JPH04233959A - Propylene polymer composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a propylene polymer composition that exhibits excellent adhesion to polyurethane resins even without the use of a primer.

0002

[Prior Art] As is well known, polyolefin resins (polypropylene resins, polyethylene resins) not only have excellent moldability, but also have excellent mechanical properties, heat resistance, solvent resistance, oil resistance, and chemical resistance. Because of their excellent properties, they are widely manufactured industrially and used in a wide variety of applications, including parts and packaging materials for automobiles, electrical appliances, and electronic devices, various containers, and other daily necessities. but,
Since it does not have a polar group in its molecule (it is so-called inert), it has poor adhesion to various substances. Of these,
Adhesion with polyurethane resin will be explained.

Currently, exterior parts such as bumpers and bumper corners of automobiles are made of propylene-based polymers containing propylene as the main component, ethylene-propylene copolymer rubber, and inorganic in order to reduce the weight and cost of automobiles. Molding a composition containing a filler (mainly talc),
The molded product is subjected to surface treatments such as electrical treatment (e.g. corona discharge treatment, plasma treatment), mechanical roughening, flame treatment, oxygen or ozone treatment, and is then primed with a primer that has good adhesion to propylene polymers. and coated with polyurethane paint. However, in the step of applying this primer, generally after applying the primer, the primer is completely adhered (baked). This process requires a long time (usually about 40 to 80 minutes). Moreover, a large amount of organic solvent (for example, toluene) must be used to perform the two-coating process, which poses problems in terms of working environment and air pollution.

[0004] Polyurethane foam is also used as a cushioning material for interior parts of automobiles such as instrument panels, armrests, and seat backs by taking advantage of its heat insulating and cushioning properties, and is also used in home appliances such as electric refrigerators and air conditioners. It is used as an insulator for products and refrigerated trucks.

[0005] When polyurethane foam is used in such fields, it is often necessary that the polyurethane foam be firmly adhered to the base material or surface material of the product. By the way, if the base material or surface material is metal, wood or
BS resin (acrylonitrile-butadiene-styrene ternary copolymer resin), which has high surface activity, has excellent adhesion to polyurethane foam, so If the urethane polymer formation reaction and foaming are simultaneously performed on a substrate using a method such as injection foaming, a product (laminate) with strong adhesion can be obtained. However, as mentioned above, it is impossible to manufacture a laminate with polyurethane foam using an inert polyolefin resin as a base material or surface material because the adhesiveness is extremely low. For this reason, when a polyolefin resin and a polyurethane foam are brought into close contact with each other, a primer must be applied in advance to the surface of the polyolefin resin molded product as described above.

[0006] For these reasons, polyolefin resins are made of organic compounds that have at least one double bond in their molecules and contain hydroxyl groups (hereinafter referred to as ``hydroxyl compounds'') and at least organic peroxides. Modified polyolefin resin obtained by treatment with [
Hereinafter referred to as "modified product (A)"] has been proposed for improving the adhesion with polyurethane paints and polyurethane foam (for example, JP-A-58-154732;
No. 58-191706, No. 58-185344, No. 61-272417).

Among polyolefin resins, modified products obtained by treating propylene polymers (polypropylene resins) in the same manner as above, crystalline ethylene-propylene block copolymers, amorphous ethylene-propylene block copolymers, etc. Compositions with polymers, inorganic fillers, etc. not only have excellent adhesion to polyurethane without applying a primer, but also have good flexural modulus and impact resistance at low temperatures, and are easy to process. It also has excellent moldability, so it has previously been proposed that it can be molded to be used as exterior parts of automobiles such as bumpers (for example, JP-A-62-119243, JP-A-62-209150, JP-A-62-209150; No. 62-207344,
No. 62-257945).

