JPS5975958A - Composition for polypropylene resin - Google Patents

Abstract

PURPOSE:To provide the titled compsn. capable of imparting excellent adherability, apperance and resistance to flexing, impact, water, moisture and gasoline to PP resins, consisting of a specified chlorinated polyolefin and an epoxy compd. or resin. CONSTITUTION:A polyolefin having a saponification value of 6-60 obtd. by modifying a polyolefin resin with an unsaturated polycarboxylic acid or its anhydride in the presence of a free radical generating agent is dispersed or dissolved in a chlorinated solvent. Chlorine gas is caused to bubble therethrough at 50-120 deg.C in the presence of a catalyst or under the irradiation of ultraviolet light to obtain a chlorinated polyolefin (A) having a degree of chlorination of 10-50wt%. 0.5-50pts.wt. compd. having at least two epoxy groups per molecule or resin such as ethylene glycol glycidyl ether is blended with 100pts.wt. compoent A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a coating composition used for the protection or cosmetic purposes of polypropylene resins, such as polypropylene, ethylene propylene copolymers, ethylene propylene diene copolymers, etc., and more specifically relates to polypropylene resins. The present invention relates to a coating composition that satisfies adhesion with polypropylene resin, appearance, gasoline resistance, bending resistance, impact resistance, moisture resistance, water resistance, etc. when applied to sheets and molded articles.

Polypropylene resin has excellent properties such as chemical resistance, ozone resistance, heat resistance, water resistance, and good electrical properties, and because it is lightweight and inexpensive, it is used in industrial applications such as home appliances and automobile parts. It has only just begun to be widely used as a material9, and is one of the materials whose demand is most expected to grow in the future. However, despite having these characteristics, when it comes to automobile parts, for example, various plastics are being used to reduce weight from the perspective of energy conservation, and the amount of plastic used is increasing year by year. Its use is limited to some parts. One of the reasons preventing its widespread use is that polypropylene resin is non-polar and crystalline, making it extremely difficult to paint or adhere. For these reasons, there is a strong desire to develop a coating composition that has good adhesion to polypropylene resins. When printing or adhering to polypropylene resin, adhesion has traditionally been improved by treatments such as corona discharge, but these methods cannot uniformly process molded products with complex surfaces. There is a drawback. Therefore, various primer compositions that have good adhesion to polypropylene have been proposed as methods for painting without these pretreatments. For example, Special Publication No. 49-18089, Special Publication No. 49-521
Examples include a primer composition shown in No. 4 consisting of a cyclized rubber, an aromatic petroleum resin, an oil-soluble phenol resin, a coumaron indene resin, and a chlorinated polyolefin. However, even though these have good adhesion to polypropylene, they have insufficient adhesion to top coats. Particularly in recent years, paints that are used outdoors, such as on automobiles and motorcycles, have come to be required to have stronger adhesion, weather resistance, and gasoline resistance. Regarding these, as seen in JP-A No. 56-76433, compounds containing chlorinated polyolefin, basic nitrogen-containing acrylic copolymer, and epoxy resin,
A coating composition was proposed in which an epoxy resin was blended with a copolymer of a chlorinated polyolefin, a basic nitrogen-containing acrylic monomer, and other acrylic monomers, as seen in JP-A-56-50971. However, in order to obtain satisfactory coating performance, it is necessary to reduce the chlorinated polyolefin content f' in the paint resin. This causes problems in adhesion to system resins.

Therefore, in order to solve the above problems, the present inventors
Focusing on the fact that carboxyl groups or acid anhydride groups react with epoxy groups, saponification was performed by modifying with one or more compounds selected from the group consisting of unsaturated polycarbonate (I) or its acid anhydrides. The value is 6-60. Chlorinated polyolefin (+) (!:, compound or resin having 2 or more epoxy groups per molecule (1) t- The coating composition as the main component is It was discovered that the polypropylene resin exhibits excellent adhesion, appearance, bending resistance, impact resistance, moisture resistance, and water resistance, as well as good gasoline resistance, and was therefore excluded from the present invention.

