JPH0124407B2 - - Google Patents

Description

[Detailed description of the invention]

[]Object of the Invention The present invention relates to an olefinic polymer composition having excellent paintability, printability, and adhesiveness. More specifically, (A) crystalline propylene polymer, (B) styrene polymer with a molecular weight of 22,000 to 400,000, (C) ethylene-vinyl acetate copolymer and/or ethylene-acrylic acid ester copolymer. This invention relates to an olefinic polymer composition comprising a polymer and (D) an ethylene polymer, and its purpose is to provide an olefinic polymer composition with improved paintability, printability, and adhesion. be. [] Background of the Invention As is well known, olefin polymers (ethylene polymers, propylene polymers, and copolymers with other olefins containing ethylene or propylene as a main component) are widely produced industrially and are widely used for general purpose use. It is used as a resin in many ways. however,
Olefin polymers are so-called non-polar, chemically extremely inert polymeric substances that do not have polar groups in their molecules. Furthermore, they are highly crystalline and have extremely low solubility in solvents, so they can be used for painting, printing, etc. Or when used in fields such as adhesion, they are very scarce. In order to solve these problems, various methods such as those described below have been proposed for quite some time. (a) A method in which an olefin polymer or a molded product thereof is surface-treated from the outside and modified by a physical or chemical method [hereinafter referred to as the "modification method"]. (b) A method of adding other polymeric substances or additives to the olefin polymer [hereinafter referred to as the "addition method"]. Below, these methods will be explained in more detail and problems will be described. (1) Modification method This method includes ``flame treatment method, ozone treatment method, corona discharge treatment method, plasma treatment method, and ultraviolet or electron beam irradiation treatment method [hereinafter referred to as ``denaturation method (a)''] and ``chromium A method of treatment using an acid mixture and a mineral acid such as concentrated sulfuric acid, and a chemical treatment method such as grafting of an olefin polymer with a compound containing a polar group in the presence or absence of a crosslinking agent. Hereinafter referred to as "denaturation method (b)"]. By these modification methods, chemically active sites rich in polar groups are provided on the surface of the olefin polymer or its molded product, and the surface is physically roughened. As a result, paintability, printability,
It is thought that the effect of improved adhesion can be obtained. However, in order to carry out this modification method (a), the shape of the molded object to be treated must be significantly limited, and furthermore, the treatment effect not only changes significantly over time due to leaving it after treatment, but also In many cases, the degree of activation is not always sufficient. Moreover, it has disadvantages such as being economically disadvantageous because it requires various expensive processing equipment. In addition, among the modification methods (b), in the treatment method using mineral acids, the chemicals used tend to become a source of pollution;
Complicated post-treatment steps such as neutralization, washing, and drying are required. Furthermore, chemical treatment methods such as grafting can also be used to coat monomers,
It requires careful consideration in the selection of a graft initiator, the atmosphere for grafting, etc., and also requires a long grafting reaction time, so it has disadvantages such as being unsuitable for continuous production. (2) Addition method This method includes ``a so-called resin blending method in which a rubber substance and/or a resin containing a polar group is added to the olefinic polymer'' [hereinafter referred to as ``addition method (a)'']; A method of adding additives such as fillers (for example, calcium carbonate, barium sulfate, talc, clay, wood flour)" [hereinafter referred to as "addition method (b)"]
can be given. In addition method (a), when adding a rubber substance to an olefin polymer, since the rubber substance is generally in the form of a lump, a continuous mixer ( For example, it is not only almost impossible to perform continuous kneading using an extruder, but also the mechanical properties of the resulting mixture, such as stiffness, hardness, and heat resistance, are significantly reduced. There are drawbacks. On the other hand, when a resin containing a polar group is added to an olefinic polymer, the compatibility between the resin and the olefinic polymer is generally poor, so the physical properties of the molded product of the resulting composition (for example, strength,
This has drawbacks such as not only a decrease in impact resistance (impact resistance) but also, in extreme cases, delamination. In addition, in the case of addition method (b), the flow characteristics of the resulting composition are reduced, which not only makes molding difficult, but even if a molded product is obtained, impact resistance and elongation may deteriorate. There are problems such as decreased mechanical properties and deterioration of appearance, etc., and disadvantages such as limited range of use. Based on these facts, some of the present inventors conducted various searches in order to obtain an olefin polymer composition that does not have these drawbacks and has excellent paintability, printability, and adhesiveness, and as a result, (A ) Polyolefin (olefin polymer) 100
