JPH0159905B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a polyolefin laminate molded product which is composed of a polyolefin molded product base layer and a painted film layer, and which has excellent adhesion of the painted film and excellent impact resistance. In general, molded bodies of polyolefins such as polyethylene and polypropylene have various advantages such as being not only lighter than metal products and glass products, but also cheaper and easier to mold. It is widely used in place of these materials in household electrical appliances, daily necessities, and many other fields. However, these polyolefin molded bodies have a disadvantage in that they are inferior in surface hardness and impact resistance compared to metals, glass, etc., and are susceptible to scratching and friction, so that they are easily scratched on the surface. For example, the use of these molded bodies is limited due to their shortcomings in impact resistance and surface properties, such as their susceptibility to damage due to contact, collision, scratching, etc. during part installation or transportation work, or during product use. is severely limited. In order to improve the surface properties such as surface hardness, abrasion resistance, and scratch resistance of these polyolefin molded products, as well as their appearance, a method of coating the surface of the polyolefin molded product to form a paint film is widely used. However, even if a polyolefin such as polyethylene or polypropylene is directly coated, the adhesion between the base polyolefin layer and the painted film is extremely poor, so a laminate molded product that can withstand practical use cannot be obtained. In order to form a laminated molded product in which the base surface of these polyolefin molded products is coated with a paint film with good adhesion, a method is adopted in which the surface of the polyolefin is treated with various primers and then painted. However, even though the surface properties of the polyolefin laminate obtained by this method are improved, the impact resistance still remains unimproved, and it is used in fields that require impact resistance such as automobile parts such as bumpers and parts for electrical appliances. There were drawbacks such as the insufficiency of the method for application, the complicated painting process, and as a result, the manufacturing cost of the polyolefin laminate molded product. On the other hand, attempts have also been made to coat the substrate surface of a polyolefin molded article without subjecting it to the above-mentioned primer treatment to obtain a polyolefin laminate with improved adhesion, surface properties, and impact resistance. For example, a method of forming a polyolefin laminate molded product having a coating film by using a composition in which polyolefin is blended with an inorganic filler and an unmodified rubber as a polyolefin molded product base and applying a coating to the surface of the polyolefin molded product base is known. Although the impact resistance and surface properties of the laminated molded product are improved, the effect of improving the adhesion of the paint film is small, and as mentioned above, it is still insufficient for use in applications such as automobile parts. It was hot. The present inventors investigated the development of a polyolefin laminate molded product with improved impact resistance, paint film adhesion, and surface properties by painting the base surface of the polyolefin molded product without applying a primer treatment. However, a polyolefin laminate molded product has achieved the above object by forming a painted film on the surface of a molded product base layer made of a specific polyolefin composition containing a highly crystalline polyolefin and a low-crystalline modified polyolefin. The present invention was achieved based on the discovery that the following can be obtained. To summarize the present invention, the present invention provides a highly crystalline polyolefin (a) and a low crystalline modified polyolefin.
A polyolefin laminate molded product comprising a molded product base layer [A] and a painted film layer [B] made of a polyolefin composition containing (b), the modified polyolefin (b) constituting the polyolefin composition. The blending ratio is 1 to 100% by weight of the highly crystalline polyolefin (a).
100 parts by weight of the low-crystalline modified polyolefin (b) contains 100 parts by weight of an ethylene/α-olefin copolymer based on unsaturated carboxylic acid or its acid anhydride component unit (c); is graft copolymerized in the range of 0.01 to 10 parts by weight, and its intrinsic viscosity [η] is
of the base ethylene/α-olefin copolymer constituting the low crystallinity modified polyolefin; A polyolefin laminate molded product, characterized in that the ethylene content is in the range of 35 to 93 mol%.