Incidentally, the fact that the poly-α-olefin chlorine compound containing a carboxyl group can be used as an undercoat means that one or more compounds selected from the group consisting of unsaturated polycarboxylic acids or their acid anhydrides used in the present invention. A chlorinated polyolefin (+) obtained by completely chlorinating a polyolefin modified with can be produced by a known method. One example of its production method includes polyolefin resins such as crystalline polypropylene, amorphous polypropylene, polybutene-1, polypentene-1,4-methylpentene-
[-
1 If necessary, a molten polyolefin resin whose viscosity has been reduced by thermal decomposition is modified with an unsaturated polycarboxylic acid or its acid anhydride in the presence of a radical generator in a batch or continuous manner, and then immersed in a chlorinated solvent. It can be obtained by dispersing or dissolving the compound and causing a reaction by blowing chlorine gas at a temperature of 50 to 120° C. under pressure or normal pressure in the presence of a catalyst or under irradiation with ultraviolet rays.

Examples of radical generators used in the modification reaction include di-tert-butyl peroxide, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, and di-tert-butyl peroxide.
These include peroxides such as t-butyl ciber phthalate and azonitrile such as azobisisobutyronitrile and azobisisopropionitrile.

Examples of unsaturated polycarboxylic acids and acid anhydrides used in the modification reaction include maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, fumaric acid, mesaconic acid, itaconic acid, itaconic anhydride, and aconite. There are many types of acids and aconitic anhydrides.

The saponification value of the polyolefin modified with the unsaturated polycarboxylic acid and its acid anhydride used in the present invention is at least 6 or more, preferably 10-60.

If the saponification value is too low, the effect of crosslinking with the epoxy resin will be small and solvent resistance will decrease. Moreover, if the saponification value is too high, adhesion to polypropylene resin will deteriorate. Chlorinated polyolefin (1) obtained by fully chlorinating polyolefin modified with unsaturated polycarboxylic acid and its acid anhydride
The degree of chlorination is 1. It can be used between Owt% and 5Qwt%, preferably between 15wt% and 35wt%.
It is. If the degree of chlorination is low, the solution condition will be poor, and if the degree of chlorination is high, the adhesion to the polypropylene resin will be poor.

The compound or resin (n) having two or more epoxy groups per molecule used in the present invention is a chlorinated polyolefin (+1 and Those with good compatibility are preferred, such as bisphenol A type and glycidyl ether type of polyhydric alcohols, such as ethylene glycol glycidyl ether, propylene glycol glycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, and other olefins. If it contains two or more epoxy groups in one molecule, such as a cycloaliphatic epoxy resin obtained by oxidizing with be able to.

The blending ratio of the chlorinated polyolefin (+) obtained by chlorinating polyolefin modified with these unsaturated polycarboxylic acids and their acid anhydrides and the epoxy group-containing compound or resin (ri) is 100 by weight. : A range of 0.5 to 50 is desirable for implementing the present invention. This is because if the epoxy group-containing compound or resin (l) is less than 0.5, the solvent resistance will not be sufficient, whereas if it exceeds 50, the adhesion to polypropylene resin sheets and molded objects will decrease. .

Furthermore, in order to promote the crosslinking reaction between epoxy groups and carboxyl groups or acid anhydride groups, tertiary amines such as pyridine, inquinoline, quinoline, N-N-dimethylcyclohexylamine, triethylamine, benzyldimethyl Amine, 1,8-diazo-bicyclo-undecene-7 and its amine salt should be added with a basic catalyst, tin octylate, BF, -monoethylamine, etc., based on the solid content of chlorinated polyolefin (+). 0
．． It can be added in a range of 0.05 wt % to 5° Ow t (but not limited to this).

In the case of acid anhydride groups, polyols such as ethylene glycol, trimethylolpropane, and polypropylene glycol may be used as reaction initiators. It is advisable to dry the coating film between room temperature and 150°C to obtain a cured coating film.