Furthermore, the composition of the modified product (A) and a crystalline ethylene-propylene block copolymer, ethylene-vinyl acetate copolymer, etc. can be used as a chloroprene-based two-component mixed type solvent without applying a primer. It not only has good adhesion with adhesives at room temperature, but also has excellent adhesion at temperatures of 80°C, and also has good flexural modulus and impact resistance, making it suitable for automobile interior parts (e.g. , door liner) has previously been proposed (Japanese Unexamined Patent Publications Nos. 64-29446 and 64-36).
No. 636, No. 64-45446, No. 64-48842
No. 64-72946).

[0009] In addition, a polyurethane foam and a modified product (A) obtained by simultaneously carrying out a urethane polymer production reaction and foaming on the surface of a molded product of the modified product (A)
It has previously been proposed that the mutual adhesion of a laminate consisting of a molded article and a molded article is improved (for example, JP-A-58-185244, JP-A-58-194834, and JP-A-58-194835).

Furthermore, some of the inventors of the present invention have proposed that ``the ethylene-vinyl acetate copolymer is treated with a hydroxyl compound and an organic peroxide, or with an organic tin compound and/or a tertiary amine compound. "Modified ethylene polymer obtained by
B)'' was found to have superior adhesion to polyurethane paints and polyurethane foams compared to when non-polar polyolefin resins such as polypropylene resins were treated in the same way. (Unexamined Japanese Patent Publications No. 1-2989410 and 1-315460)
.

[0011]

[Problems to be Solved by the Invention] The modified product (A) obtained by treating a polyolefin resin such as the polypropylene resin with at least a hydroxyl compound and an organic peroxide can be used in combination with polyurethane paints and polyurethane foams. Adhesion can be improved. However, in practical terms, the adhesion is not necessarily sufficient. In particular, compositions of the modified product (A) and the above-mentioned polypropylene resins (e.g., propylene homopolymer, crystalline ethylene-propylene block copolymer) can be used as exterior and interior parts of automobiles, as described above. Form into
If a polyurethane paint or a polychloroprene adhesive is applied without applying a primer, the adhesion with these paints is not necessarily sufficient and there are problems in use.

Furthermore, the modified product (B) previously proposed by some of the present inventors has better adhesion to polyurethane paints and polyurethane foams than the modified product (A) and its compositions, as described above. Can improve sex. However, it cannot be said that the modified product (B) has a practically sufficient rigidity (flexural modulus).

Based on these facts, the present invention has extremely good adhesion to polyurethane paints and polyurethane foam without using a primer, and has excellent mechanical properties such as flexural modulus (rigidity) and impact resistance. is good,
Furthermore, the purpose is to produce a composition that has excellent moldability and processability and is suitable for the exterior and interior parts of automobiles.

[0014]

[Means for Solving the Problems] The present invention has solved these problems, and the gist thereof is (A) a propylene homopolymer having a xylene soluble content of at most 5% at a temperature of 30°C and/or A propylene-ethylene random copolymer having an ethylene copolymerization ratio of at most 10% by weight, (B) a xylene insoluble content at a temperature of 30°C of at most 5%, and a propylene copolymerization ratio of 30 to 75%;
% by weight of ethylene-propylene random copolymer,
(C) Ethylene-vinyl acetate copolymer grafted with a hydroxy compound [hereinafter referred to as "modified ethylene-vinyl acetate copolymer"] (D) A composition consisting of an inorganic filler, (E) Propylene homopolymer The composition ratio of the ethylene-propylene random copolymer to the total amount of the combined, propylene-ethylene random copolymer and ethylene-propylene random copolymer is 5.0 to 40% by weight, and the modified ethylene-vinyl acetate The ratio of the hydroxyl compound to 100 parts by weight of the copolymer is 0.01 to 20 parts by weight,
A propylene polymer in which the composition ratio of the modified ethylene-vinyl acetate copolymer in the composition is 5 to 50% by weight, and the composition ratio of the inorganic filler in the composition is 2.0 to 25% by weight. Composition. It is. The present invention will be explained in detail below.