The main points are as follows. In the laminate molded article of the present invention, the highly crystalline polyolefin (a) in the polyolefin composition constituting the base layer [A] usually has a crystallinity of 85 to 50%, preferably 80% as measured by X-ray diffraction. It is in the range of 60% to 60%. Specifically, polyolefins include ethylene, propylene, 1-butene,
1-hexene, 4-methyl-1-pentene, 1-
A homopolymer of α-olefin such as octene or 1-decene, a copolymer consisting of a mixture of two or more of the α-olefins, or a copolymer containing the α-olefin as a main component and a lower polymer such as vinyl acetate or vinyl propionate. A small amount of other ingredients such as aliphatic vinyl carboxylates, methyl acrylate, metal salts of acrylic acid, methyl methacrylate, acrylic carboxylic acid esters such as metal salts of methacrylic acid, and salts of acrylic carboxylic acids (for example, 30 (mol% or less)
Examples include copolymers and the like.
The intrinsic viscosity [η] of these polyolefins measured in decalin solvent is usually 0.5 to 5.0 dl/g,
Preferably it is in the range of 1.0 to 4.0 dl/g. In the laminate molded product of the present invention, the low-crystalline modified polyolefin (b) constituting the base layer [A] made of a polyolefin composition is obtained by graft copolymerizing an unsaturated carboxylic acid or its acid anhydride component unit (c). It is a low crystallinity modified ethylene/α-olefin copolymer. The grafting ratio of the unsaturated carboxylic acid or its acid anhydride component unit (c) of the low-crystalline modified polyolefin (b) is 0.01 to 10 parts by weight based on 100 parts by weight of the base ethylene/α-olefin copolymer described below. must be in the range of 0.1
The amount is preferably in the range of 7 to 7 parts by weight. The grafting ratio of the unsaturated carboxylic acid or its acid anhydride component unit of the low crystallinity modified polyolefin is
If the amount is less than 0.01 part by weight, the adhesion of the paint film of the polyolefin laminate molded product will decrease, and if it is more than 10 parts by weight, the degree of crosslinking of the low-crystalline modified polyolefin will increase, making it difficult to sufficiently finely disperse the polyolefin laminate. The impact strength of the molded body begins to decrease. Furthermore, the intrinsic viscosity [η] of the low-crystalline modified polyolefin (b) measured in a decalin solvent at 135°C must be in the range of 0.5 to 5.0 dl/g, and more preferably 0.7 to 4.0 dl/g.
It is preferable that it is in the range of g. When the intrinsic viscosity [η] of the low-crystalline modified polyolefin is greater than 5.0 dl/g, the melt viscosity becomes extremely large, making fine dispersion difficult, reducing the adhesion of the paint film of the polyolefin laminate, and The impact strength of the polyolefin laminate molded product begins to decrease, and when it becomes less than 0.5 dl/g, the impact strength of the polyolefin laminate molded product also decreases. The crystallinity of the low crystallinity modified polyolefin (b) measured by X-ray diffraction must be in the range of 0 to 50%, and more preferably in the range of 0 to 40%.
% range is preferable. When the degree of crystallinity of the low-crystalline modified polyolefin exceeds 50%, the impact resistance of the polyolefin laminate molded product decreases, and the adhesion of the coating film also decreases. Furthermore, the molecular weight distribution (w/n) of the low crystallinity modified polyolefin (b) is usually in the range of 1 to 15, preferably 1 to 10, and its density is in the range of 0.83 to 10.