The solvent used in the coating composition according to the present invention is most preferably an aromatic solvent, and may also be partially mixed with other solvents such as an ester solvent, a ketone thread solvent, an alcohol thread solvent, etc. Inorganic pigments such as titanium oxide and talc and other organic pigments can also be used.

The present invention is characterized by crosslinking using a chlorinated polyolefin (Ink) obtained by modifying a polyolefin with a carboxyl group or a 9- or acid anhydride group and chlorinating it, or using a compound or resin (II) having an epoxy group. The object of the present invention is to obtain a coating film that has strong adhesion to polypropylene resin, which has conventionally been difficult to coat with a coating system, and has excellent other physical properties as well.

The coating composition according to the present invention is applied to the surface of a sheet or molded article made of polypropylene resin, air-dried at room temperature, and then dried at a temperature between room temperature and 150°C to obtain a one-coat finished coating. The resulting coating film has good appearance, solvent resistance,
Excellent water resistance, chemical resistance, bending resistance, impact resistance, etc.
In addition, it has much better adhesion to the substrate than other one-coat finish coatings used for similar purposes.
It can be applied not only to polypropylene resins but also to other base materials such as plastics, wood, and concrete.

The coating composition according to the present invention can also be used as an undercoat for polypropylene resin. At this time, the top coat used is an existing paint, such as urethane paint,
Epoxy resin paints, alkyd resin paints, etc. are suitable, and compared to paint films using conventional primer materials, they have better gasoline resistance, moisture resistance, water resistance, chemical resistance, bending resistance, and resistance. It has excellent impact resistance and exhibits strong adhesion to both base materials and top coats.

Next, the present invention will be specifically explained using Examples, but the present invention is not limited thereto.

Example-1 500 tons of isotactic polypropylene with a melt viscosity of about 2600 cps at 180°C was placed in a Mitsuro flask equipped with a stirrer, a dropping funnel, and a cooling pipe for refluxing the monomer, and the temperature was kept constant at 180°C. completely melted in an oil bath kept at . After replacing the inside of the flask with nitrogen for about 10 minutes, add maleic anhydride 2 while stirring with keyaki.
01 was added over a period of about 5 minutes, and then 29 klO- of g-tert-butyl peroxide was dissolved in hebutane and added through a dropping funnel over a period of about 30 minutes. At this time, the inside of the system was maintained at 180°C, and after continuing the reaction for about 1 hour,
Unreacted maleic anhydride was removed over about 30 minutes while reducing the pressure inside the flask with an aspirator. The saponification number of this product was 26. Next, this product was charged into a glass-lined reaction vessel, 5 tons of carbon tetrachloride was added, and after sufficiently melting at 110°C under a pressure of 2 K9/i, chlorination was carried out while irradiating with ultraviolet light. degree is 24w
Gaseous chlorine was blown from the bottom of the reaction vessel until the concentration reached t%.

After the reaction, carbon tetrachloride as a solvent was distilled off using an evaporator and replaced with toluene to obtain a 20 wt % toluene solution of chlorinated polypropylene modified with maleic anhydride.

Example-2 500 g of isotactic polypropylene used in Example-1, 30 g of maleic anhydride, and tert-
A maleic anhydride-modified polypropylene having a saponification value of 37 was obtained using Butyl Peroxide 21 in the same manner as in Example-1. Next, a chlorination reaction was carried out according to Example 1 to obtain a 20 wt % toluene solution of maleic anhydride-modified polypropylene with 1124 wt % chlorination.

Example-3 Isotactic polypropylene 500v used in Example-1, anhydrous maleic H4ot and G-tert-
Maleic anhydride and di-tert-butyl peroxide were simultaneously added sequentially over about 30 minutes using 3 liters of butyl peroxide. Other than that, the same method as in Example-1 was carried out. The saponification value of the maleic anhydride-modified polypropylene at this time was 49. Next, a chlorination reaction was carried out according to Example-1, and the degree of chlorination was 20 W t% of the maleic anhydride-modified chlorinated polypropylene with 5 wt% of chlorination.
A toluene solution was obtained.