(A) Propylene homopolymer and propylene-ethylene random copolymer The propylene homopolymer used in the present invention is obtained by homopolymerizing propylene. In addition, the propylene-ethylene random copolymer is at most 10% by weight (preferably 9.0% by weight) of propylene.
Hereinafter, it is preferably obtained by copolymerizing ethylene (7.0% by weight or less). These propylene homopolymers and propylene-ethylene random copolymers each contain at most 5% (preferably 3% or less) of a component that is soluble in xylene at a temperature of 30°C. Furthermore, the MF of these polymers
Generally, R is preferably 20 to 100 g/10 min. If the MFR of the propylene homopolymer and propylene-ethylene random copolymer is less than the lower limit, the kneading properties and the moldability of the composition will be poor; on the other hand, if it exceeds the upper limit, the impact resistance of the composition will be poor. is not good.

(B) Ethylene-Propylene Random Copolymer Furthermore, in the present invention, an ethylene-propylene random copolymer is used to improve impact resistance. The copolymerization ratio of propylene in the ethylene-propylene random copolymer is 30 to 75% by weight, preferably 30 to 70% by weight, and particularly preferably 35 to 70% by weight. If an ethylene-propylene random copolymer with a propylene copolymerization ratio of less than 30% by weight is used, the impact resistance of the composition will be poor. On the other hand, ethylene-propylene random copolymers in which the ethylene copolymerization ratio exceeds 75% by weight are not only difficult to manufacture, but also have problems in terms of the rigidity of the composition.

The ethylene-propylene random copolymer contains at most 5% by weight (preferably 4.5% by weight or less) of components insoluble in xylene at a temperature of 30°C. Further, the MFR of the ethylene-propylene random copolymer is usually 0.01 to 5.0 g/10 min for the same reason as the propylene homopolymer and propylene-ethylene random copolymer.

These propylene homopolymer, propylene-ethylene random copolymer and ethylene-propylene random copolymer are each produced by homopolymerization or copolymerization, and when producing the composition of the present invention, or beforehand, propylene monopolymer is The polymer and/or the propylene-ethylene random copolymer and the ethylene-propylene random copolymer may be mixed, and this mixture and other composition components may be mixed in the composition ratios described below, or the propylene homopolymer may be mixed in advance. Copolymerizing and/or producing propylene-ethylene random copolymers and copolymerizing ethylene and propylene in the same polymerization vessel or in separate polymerization vessels in the presence of these polymers and the catalyst system used to produce the polymers. It may also be produced by so-called block copolymerization.

In any of the above cases, the MFR of the total amount of propylene homopolymer and/or propylene-ethylene random copolymer and ethylene-propylene random copolymer is 2.0 to 100 g/10 minutes,
5.0 to 70 g/10 min is preferable, especially 5.0 to 50 g/10 min.
g/10 minutes is preferred. M of the total amount of propylene homopolymer and/or propylene-ethylene random copolymer and ethylene-propylene random copolymer
When the FR is less than 2.0 g/10 minutes, the kneading properties and moldability of the composition are poor.

On the other hand, if it exceeds 100 g/10 minutes, the mechanical properties of the composition, particularly the impact resistance, will be poor. Also,
The content of ethylene in the total amount of these polymers is generally 1.0 to 25% by weight as a monomer unit, and 2.
．． It is preferably 0 to 20% by weight, particularly preferably 3.0 to 20% by weight. If the content of ethylene in the total amount of these polymers is less than 1.0% by weight as a monomer unit, there is a problem in the impact resistance of the composition. On the other hand, if it exceeds 25% by weight, there is a problem in terms of the rigidity of the composition.

(C) Modified ethylene-vinyl acetate copolymer The modified ethylene-vinyl acetate copolymer, which is a component of the composition of the present invention, is produced from an ethylene-vinyl acetate copolymer. The copolymerization ratio of vinyl acetate in the copolymer is 3.0 to 40% by weight, and 3.5 to 3% by weight.
5% by weight is preferred, particularly 5.0 to 35% by weight. If the copolymerization ratio of vinyl acetate in the ethylene-vinyl acetate copolymer is less than 3.0% by weight, the adhesion to polyurethane paints and polyurethane foam will be low. On the other hand, 40
When using an ethylene-vinyl acetate copolymer exceeding
Physical properties such as rigidity and impact resistance of the composition deteriorate.