0.94 g/cm ³ , preferably in the range of 0.84 to 0.92 g/cm ³ . The unsaturated carboxylic acid or acid anhydride component unit (c) of the graft monomer component constituting the low-crystalline modified polyolefin includes maleic acid, fumaric acid, itaconic acid, citraconic acid, tetrahydrophthalic acid, and methyltetrahydrophthalic acid. , endocys-bicyclo[2,2,1]hept-5-ene-2,3-dicarboxylic acid (nadic acid), methyl-endocys-bicyclo[2,2,1]pept-5-ene-2,3- Dicarboxylic acid (methylnadic acid), maleic anhydride, citraconic anhydride,
Itaconic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, endocis-bicyclo[2,2,1]hept-5-ene-2,3
-dicarboxylic anhydride, methyl-endocys-bicyclo[2,2,1]hept-5-ene-2,3
- dicarboxylic acid anhydride, etc., and a mixture of two or more of these components may be used. Among these unsaturated carboxylic acids or acid anhydride component units, unsaturated dicarboxylic acids or acid anhydrides are preferred, and maleic acid, maleic anhydride, nadic acid, or nadic anhydride are particularly preferred. . The base ethylene/α-olefin copolymer constituting the low-crystalline modified polyolefin is a low-crystalline or amorphous ethylene/α-olefin copolymer with an ethylene content of 35 to 93 mol%. The content is preferably within a range of 40 to 93 mol%. Even if the ethylene content of the ethylene copolymer is greater than 93 mol% or less than 35 mol%,
The ethylene/α-olefin copolymer becomes highly crystalline, and the modified ethylene/α-olefin copolymer obtained from the copolymer becomes highly crystalline.
The α-olefin copolymer also becomes highly crystalline, and as a result, the effect of improving the impact resistance of the polyolefin laminate is reduced, and the adhesion of the paint film is reduced. The intrinsic viscosity [η] of the ethylene/α-olefin copolymer measured in a decalin solvent is usually 0.5 to 5 dl/g, preferably 0.7.
to 4.0 dl/g, and the density is usually 0.83
from 0.94 g/cm ³ , preferably from 0.84 to 0.92
g/cm ³ range. Furthermore, the ethylene α-
Olefin copolymers are amorphous or have low crystallinity, and the degree of crystallinity measured by X-ray diffraction is usually 0.
In the range of 50% to 50%, preferably 0 to 40%
% range. The α-olefin component units constituting the ethylene/α-olefin copolymer include propylene, 1-butene, 1-hexene, 4-methyl-1
-Pentene, 1-decene, 1-hexadecene, 1
- Icosene, etc., and it is one kind or a mixture of two or more kinds thereof. The ethylene/α-olefin copolymer is usually a copolymer of an ethylene component and an α-olefin, but in some cases it may contain a trace amount, for example, 0.5 mol% or less, of a diene component. can not use. To produce the low crystallinity modified ethylene/α-olefin copolymer by graft copolymerizing the graft monomer selected from the unsaturated carboxylic acid or its acid anhydride to the ethylene/α-olefin copolymer, conventional methods are used. Various methods known from can be employed. For example, there is a method of melting an ethylene/α-olefin copolymer and adding a graft monomer to carry out graft copolymerization, or a method of dissolving the ethylene/α-olefin copolymer and adding a graft monomer to carry out graft copolymerization. In any case, in order to efficiently graft copolymerize the graft monomer, it is preferable to carry out the reaction in the presence of a radical initiator. Grafting reactions are usually 60 or
It is carried out at a temperature of 350℃. The proportion of the radical initiator used is usually in the range of 0.01 to 20 parts by weight per 100 parts by weight of the ethylene/α-olefin copolymer. As a radical initiator, organic peroxide,
Organic peresters such as benzoyl peroxide, dichlorobenzoyl peroxide, dicumyl peroxide, di-tert-butyl peroxide,
2,5-dimethyl-2,5-di(peroxybenzoate)hexyne-3,1,4-bis(tert-
butylperoxoisopropyl)benzene, lauroylperoxide, tert-butylperacetate, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-di( tert-butyl peroxy)hexane, tert-butyl perbenzoate, tert-butyl perphenyl acetate, tert-butyl per-
Examples include sec-octoate, tert-butyl perpivalate, cumyl perpivalate and tert-butyl perdiethyl acetate, and other azo compounds such as azobisisobutyronitrile, dimethylazoisobutyrate and the like. In the laminate molded product of the present invention, the blending ratio of the low crystallinity modified polyolefin (b) in the polyolefin composition constituting the base layer [A] is 1 part by weight per 100 parts by weight of the high crystallinity polyolefin (a). or 100
The amount is preferably in the range of 5 to 90 parts by weight.