Example-4 Melt viscosity at 180°C is about 5000 cps,
Ethylene-propylene copolymer 5001 with an ethylene content of 4.2 wt% and maleic anhydride 30? and Kid were simultaneously added for about 30 minutes. Other than that, the same method as in Example-1 was carried out. The saponification value of the maleic anhydride-modified ethylene-propylene copolymer at this time was 32. Next, a chlorination reaction was carried out according to Example 1, and anhydrous polymer 13-2 of leic acid modified chlorinated ethylene-propylene copolymer with a degree of chlorination of 24 wt% was
9wt%) toluene solution was obtained.

Example-5 35 (l) of the chlorinated product (20 wtqb toluene solution) obtained in Example-2 was mixed with 30 f'i of titanium oxide, and after dispersing the pigment in a sand mill for 1 hour, it was mixed with a condensate of bisphenol A and epichlorohydrin. Epoxy equivalent is 184-1
A 10 wt % xylene solution of amine catalyst U-Cat-8A-Nll 02 (manufactured by San Abbott Co., Ltd.) was added as a reaction accelerator. The mixture was diluted with an aromatic solvent to an appropriate viscosity and spray-painted onto a polypropylene plate (2 x 50 x 80 cm) whose surface had been washed with toluene. Allow to air dry at room temperature for approximately 15 minutes.

Example-6 Chlorinated product obtained in Example-2 (20 wt% toluene solution)
35 (l) and titanium oxide 309, completely dispersed the pigment in a sand mill for 1 hour, and then mixed with sorbitol polyglycidyl ether, an epoxy resin with an epoxy equivalent of 170, Bunacol EX-61,1 (manufactured by Nagase Sangyo Co., Ltd.). )1
07 Total ethyl acetate was mixed with 20 ml of ethyl acetate, and U-Cat 5A-N [Ll
Add all 72 of the 10 wt% xylene solution of 02, Example-5
A test plate was prepared in the same manner as (-1 coating test was conducted).

The results are shown in Table 1.

Example-7 The chlorinated product (2Qwt%)/renin solution obtained in Example-3 was mixed with titanium oxide 307 and the pigment was completely dispersed in a sand mill for 1 hour. Chitunnox CX-221 (manufactured by Chisso Corporation) 10.4r having an epoxy equivalent of 131 to 145 was blended with U-Cat 5A-N[Ll as a reaction accelerator.
02 in xylene was added, diluted to an appropriate viscosity with an aromatic solvent, and spray-painted on a polypropylene plate (2 x 50 x 80 mm) whose surface had been completely washed with toluene. After drying at room temperature for about 30 minutes, forced drying at 80° C. for 30 minutes, and standing at room temperature for 7 days, the coating film was tested. The results are shown in Table-1.

Example-8 Chlorinated compound (20 wt%) renin solution obtained in Example-4)
35 (l) and titanium oxide 302, and after completely dispersing the pigment in a sand mill for 1 hour, use diglycerol polyglycidyl ether as an epoxy resin with an epoxy equivalent of 155, Bunacol EX-421 (manufactured by Nagase Sangyo Co., Ltd.)
7.8S”i dissolved in ethyl acetate 202 was blended, and 1 of U-CatSA-Nα102 was added as a reaction accelerator.
A 0wt xylene solution of 1k7r was added, diluted to an appropriate viscosity with an aromatic solvent, and spray-painted on a polypropylene plate (2 x 50 x 80wn) whose surface had been washed with toluene. After air drying at room temperature for about 15 minutes, force drying at 120°C for 30 minutes, further air drying at room temperature for 7 days, and then drying at 120°C for 30 minutes.
After being force-dried for 7 minutes and left at room temperature for 7 days, the coating film was tested. The results are shown in Table 1.

Comparative Example-1 Chlorinated product obtained in Example-2 (20% toluene solution) 35
07 and titanium oxide 302, dispersed the pigment in a sand mill for 1 hour, diluted with an aromatic solvent to an appropriate viscosity, washed the surface with toluene, and prepared a polypropylene plate (
2x50x80mm) was spray painted.