Parts by weight, (B) 0.5 to 20.0 parts by weight of a styrenic polymer mainly composed of styrene with a molecular weight of 200,000 to 400,000, and (C) 3.0 to 40.0 parts by weight of methyl methacrylate ester. We have previously proposed a polyolefin composition consisting of 40% by weight ethylene-methacrylic ester copolymer, which does not have the above-mentioned drawbacks and has excellent paintability, printability, and adhesion. 165693). however,
The paintability, printability and adhesiveness of the composition are not necessarily satisfactory in practical use. [] Structure of the Invention Based on the above, the present inventors have conducted various searches in order to obtain an olefin polymer composition that does not have these drawbacks and has extremely excellent paintability, printability, and adhesiveness. (A) Melt flow index (according to JIS K-6758, measured at a temperature of 230°C and a load of 2.16 kg, hereinafter referred to as "MFI") is 0.01 ~
Crystalline propylene polymer with 100g/10min
100 parts by weight, (B) 0.5 to 20.0 parts by weight of a styrenic polymer mainly composed of styrene with a molecular weight of 22,000 to 400,000 (C) Ethylene-vinyl acetate copolymer with a vinyl acetate content of 5.0 to 50% by weight Ethylene-acrylic ester copolymer with a polymer and/or acrylic ester content of 5.0 to 40% by weight
3.0 to 28.0 parts by weight and (D) density of 0.900 to 0.975 g/ ^cm3 , and melt index (according to JIS K-6760, measured at a temperature of 190°C and a load of 2.16 kg,
(hereinafter referred to as "MI") is at least 0.1g/10
The inventors have discovered that 3.0 to 30.0 parts by weight of an ethylene-based polymer, which is a 3.0 to 30.0 parts by weight component, does not have the above-mentioned drawbacks and has excellent paintability, printability, and adhesion, and has thus arrived at the present invention. [] Effects of the Invention The composition obtained by the present invention not only has the above characteristics, but also exhibits the following effects (characteristics). (1) There is almost no deterioration in mechanical properties such as fluidity, rigidity, and elongation that olefin polymers have, and in particular, impact resistance is extremely excellent. (2) It has excellent moldability and can be kneaded continuously using a continuous kneading machine such as an extruder, so manufacturing costs can be reduced. (3) Since the olefin polymer has good compatibility with the styrene polymer and the ethylene-vinyl acetate copolymer or ethylene-acrylic acid ester copolymer, delamination of the molded product does not occur. (4) Unlike the modification method (a), no expensive processing equipment is required. (5) The resulting molded product not only has an excellent appearance but also has high gloss. (6) Mechanical strength (e.g., rigidity, impact resistance) is good. Since the olefin polymer composition obtained by the present invention exhibits the excellent effects (characteristics) mentioned above, it can be applied in a wide variety of applications by being painted or printed. Typical uses are shown below. (1) Auto parts such as bumpers, bumper corners and front grills (2) Motorcycle parts such as fenders, leg shields and side covers (3) Parts of home appliances such as audio equipment, televisions, electric fans and radio cassettes (4) Helmets ( 5) Containers (6) Furniture (7) Daily necessities (8) Building materials, etc. [] Specific description of the invention (A) Propylene polymer The propylene polymer used in the present invention is crystalline, and propylene Homopolymers and propylene and ethylene and/or α-olefins having 4 to 12 carbon atoms (for example, butene-1, hexene-1, 4-methylpentene-
1, a random or block copolymer with octene). Among these propylene-based polymers, the copolymerization ratio of ethylene and α-olefin in random and block copolymers is usually at most 25% by weight (preferably 20% by weight or less). Also, MFI is 0.01~100g/
10 minutes, preferably 0.01 to 50 g/10 minutes, particularly preferably 0.1 to 50 g/10 minutes. MFI
If less than 0.01 g/10 min of propylene polymer is used, it is difficult to knead the composition and obtain a uniform composition. On the other hand, even if a uniform composition is obtained, it may not be possible to produce molded articles. On the other hand, if a propylene polymer having an MFI of more than 100 g/10 minutes is used, the kneading properties and moldability are good, but on the other hand, a composition having excellent mechanical strength cannot be obtained. (B) Styrenic polymer The molecular weight of the styrenic polymer used in the present invention is 22,000 to 400,000,
22,000 to 350,000 is preferred, particularly 22,000 to 300,000 is preferred. If the molecular weight exceeds 400,000, the miscibility with the propylene polymer will be poor and it will be difficult to disperse during kneading. On the other hand, if the molecular weight is less than 22,000, the resulting composition will have poor impact resistance.