If the blending ratio of the low-crystalline modified polyolefin (b) to 100 parts by weight of the high-crystalline polyolefin (a) is less than 1 part by weight, the impact resistance of the polyolefin laminate will decrease, and the paint coating will deteriorate. Adhesion will decrease, and if the amount exceeds 100 parts by weight, the rigidity and heat resistance of the polyolefin laminate will decrease. A conventional method can be used to prepare a composition comprising the highly crystalline polyolefin (a) and the low crystalline modified polyolefin (b). For example, a method may be employed in which powders or pellets of both components are dry blended and then melted and kneaded, or a premixing method in which a portion of both components is preliminarily melted and mixed. Further, if necessary, a method of blending a stabilizer, a plasticizer, a lubricant, an inorganic filler, etc. and kneading the mixture using a mixing roll, a Banbury mixer, an extruder, etc. is adopted. In the laminate molded product of the present invention, the molded product base layer [A] made of the polyolefin composition may be in any shape, such as a film shape, a sheet shape,
The molded product may be a molded product having a plate shape, a curved surface, an uneven surface, or any other shape. In the polyolefin laminate molded product of the present invention,
The paint film layer [B] is applied in close contact with at least one side of the base layer [A], and is applied directly to the surface of the base layer without intervening an intermediate adhesive such as a primer layer. It is a layered product. Examples of the paint film include paint films formed from various types of paint compositions and clear coat films formed from crosslinked curable resin compositions. More specifically, paint films formed from oil-based paints such as drying oil paints, boiled oil paints, and oil-based varnishes, and alkyd resin paints such as alkyd resin paints, oil-modified alkyd resin paints, and styrenated alkyd resin paints. paint films formed from curable resin paints such as amino resin paints, epoxy resin paints, curable acrylic resin paints, and phenol resin paints; reaction-curable resin paints such as unsaturated polyester resin paints and polyurethane paints. An example of this is a painted film formed from. These paint films are 1
In some cases, it is a single layer coating consisting only of seeds, but 2
It may also be a multilayer coating consisting of more than one type of paint coating. The thickness of the paint film is arbitrary, but usually ranges from 1 to 500 microns, preferably from 5 to 100 microns. In the polyolefin laminate molded product of the present invention,
The painted film layer [B] is formed on at least one side of the molded body base layer [A] made of the polyolefin composition.
As a method for forming the polyolefin composition, a method is adopted in which the coating composition or the crosslinked curable resin composition is applied to the surface of the molded body base layer made of the polyolefin composition by a conventional method, and then dried and cured. can do. As a coating method, conventionally known methods such as a brush coating method, a dipping method, a spray method, a bar code method, a roll coater method, a spin coater method, and a gel coater method can be employed. In addition, when performing the above-mentioned coating treatment on the substrate surface of the molded article made of the polyolefin composition,
The surface of the molded body is cleaned in advance with various solvents,