After air drying at room temperature for about 15 minutes, forced drying at 130° C. for 30 minutes, and after standing at room temperature for 7 days, the coating film was tested. The results are shown in Table-1.

Comparative Example-2 Super Chron 803L (manufactured by Sanyo Kokusaku Valve Co., Ltd.,
20W of chlorinated polypropylene (degree of chlorination 26wt%)
Mix tqb toluene solution 3502 and titanium oxide 307, disperse the pigment in a sand mill for 1 hour, and then add U-Ca as a reaction accelerator.
Add a 10wt% xylene solution of tSA-N[L 102 to 71%, dilute with an aromatic solvent to an appropriate viscosity,
Polypropylene plate whose surface was cleaned with toluene (2 x 5
0x80m) was spray painted. After air drying at room temperature for about 15 minutes, forced drying at 130° C. for 30 minutes, and air drying at room temperature for an additional 7 days, the coating film was tested. Full results table-1
Shown below.

17-18- Test method Adhesion: Make 100 goblets on the painted surface that reach the substrate at 1-spacing intervals, stick cellophane adhesive tape on top of it, and peel it off in a 180° direction to remove the remaining goblets. I looked up the numbers.

Human gasoline resistance: Y latch that reaches the substrate on the painted surface (x mark)
was immersed in regular gasoline at 25°C for 2 hours, and the state of the coating was examined.

Flexing resistance: The condition of the coating film was examined by bending it by 180° using a φ inch mandrel.

Impact resistance: Using a DuPont impact tester, using a φ inch load of 500ft for the striking core, and dropping from 501M when hitting the surface,
In the case of lining, it was dropped from 25 crn.

Water resistance: The condition of the coating film was examined by immersing it in hot water at 50°C for 240 hours.

Humidity resistance: 240℃ in an atmosphere with relative humidity of 98% or more at 50℃
After leaving it for a while, the condition of the coating film was examined.

Example-9 Chlorinated product obtained in Example-1 (20 wt%) toluene solution)
200f, titanium oxide 4g, carbon black 70.1
? and Epicor) 828 1.6r were mixed, the pigment was dispersed in a sand mill for 1 hour, diluted with an aromatic solvent, and washed with toluene on a polypropylene plate (
2x50x80m+) was spray coated to a film thickness of 5 to 10μ. After a few minutes, a two-component urethane paint (manufactured by Nippon Oil & Fats Co., Ltd.) was spray-painted to a film thickness of 30 to 40μ, dried in hot air with room water for 15 minutes, then force-dried at 80°C for 30 minutes, and then dried for 24 minutes. After standing at room temperature for an hour, the coating film was tested. The resulting coating film had excellent gasoline resistance, bending resistance, impact resistance, moisture resistance, water resistance, etc., and also had very good adhesion.

Procedural official document (spontaneous) November 19, 1980 Director General of the Patent Office Wakakara Kefuro Jj (Q 2, Name of invention Composition for polypropylene resin 3, Relationship with the amended person case Patent application Address: 1-4-5 Marunouchi, Chiyoda-ku, Tokyo
Name (234) Sanyo Kokusaku Valve Co., Ltd. 4, Agent address: 16 Kanda Kita Jorimono-cho, Chiyoda-ku, Tokyo
101 Ei Building 3rd Floor 5, Detailed Explanation of the Invention Section 6 of the Specification Subject to Amendment, Contents of the Amendment As shown in the attached document, Contents of the Amendment (1) Page 16, lines 14-15 of the specification [further 7 days at room temperature After air drying at 120℃ for 30 minutes,
Delete certain.

(2) On page 20, line 4 of the statement box. [Corrected 70.1gJ to ro, 1gJ.

Claims (1)

[Claims] (1) A compound or resin having an epoxy group on a Boliole with a saponification value of 6 to 60 modified with one or more compounds selected from the group consisting of unsaturated polycarboxylic acids or their acid anhydrides. (II)'e A coating composition for a polypropylene resin, characterized in that the main constituent is ammonium. 1.00:
0.5 to 50, the coating composition for polypropylene resin according to claim (1).