The melt flow index of the ethylene-vinyl acetate copolymer [measured according to JIS K7210 under conditions 4 in Table 1, hereinafter referred to as "MFR(2)"] is generally 0.1 to 200 g/ 10 minutes and 0.
1 to 150 g/10 minutes is desirable, especially 0.5 to 1
00 g/10 minutes is suitable. MFR (2) is 0.1g
/ When using an ethylene-vinyl acetate copolymer for less than 10 minutes, not only will the kneading properties be poor when producing the following treatment by melt kneading, but also the kneading properties and molding of the composition will be poor when producing the composition. I don't have good sex. On the other hand, 200g/10
If it exceeds 10 minutes, the mechanical strength will be low.

Hydroxyl compound Furthermore, the hydroxyl compound used to produce the modified ethylene-vinyl acetate copolymer, which is a component of the present invention, has at least one double bond and is an organic compound having a hydroxyl group. It is a compound. The general formula of the hydroxyl compound is usually represented by the following formula [Formula (I)].

[0024]

[Formula 1] In formula (I), R1 is a hydrogen atom or has 1 carbon atom
~6 alkyl groups. Also, R2 has 1 carbon number
~20 alkylene groups. In formula (I), R
1 is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, particularly preferably a hydrogen atom, a methyl group, or an ethyl group. Further, R2 is preferably an alkylene group having 1 to 6 carbon atoms, particularly preferably an alkylene group having 1 to 4 carbon atoms. Suitable hydroxyl compounds include 2-
Hydroxy-ethyl-methacrylate, 2-hydroxy-ethyl-acrylate, 2-hydroxy-propyl-
Mention may be made of methacrylate and 2-hydroxy-methyl-methacrylate.

Organic peroxide The organic peroxide used in the production of the modified ethylene-vinyl acetate copolymer of the present invention is generally used as an initiator in radical polymerization and as a crosslinking agent for polymers. , those with a half-life of 1 minute of 100°C or more are preferred, and those with a 1-minute half-life of 110°C or more are particularly preferred. If the temperature is less than 100° C., it is not only difficult to handle, but also the effect of using it is not very noticeable, so it is not desirable. Representative examples of preferred organic peroxides include 1,1-bis-tert-butylperoxy-3,3,5
- ketone peroxides such as trimethylcyclohexane, dialkyl peroxides such as dicumyl peroxide, hydroperoxides such as 2,5-dimethylhexane-2,5-hydroperoxide, diacyl peroxides such as benzoyl peroxide, and 2,
Examples include peroxy esters such as 5-dimethyl-2,5-dibenzoyl peroxyhexane.

The modified ethylene-vinyl acetate copolymer of the present invention is obtained by treating the above-mentioned ethylene-vinyl acetate copolymer with a hydroxyl compound and an organic peroxide. Alternatively, the reactivity can be improved by adding a tertiary amine compound to the treatment.

Organotin compound Examples of the organotin compound include those represented by the following formula [Formula (II)].

[0028]

[Image Omitted] In formula (II), R3, R4, R5 and R
6 may be the same or different and is a hydrocarbon group having at most 12 carbon atoms; Y1 and Y2 may be the same or different and are monovalent or divalent carboxylic acids having at most 18 carbon atoms; They are derivatives of carboxylic acids (alkyl esters), alcohols, mercaptans, and mercapto acids. X1 is an oxygen atom, a sulfur atom, and a carboxylic acid group having at most 4 carbon atoms and a double bond; 1 is 0 or an integer from 1 to 20;

Typical examples of this organic tin compound include monobutyl tin trimethyl malate, dibutyl tin dilaurate, a mixture of dibutyl tin dimalate and dibutyl tin dimethyl maleate, and dibutyl tin dioctyl malate. Examples include tribenzyl tin trimethyl malate and tribenzyl tin trimethyl malate.