Cleaning with aqueous alkaline solution, cleaning with surfactant, ultrasonic cleaning, electrolytic cleaning, blasting treatment, sandblasting treatment, etching treatment with acid or alkali, flame treatment, corona discharge treatment, arc discharge treatment, glow discharge treatment, plasma discharge It is also possible to perform various surface treatments, such as surface treatment. Next, the polyolefin laminate molded product of the present invention will be specifically explained using Examples. The laminate molded bodies obtained in Examples and Comparative Examples were evaluated by the following method. (1) Adhesion The test was conducted according to the cross-cut test in JIS K 5400-1979. The goban eyes were made with 1mm square. Judgment is based on how many of the 100 pieces are glued together. (2) Water resistance After immersing the test piece in pure water at 40°C for 240 hours, changes in the appearance of the outer coating layer were visually observed to evaluate adhesion. (3) Peeling strength A peeling test was conducted on a 10 mm wide paint film at a rate of 50 mm/min to measure the peeling strength of the paint film. (4) Flexural modulus FM according to ASTM D-790-80
(Kg/cm ² ) and bending yield strength FS (Kg/cm ² ) were measured. (5) Drop impact strength Drop impact strength (FD) is measured by dropping a weight of a certain shape from a certain height onto a test piece placed horizontally at -30°C, changing the weight of the weight, and applying a certain number of magazines. This is the impact strength (Kg・cm) calculated from the energy required for 50% of the specimen to break. Examples 1 to 2, Comparative Example 1 Isometric polypropylene ([η]: 2.95 dl/
g, density 0.91 g/cm ³ , crystallinity 68%) and ethylene-propylene copolymer (ethylene content 80 mol%, [η] 2.05 dl/g, density 0.88 g/cm ³ , crystallinity 15%) ) 100 parts by weight of maleic anhydride (MAH)
maleic anhydride graft-modified ethylene-propylene copolymer ([η] 1.99 dl/g, density 0.87 g/cm ³ , crystallinity 14)
%) in the proportions shown in Table 1 using a blender to prepare a dry blend product. This dry blend composition was supplied to a LID28, 25mmφ extruder (full flight type screw) at 230℃,
The mixture was kneaded and granulated by passing it once at 60 rpm. Subsequently, an injection square plate (130 x 130 x 2 mm) was obtained using an injection molding machine (IS-50, manufactured by Toshiba). Urethane paint (Nippon Bike Chemical Co., Ltd., product name R257/
R263) was spray applied at room temperature using the air atomization method.
It was left to dry at room temperature for about 5 minutes, then placed in an air oven and baked at 80°C for 30 minutes. Subsequently, evaluation was performed using the method described above. The evaluation results are shown in Table 1. Examples 3 to 4 As a low crystallinity modified polyolefin, ethylene/1-butene copolymer (ethylene content 90 mol%, [η] 1.55 dl/g, density 0.88 g/cm ³ , crystallinity 18%) 100 Maleic anhydride graft modified ethylene/1-butene copolymer ([η] 1.48 dl/
The same procedure as in Example ¹ was carried out except that the following materials were mixed in the proportions shown in Table 1. Example 5 Ethylene-propylene copolymer (Example 1)
A maleic anhydride graft-modified ethylene-propylene copolymer ([η] 1.81 dl/g, density 0.87 g/cm ³ , crystallinity 15%) was used by graft copolymerizing 3.5 parts by weight of maleic anhydride to 100 parts by weight. The same procedure as in Example 1 was carried out except for the following. Example 6 As a low-crystalline modified polyolefin, 100 parts by weight of ethylene-propylene copolymer (ethylene content 45 mol%, [η] 2.03 dl/g, density 0.86 dl/cm ³ , crystallinity 5%) was added anhydrous. Maleic anhydride graft-modified ethylene/propylene copolymer with 6.5 parts by weight of maleic acid ([η] 0.83 dl/
Example 1 was carried out in the same manner as in Example 1, except that a material (density: 0.89 g/cm ³ , crystallinity: 4%) was used. Example 7 As a low-crystalline modified polyolefin, anhydrous maleic was added to 100 parts by weight of ethylene-propylene copolymer (ethylene content 90 mol%, [η] 1.58 dl/g, density 0.90 g/cm ³ , crystallinity 45%). Maleic anhydride graft-modified ethylene/propylene copolymer ([η] 1.52 dl/
Example 1 was carried out in the same manner as in Example 1, except that a material (density: 0.90 g/cm ³ , crystallinity: 43%) was used. Example 8 Ethylene-propylene copolymer (Example 1)
Nadzic anhydride-modified ethylene/propylene copolymer ([η] 1.31 dl/g, density 0.87 g/