The styrenic polymer used in the present invention may be a styrene homopolymer or a copolymer of styrene and another monomer (copolymerization ratio is 40 mol% or less). Other monomers include monoolefins (at most 8 carbons), diolefins (at most 8 carbons) and (meth)acrylic esters (at most 8 carbons) and acrylonitrile. Examples include polar group-containing vinyl compounds. The styrenic polymers may be used alone or in combination of two or more. (C) Ethylene-vinyl acetate copolymer Furthermore, the content of vinyl acetate in the ethylene-vinyl acetate copolymer used in the present invention is 5 to 50% by weight, particularly preferably 10 to 40% by weight. It is not desirable to use an ethylene-vinyl acetate copolymer with a vinyl acetate content of 5% by weight or less because the modification effect will not be satisfactory. On the other hand, the content of vinyl acetate is 50
If more than % by weight of the ethylene-vinyl acetate copolymer is used, it is not preferable because it has poor compatibility with the propylene-based polymer, which not only deteriorates the physical properties of the composition but also causes delamination. (D) Ethylene-acrylic ester copolymer The content of acrylic ester in the ethylene-acrylic ester copolymer used in the present invention is 5 to 40% by weight, particularly 10 to 30% by weight. is desirable. It is not preferable to use an ethylene-acrylic ester copolymer with an acrylic ester content of 5% by weight or less, since the modification effect is not satisfactory. On the other hand, if an ethylene-acrylic ester copolymer with an acrylic ester content of 40% by weight or more is used, it will not only deteriorate the physical properties of the composition due to poor compatibility with the propylene polymer, but also cause layer peeling. This is undesirable because it causes The acrylic ester, which is a monomer of the copolymer, is obtained from acrylic acid and an alcohol having 1 to 8 carbon atoms. In carrying out the present invention, the ethylene-vinyl acetate copolymer and the ethylene-acrylic acid ester copolymer may be used alone or in combination of two or more. (E) Ethylene polymer Furthermore, the ethylene polymer used in the present invention is selected from ethylene homopolymers and copolymers of ethylene and α-olefin having at most 12 carbon atoms. Among the ethylene-based polymers, the copolymerization ratio of α-olefin in the copolymer of ethylene and α-olefin is generally at most 20% by weight (preferably 15% by weight or less). Further, typical examples of the α-olefin include propylene, butene-1, hexene-1,
Examples include 4-methylpentene-1 and octene-1. The density of this ethylene polymer is
0.900~0.975g/ ^cm3 , especially 0.900~0.970
g/cm ³ is preferred. Furthermore, MI is at least
0.1/10 minutes, preferably 0.1 to 50 g/10 minutes, particularly preferably 0.5 to 20 g/10 minutes. MI
If an ethylene polymer having a coating composition of less than 0.1 g/10 minutes is used, it will be difficult to obtain a uniform composition, and even if a molded product is obtained, the paintability and appearance of the molded product will be poor. The propylene-based polymer and ethylene-based polymer of the present invention are prepared by using a carrier-supported catalyst obtained by supporting a transition metal compound on a transition metal compound (e.g., a titanium-based compound or a carrier (e.g., a magnesium compound, a processed product thereof)). and an organometallic compound (for example, an organoaluminum compound) (so-called Ziegler catalyst), or a catalyst system obtained by supporting a chromium-containing compound (for example, chromium oxide) on a carrier (for example, silica). In addition, ethylene polymers, ethylene-vinyl acetate copolymers, and ethylene-acrylic ester copolymers can be obtained by homopolymerization using a radical initiator (for example, organic peroxide). These propylene polymers, ethylene polymers, ethylene-vinyl acetate copolymers and ethylene-acrylic ester copolymers are Both are industrially produced,
It is used in many ways. (E) Composition ratio The composition ratio of styrene polymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, and ethylene polymer to 100 parts by weight of the propylene polymer of the present invention is as follows: Coalescence is 0.5-20.0 parts by weight and 1.0
~20.0 parts by weight is desirable, and 1.0 to 15.0 parts by weight is particularly preferred. The composition ratio of styrene polymer to 100 parts by weight of propylene polymer is
If it is less than 0.5 parts by weight, there will be almost no modification effect. On the other hand, if the amount exceeds 20.0 parts by weight, physical properties such as impact resistance, elongation, and cold resistance of the resulting composition will deteriorate, and no effect of increasing the amount will be observed in terms of paintability, printability, and adhesion. In addition, the composition ratio of ethylene-vinyl acetate copolymer and/or ethylene-acrylic acid copolymer is 3.0
~28.0 parts by weight, preferably 5.0 to 28.0 parts by weight, particularly preferably 5.0 to 25.0 parts by weight.