Tertiary amine compounds Furthermore, tertiary amine compounds are used as catalysts in the curing reaction of so-called urethane polyols and isocyanates. As a typical example,
Dimethylaminopropylamine, diethylaminopropylamine, tris(dimethylaminomethyl)phenol, tetraguanidine, N,N-dibutylethanolamine, N-methyl-N,N-diethanolamine, 1,4
-diazabicyclo(2,2,2)octane and 1,8
-Diazabicyclo(5,4,0)-7 undecene.

Usage ratio In producing the modified ethylene-vinyl acetate copolymer of the present invention, the hydroxyl compound, organic peroxide, organic tin compound and tertiary compound are added to 100 parts by weight of the ethylene-vinyl acetate copolymer. The proportion of the grade amine compound used is as follows.

The ratio of hydroxyl compound used is 0.1
~20 parts by weight, preferably 0.1 to 15 parts by weight,
Particularly suitable is 0.2 to 15 parts by weight. If the proportion of the hydroxyl compound used is less than 0.1 part by weight, the effect of improving adhesion is insufficient. On the other hand, if it exceeds 20 parts by weight,
No improvement in adhesion was observed depending on the amount used.

[0033] Furthermore, the proportion of organic peroxide used is 0.01
~10 parts by weight, preferably 0.02 to 10 parts by weight, particularly preferably 0.05 to 7.0 parts by weight. If the proportion of organic peroxide used is less than 0.01 parts by weight, the effect of improving adhesion is low. On the other hand, even if it is used in an amount exceeding 10 parts by weight, not only the adhesion cannot be further improved, but also the ethylene-vinyl acetate copolymer itself may be crosslinked, which is not preferable.

Furthermore, when using an organic tin compound and a tertiary amine compound, the mixing ratio thereof is at most 10 parts by weight individually or in total, and preferably 5.0 parts by weight or less. , especially 0.05-3
Parts by weight or less are preferred. Even if the total mixing ratio of the organic tin compound and the tertiary amine compound exceeds 10 parts by weight, the effect will not be improved and, on the contrary, adverse effects such as bleeding may occur.

Processing method To produce the modified ethylene-vinyl acetate copolymer of the present invention, the above-mentioned ethylene-vinyl acetate copolymer, hydroxyl compound, organic peroxide, or these together with an organic tin compound and/or When producing a normal modified olefin polymer in which the tertiary amine compound is used in the above ratio, any of the commonly practiced methods (for example, solution method, suspension method, melt method) is used. This can be achieved by adopting and processing. Among these processing methods, the melt method is industrially desirable because of its short processing time and the need for no post-treatment (eg, removal of organic solvents and water).

When producing a modified ethylene-vinyl acetate copolymer by the melt method, kneading machines such as Banbury mixers, kneaders, roll mills, and screw extruders (especially screw extruders) commonly used in the field of general synthetic resins are used. It can be produced by melt-kneading using a type extruder (preferable because it is simple). At this time, a more uniform modified ethylene-vinyl acetate copolymer is produced by dry blending in advance using a mixer such as a Henschel mixer and then melt-kneading the resulting mixture, or by performing melt-kneading two or more times. can do. Melt-kneading must be carried out at a temperature at which the organic peroxide used is decomposed. However, it goes without saying that the ethylene-vinyl acetate copolymer used must not deteriorate and the treatment must be carried out at a temperature that can be controlled. For these reasons, the treatment temperature is generally 100 to 250°C, particularly preferably 120 to 230°C.

The modified ethylene-vinyl acetate copolymer thus obtained contains unreacted (ungrafted)
Some hydroxyl compounds may remain. At this time, the hydroxyl compound is used in the production of the composition described later without being removed. Additionally, ungrafted ethylene-vinyl acetate copolymer may be present. At this time, the ungrafted ethylene-vinyl acetate copolymer is similarly used in the production of the composition described later without being removed.

