, and the chlorination is accelerated at a temperature of, for example, 60°C. It can be obtained by introducing chlorine gas into a reaction solution and reacting at a temperature of 120°C to 120°C. The reaction may be carried out by irradiating light for the purpose of increasing the reaction rate, or may be carried out under pressure.

The obtained chlorinated product of maleic anhydride-added propylene-based low polymer is a pale yellow to yellow solid, and its softening and cooling (ring and ball type) are usually 130°C to 170°C, and the melt viscosity (160°C) is usually 50 to 50,000 cps. It is.

The coating agent of the present invention contains a chlorinated maleic anhydride-added propylene-based low polymer.
Usually aromatic solvents (toluene, xylene, cumene, etc.)
It is used as a solution in a suitable concentration (usually 1 to 30% by weight) in a solvent such as a chlorinated solvent (Schiff ethylene, perchlorethylene, dichlorobenzene, etc.). If the use of solvents is undesirable for safety and hygiene reasons, use a chlorinated maleic anhydride-adducted propylene-based low polymer as a surfactant such as a nonionic, anionic, or cationic surfactant (nonylphenol 7-leoxyalkyne ether).

An aqueous emulsion (solid content usually 1 to 20% by weight) may be prepared using a higher alcohol oxyalkylene ether, sodium argylbenzenesulfonate, etc.).

The coating agent of the present invention includes epoxy-based, urethane-based, acrylic-based, and alkyd-based coating agents commonly used as paint vehicles for the purpose of improving the solvent resistance, water resistance, heat resistance, smoothness, etc. of the coating film. It is preferable to appropriately mix a cooling resin.

These resins are described in "Synthetic Resin Paints" (Kobunshi Publishing Co., Ltd., published on December 10, 1960). The weight ratio of chlorinated material and other resins during mixing is usually 3:97.
~97:8. Preferably it is 5:95 to 95:5.

Further, these coating agents may be blended with ordinary paint additives such as pigments and dispersants.

Its amount is usually less than 10% by weight in the coating agent.

The material (coating base material) for the coating agent of the present invention is polyolefin (especially propylene polymer).
is preferred, as well as other plastics, wood, paper,
It can also be used for metals, etc.

The coating agent may be applied to the substrate by a conventional method, for example, the coating agent may be applied to the object by a conventional coating method such as dipping, spraying, or dipping. The coating amount is usually 5 to 40 microns in terms of dry film thickness. Drying is usually done at room temperature for 5 to 20 minutes, then 70 to 13 minutes.
This is done by heating at 0°C for 10 to 45 minutes. In addition to applying directly to the substrate (one coat), it is also possible to further apply the applied and dried film (two coats or more). If necessary, a topcoat is applied to the coating film thus applied. The top coating agent may be thermoplastic or thermosetting, and includes commonly used paints such as alkyd, acrylic/epoxy, urethane, and acrylic urethane-1. These paints are also described in the above-mentioned "synthetic resin paints".

The coating agent of the present invention has the following effects.

(1) When the coating agent of the present invention is mixed with other resins, it has good compatibility with those resins, and a coating agent with excellent storage stability can be obtained.

(2) When the coating agent of the present invention is coated on a base material, particularly a polyolefin molded product, a coating film that firmly adheres to the surface of the polyolefin molded product and has excellent properties such as oil resistance, weather resistance, and rust prevention can be obtained. It will be done. In addition, when the top coat agent is further coated, it is also superior to the top coat agent.
It has excellent adhesion. In particular, when the coating agent of the present invention is blended with other resins, the above performance is improved.

(3) Compared to conventional products, the coating agent of the present invention is soluble in solvents, and the viscosity of the coating agent obtained by dispersing it in bamboo water is low, making it particularly easy to apply by spraying.Also, chlorinated It has improved solubility in solvents compared to polypropylene reacted with maleic anhydride.

The coating agent of the present invention can be preferably used as a coating agent for polyolefin molded articles, particularly propylene polymer molded articles. Also, adhesives for polyolefin molded products,
It can also be used as a printing ink.

Hereinafter, the present invention will be further explained with reference to production examples, comparative production examples, examples, and test examples, but the present invention is not limited to chickens. In addition, parts in production examples, comparative production examples, examples, and test examples indicate parts by weight unless otherwise specified.

Production Example 1 High molecular weight propylene homopolymer (average molecular weight 1250
300 parts of a propylene homopolymer having an average molecular weight of 10,000 obtained by thermally decomposing 00), and 3 maleic anhydride.
0 part was charged into a device equipped with a reflux tube, 700 parts of xylene was added, and the system was purged with nitrogen. While stirring, the temperature was raised to 150°C while introducing a small amount of nitrogen, and after uniformly dissolving the system, 165 parts of dicumyl peroxide was added over 3 hours. After continuing the reaction for another 4 hours, initially at normal pressure, Then 180℃
, xylene and unreacted maleic anhydride were distilled off over 2 hours under reduced pressure of 8 msHg. The obtained maleic anhydride-added propylene low polymer had a melt viscosity of 16 at 160°C.
00CI) S% A yellow solid with a ring and ball softening point of 154°C,
7Jl''1 volume with maleic anhydride was 3.8 parts by weight.