If the composition ratio of the ethylene-vinyl acetate copolymer and/or ethylene-acrylic acid ester copolymer to 100 parts by weight of the propylene polymer is less than 3.0 parts by weight, there will be almost no modification effect. On the other hand, if it exceeds 28.0 parts by weight, it is not preferable because not only will there be no increase in weight, but the resulting composition will not have satisfactory rigidity, strength, and heat resistance. Further, the composition ratio of the ethylene polymer is 3.0 to 30.0 parts by weight, preferably 5.0 to 28.0 parts by weight, and particularly preferably 5.0 to 25.0 parts by weight. If the composition ratio of the ethylene polymer to 100 parts by weight of the propylene polymer is less than 3.0 parts by weight, there is almost no modification effect. on the other hand,
If the amount exceeds 30.0 parts by weight, no effect of increasing the amount will be observed on the paintability, printability and adhesiveness of the resulting composition. (G) Mixing method, molding method, use, etc. In producing the composition of the present invention, propylene polymer, styrene polymer, ethylene-
Vinyl acetate copolymer and/or ethylene-
Although it is possible to achieve the objective simply by mixing the acrylic ester copolymer and the ethylene polymer, it is possible to achieve the objective by simply mixing the acrylic acid ester copolymer and the ethylene polymer, but it is possible to achieve the purpose by mixing only the acrylic ester copolymer and the ethylene polymer. Other resins and rubbers can be added (up to 30% by weight based on the combined weight). In addition, if necessary, oxygen, light or heat stabilizers, flame retardants, fillers, reinforcing agents, processability modifiers, lubricants, antistatic agents and pigments commonly used in propylene polymers may be added. Of course, additives such as the following may be added. The composition may also be obtained by dry blending using a mixer such as a tumbler, ribbon blender, and Hensel mixer.
It is also possible to knead using a cross-type kneader (for example, Banbury mixer).
As described above, continuous kneading can also be carried out using a continuous mixer. Moreover, more uniform mixing can be achieved by using these methods in combination (for example, by dry blending and then continuously kneading). Since the obtained mixture (composition) does not essentially change the physical properties of the propylene polymer, injection molding, extrusion molding, and blow molding methods that are commonly used in molding propylene polymers are applied. By doing so, a desired molded product can be created. Although the theoretical background of the present invention is not necessarily clear, the styrene polymer uniformly dispersed in the propylene polymer is dissolved in the solvent of paint, printing ink, and adhesive, and the surface of the molded product is physically roughened. Faced. On the other hand, the ethylene-vinyl acetate copolymer or ethylene-acrylic acid ester copolymer uniformly dispersed in the propylene polymer is compatible with components such as paint on the surface of the molded article. On the other hand, the ethylene polymer uniformly dispersed in the propylene polymer seems to exert a synergistic effect because it acts to capture the paint components that have penetrated the surface of the molded article. The molded product obtained in the above manner has excellent adhesion to polypropylene primers whose main components are chlorinated polypropylene, cyclized rubber, hydrochloric acid rubber, etc., and also has good adhesion to modified acrylic paints. has. [] Examples and Comparative Examples The present invention will be explained in more detail below using Examples. In addition, in the Examples and Comparative Examples, the paint film peeling strength test was performed by cutting out a strip of 10 mm wide from the test piece, forcibly peeling off a portion of the paint film from one end of the test piece, and then applying tensile strength to the plastic. The tensile speed is 50 using a tensile testing machine used in tests.