The same procedure as in Example ¹ was carried out except that the crystallinity (crystallinity: 14%) was used. Example 9 Propylene-ethylene block copolymer (ethylene content
15.3 mol%, [η] 3.51 dl/g, density 0.91 g/cm ³ ,
The same procedure as in Example 1 was carried out except that a crystallinity of 64% was used. Example 10 The same procedure as in Example 1 was carried out except that polyethylene (1-butene content 3 mol%, [η] 2.12 dl/g, density 0.96 g/cm ³ , crystallinity 80%) was used as the highly crystalline polyolefin. Ivy. Example 11 Same as Example 1 except that poly4-methyl-1-pentene (TPX, [η] 2.32 dl/g, density 0.84 g/cm ³ , crystallinity 73%) was used as the highly crystalline polyolefin. I went in the same way. Example 12 The injection molded square plate obtained in Example 1 was
- The same procedure as in Example 1 was carried out except that the sample was steam washed with trichloroethane for 30 seconds. Example 13 The same procedure as in Example 1 was performed except that the injection molded square plate obtained in Example 1 was subjected to low-temperature plasma treatment (O ₂ plasma, 50 W, 30 sec, 1.5 torr). Example 14 In Example 1, acrylic paint (NOF)
Made by KK, metallic purple for polypropylene/
The same procedure as in Example 1 was carried out except that Hiurethane No. 5000 and Candy Wine Red for polypropylene were used. Example 15 Melamine alkyd paint (Kansai Paint KK
The same procedure as in Example 1 was carried out except that Amirac No. 3 White (manufactured by Amirac Co., Ltd.) was used. Comparative Example 2 Unmodified ethylene/propylene copolymer (ethylene content 80 mol) as low crystalline polyolefin
%, [η] 2.05 dl/g, density 0.88 g/cm ³ , crystallinity 15%). Comparative Example 3 Low crystalline polyolefin used in ethylene-propylene copolymer (Example 1)
A maleic anhydride-grafted modified ethylene-propylene copolymer ([η] 1.82 dl/g, density 0.90 g/cm ³ , crystallinity 15%) was used by graft copolymerizing 11 parts by weight of maleic anhydride to 100 parts by weight. The same procedure as in Example 1 was carried out except for the following. Comparative Example 4 Ethylene-propylene copolymer (ethylene content 98 mol%, [η] 2.61 dl/g, density 0.96 g/cm ³ ,
0.7 maleic anhydride in 100 parts by weight (crystallinity 75%)
Part by weight graft copolymerized maleic anhydride graft modified ethylene/propylene copolymer ([η]
The same procedure as in Example 1 was conducted except that 2.54 dl/g, density 0.95 g/cm ³ , and crystallinity 73% were used. Comparative Example 5 Instead of low crystallinity modified polyolefin, ethylene/vinyl acid copolymer (manufactured by Mitsui Polychemical KK,
The same procedure as in Example 1 was carried out except that EVAFLEX, 40X) was used. Comparative Example 6 The same procedure as in Example 1 was carried out except that the same injection molded square plate made of isotactic PP alone as used in Example 1 was used. Comparative Example 7 The same procedure as in Example 1 was carried out except that the same injection molded square plate made of polyethylene used in Example 10 was used.

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Claims (1)

[Scope of Claims] 1 Polyolefin laminate molding consisting of a molded body base layer [A] made of a polyolefin composition containing a highly crystalline polyolefin (a) and a low crystalline modified polyolefin (b) and a painted film layer [B] [] The blending ratio of the modified polyolefin (b) constituting the polyolefin composition is 1 to 1 to 100 parts by weight of the highly crystalline polyolefin (a).
100 parts by weight of the low-crystalline modified polyolefin (b) contains 100 parts by weight of an ethylene/α-olefin copolymer based on unsaturated carboxylic acid or its acid anhydride component unit (c); is graft copolymerized in the range of 0.01 to 10 parts by weight, and its intrinsic viscosity [η] is
of the base ethylene/α-olefin copolymer constituting the low crystallinity modified polyolefin; A polyolefin laminate molded product characterized by having an ethylene content in the range of 35 to 93 mol%.