Next, the maleic anhydride-added propylene low polymer 200
1 part, and 800 parts of carbon tetrachloride were charged into an apparatus equipped with a flow tube, heated to 65°C to 70°C to uniformly dissolve them, and then 35 parts of chlorine gas per hour was introduced into the reaction solution for 4 hours. After chlorination, residual chlorine and carbon tetrachloride in the reaction solution were first distilled off at normal pressure and then at 160°C and under reduced pressure of 8ypHg over 2 hours. The obtained chlorinated maleic anhydride propylene low polymer 1d, melt viscosity at 160°C 112°C
ps, i It was a yellow solid with a ball softening point of 150°C, and the amount of combined chlorine was 21.5 parts by weight.

Production Example 2 Propylene-based low polymer was obtained by thermally decomposing a high molecular weight propylene-based polymer (average molecular weight: 165,000). The same method as in Production Example 1 was used except that a propylene-ethylene block copolymer with an ethylene content of 10 moles was used, and the amount of maleic anhydride added was 52% by weight.
A chlorinated product of a maleic anhydride-added propylene-based low polymer having a combined chlorine i 24 B weight % was obtained. This modified low polymer had a melt viscosity of 580 C98% at 160°C and a ring and ball softening point of 146°C.

Production Example 3 A propylene-butene-1 block copolymer with an average molecular weight Ji of 28,000 and a butene-1 content of 20 moles obtained by thermally decomposing a high molecular weight propylene polymer (average molecular weight 112,000) as a propylene-based low polymer. The amount of maleic anhydride added was 2.8 in the same manner as in Production Example 1 except that
A chlorinated product of a maleic anhydride-adducted propylene-based low polymer having a combined chlorine content of 32.2 parts by weight was obtained. This modified low polymer had a melt viscosity of 41,000 cps at 160°C and a ring and ball softening point of 158°C.

Comparative Production Example 1 The same method as Production Example 1 was used except that a propylene homopolymer with an average molecular weight of 97,000 was used as the propylene polymer, with an amount of maleic anhydride added of 35% by weight and an amount of bound chlorine of 19.8.
Part by weight of a chlorinated maleic anhydride-added propylene homopolymer was obtained. This modified polymer had a melt viscosity of 5.5 million cps at 160°C and a ring and ball softening point of 162°C.

Example 1 The following two series of coating agents were prepared using the chlorinated maleic anhydride-added propylene polymers obtained in Production Examples 1 to 3 and Comparative Production Example 1.

A. Chlorinated maleic anhydride-grafted propylene polymer was added to 1-1% of the solid content so that the solid content was 5 parts by weight.
Solution in toluene.

B 71 parts of chlorinated maleic anhydride-added propylene polymer, 871 parts of dimer acid-based epoxy resin (Epicor)
, manufactured by Shell Chemical Co., Ltd.) and 28 parts of dimer acid polyamide resin (Polymide H-2270. Amine value 144, manufactured by Sanyo Chemical Industries, Ltd.) and dissolved in toluene so that the solid content concentration becomes 5% by weight. solution.

Test Example 1 Polypropylene (Ube Polypropylene J-309G) was molded by injection molding, 100 maX 100rnx
A sheet of 2 ffJl+ was obtained. Each of the sheets was immersed in isopropyl alcohol for 1 minute in a room, and then dried in a room for 5 minutes for degreasing. Thereafter, coating agents A and B according to Example 1 were spray applied to the degreased sheet, dried at room temperature for 5 minutes, and then dried and cured in a garnish dryer at 90° C. for 30 minutes. A two-component non-yellowing acrylic urethane resin paint (Sunbren TC-Q7, manufactured by Ohyo Kasei Kogyo Co., Ltd.) was mixed with a base agent and a curing agent at a ratio of 2:1, and sprayed on each of the primed sheets for 10 minutes. After drying at room temperature, use a circulation dryer at 90C.
Dry for a0 ml and cure. Each coated sheet thus obtained was left at room temperature for 7 days and then subjected to the following tests. The results are shown in Table 1.

(1) Appearance of coating agents The appearance of coating agents A and B immediately after preparation was observed with the naked eye.

(2) Storage Stability of Coating Agents Coating agents A and B were placed in a glass bottle, and after being left at room temperature for 6 months, the appearance was visually observed.

(3) Initial adhesion A cellophane tape test using J-K5K5400 was conducted on the coating surface of each coated sheet.

(4) Water resistance Each coating sheet) After 240 hours immersion in 40℃ warm water, 1
After drying at room temperature for an hour, a cellophane tape test was conducted.

(5) Volatile oil resistance Each coated sheet was immersed in a 1/1 mixed solvent of n-hexane/n-hebutane at 20° C. for 24 hours, dried at room temperature for 1 hour, and then subjected to a cellophane tape test.

(6) Weather resistance Each coated sheet was subjected to a Sunshine Carbon Type Tweezerometer for 1,000 hours and then left at room temperature for 1 hour to conduct a Govan cellophane tape test based on JIS K5400.

Claims (1)

[Claims] 1. Chlorinated propylene-based low polymer with maleic anhydride added (however, the average molecular weight of the propylene-based low polymer before addition of maleic anhydride is 2.0002; The coating agent according to claim 1, wherein the polymer is a pyrolyzable propylene homopolymer or copolymer.λ The content of chemically bonded maleic anhydride in the low polymer is 0.5 to 10% by weight of the coating agent according to claim 1 or 2. 4. The coating agent according to claims 1 to 3, wherein the amount of combined chlorine in the chloride is in the range of 5 to 5ON. 5. The coating according to any one of claims 1 to 4, wherein the propylene-based low polymer has a melt flow rate of 500 or more before addition of maleic anhydride. agent.