mm/min, the coating film is peeled under conditions of a peeling angle of 180 degrees and a temperature of 20 degrees Celsius, and the strength at that time is the coating peel strength (g/10 mm). In addition, Izot impact strength was measured with a notch according to ASTM D-256. Furthermore, the flexural modulus is ASTM D-
747. The physical properties of the propylene polymer, styrene polymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, and ethylene polymer used in the examples and comparative examples are shown below. show. [(A) Propylene polymer] As a propylene polymer, the density is 0.900g/
cm ³ of propylene-ethylene block copolymer [MFI 4.0 g/10 min, ethylene content 18 weight, hereinafter referred to as "PP(A)"] and propylene homopolymer [MFI 4.0 g/10 min, hereinafter referred to as "PP(A)"]. PP(B)] was used. [(B) Styrene polymer] As a styrene polymer, a styrene homopolymer with an average molecular weight of approximately 300,000 [hereinafter referred to as "PS(I)"]
and a styrenic polymer (hereinafter referred to as "PS()") having an average molecular weight of about 15,000. [(C) Ethylene-vinyl acetate copolymer] Ethylene-vinyl acetate copolymer with a vinyl acetate content of 33% by weight as an ethylene-vinyl acetate copolymer [MI30g/10min, hereinafter referred to as "EVA(1)"] ] and the vinyl acetate content is 55% by weight. Ethylene-vinyl acetate copolymer [MI 15 g/10 minutes, hereinafter referred to as "EVA(2)"] was used. [(D) Ethylene-acrylic ester copolymer] Ethylene-ethyl acrylate copolymer with an ethyl acrylate content of 18% by weight as an ethylene-acrylic ester copolymer [MI6.0g/
10 minutes, hereinafter referred to as "EEA()"] and ethylene-ethyl acrylate copolymer with an ethyl acrylate content of 50% by weight [MI2.5g/10 minutes, hereinafter referred to as "EEA()"]. used. [(E) Ethylene polymer] As an ethylene polymer, an ethylene polymer with a density of 0.950 g/cm ³ [M・I.1.0 g/10 min, hereinafter referred to as "PE(a)"], density low-density polyethylene (MI3.0 g/10 min, hereinafter referred to as "PE(b)") with a density of 0.920 g/ ^{cm 3 and} linear low-density ethylene-butene-1 copolymer with a density of 0.9 g/cm 3 [Butene content 7.0% by weight, MI2.0g/10min, hereinafter referred to as "PE(c)"]
was used. Examples 1 to 8, Comparative Examples 1 to 9 Propylene polymers whose types are shown in Table 1
100 parts by weight and styrenic polymer, ethylene-vinyl acetate copolymer or ethylene-acrylic acid ester copolymer, and ethylene polymer whose types are shown in Table 1 (the amounts of each are shown in Table 1) using a Ripon blender in advance.
Dry blending was performed for 10 minutes. Each of the obtained mixtures was melted and kneaded using a vented extruder (diameter 50 mm) at a resin temperature of 230°C to produce pellets (compositions). Each pellet obtained was injection molded using a 5-ounce injection molding machine at a resin temperature of 230°C to form a flat specimen (150°C).
×150, thickness 2mm). A spray gun was used to apply a primer for Holprene (manufactured by Kawakami Toyo Co., Ltd., trade name: Hi-Plus 150HB) to a thickness of 5 to 10 microns on one side of each test piece obtained in this way for a paint film peeling test. I sprayed it. Subsequently, a two-component urethane paint (manufactured by Nippon B Chemical Co., Ltd., trade name R-264) was sprayed using a spray gun to a thickness of 35 to 40 microns for a paint film peeling test. Subsequently, heat drying was performed at a temperature of 90° C. for 30 minutes. Then, after being allowed to stand overnight at room temperature, each sample was subjected to a coating peel strength test. The results are shown in Table 2. Table 2 also shows the MFI of each of the above pellets, as well as the flexural modulus and Izot impact strength (notched) of each specimen. In Table 1, composition component () represents a propylene polymer, and composition component () represents a styrene polymer. Further, the composition component () represents an ethylene-vinyl acetate copolymer or an ethylene-acrylic acid ester copolymer, and the composition component () represents an ethylene polymer.

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[Table] From the results of the above examples and comparative examples, it is clear that the composition obtained by the present invention not only has good adhesive properties, but also has excellent processability and fluidity (kneadability). Since it has good mechanical properties such as impact resistance and rigidity, it is clear that it can be used in a wide variety of fields as described above.

Claims (1)

[Claims] 1 (A) Melt flow index is 0.01 to 100
g/10 min crystalline propylene polymer 100
parts by weight, (B) 0.5 to 20.0 parts by weight of a styrene-based polymer with a molecular weight of 22,000 to 400,000 as the main component, (C) an ethylene-vinyl acetate copolymer with a vinyl acetate content of 5.0 to 50% by weight; Ethylene-acrylic ester copolymer with a polymer and/or acrylic ester content of 5.0 to 40% by weight
3.0 to 28.0 parts by weight and (D) an olefinic polymer composition comprising 3.0 to 30.0 parts by weight of an ethylene polymer having a density of 0.900 to 0.975 g/cm ³ and a melt index of at least 0.1 g/10 min. thing.