(D) Inorganic filler In the present invention, an inorganic filler is used to improve the flexural modulus. Inorganic fillers are generally widely used in the fields of synthetic resins and rubbers. These inorganic fillers are preferably inorganic compounds that do not react with oxygen and water and do not decompose during kneading and molding. The inorganic fillers include metals such as aluminum, copper, iron, lead and nickel, oxides of these metals and metals such as magnesium, calcium, barium, zinc, zirconium, molybdenum, silicon, antimony and titanium, and their water. It is broadly classified into compounds such as hydrates (hydroxides), sulfates, carbonates, silicates, their double salts, and mixtures thereof.

A representative example of the inorganic filler is disclosed in Japanese Patent Application No. 59-85.
It is described in the specification of No. 35. Among these inorganic fillers, those in powder form preferably have a diameter of 30 microns or less (preferably 10 microns or less). In addition, in the case of fibrous materials, the diameter is 1 to 500 microns (preferably 1 to 3 microns).
00 microns) and a length of 0.1 to 6 mm (preferably 0.1 to 5 mm). Furthermore, it is preferable that the diameter of the flat plate is 30 microns or less (preferably 10 microns or less). Among these inorganic fillers,
Particularly suitable are plate-like (flake-like) ones and powder-like ones. Suitable inorganic fillers include talc, mica, silica, glass fibers, potassium titanate whiskers, graphite, and the like.

(E) Composition ratio In the composition of the present invention, the propylene homopolymer,
The composition ratio of the ethylene-propylene random copolymer in the total amount of the propylene-ethylene random copolymer and the ethylene-propylene random copolymer is 5.0.
-40% by weight, preferably 5.0-35% by weight,
Particularly suitable is 7.0 to 35% by weight. If the composition ratio of the ethylene-propylene random copolymer to the total amount of the propylene homopolymer, propylene-ethylene random copolymer and ethylene-propylene random copolymer is less than 5.0% by weight, the resulting composition impact resistance,
In particular, impact resistance at low temperatures is poor. On the other hand, 40
If it exceeds % by weight, the stiffness of the composition is poor.

The proportion of the hydroxyl compound to 100 parts by weight of the modified ethylene-vinyl acetate copolymer is 0.01 to 20 parts by weight, preferably 0.02 to 15 parts by weight, particularly 0.1 parts by weight. ~10 parts by weight is preferred. If the ratio of the hydroxyl compound to 100 parts by weight of the total amount of the modified ethylene-vinyl acetate copolymer is less than 0.01 parts by weight, the adhesion to the polyurethane resin will be poor. On the other hand, even if the amount exceeds 20 parts by weight, no improvement in adhesion is observed in proportion to the proportion.

The composition ratio of the modified ethylene-vinyl acetate copolymer in the composition is 5 to 50% by weight,
10 to 45% by weight is desirable, and 15 to 40% by weight is suitable. If the amount of the modified ethylene-vinyl acetate copolymer in the composition is less than 5% by weight, there will be problems in adhesion to polyurethane. On the other hand, if it exceeds 50% by weight, the flexural modulus of the resulting composition will decrease significantly.

The composition ratio of the inorganic filler in the composition obtained in the present invention is 2.0 to 25% by weight, and 2.0 to 25% by weight.
．． 5 to 25% by weight is preferred, especially 3.0 to 20% by weight
is suitable. If the proportion of the inorganic filler in the composition is less than 2.0% by weight, the flexural modulus of the resulting composition will not be improved. On the other hand, if it exceeds 25% by weight, not only will the impact resistance of the composition at low temperatures be poor;
It may cause silver to form during molding. In order to prevent the formation of silver, there is a method of pre-drying the composition, but this is not a good idea when mass producing large molded products such as bumpers.

(F) Production of Composition The propylene polymer composition of the present invention comprises the propylene homopolymer and/or propylene-ethylene random copolymer, ethylene-propylene random copolymer and modified ethylene-vinyl acetate copolymer. It can be manufactured by uniformly mixing a polymer and an inorganic filler in the above composition ratio range. When producing the composition of the present invention, stabilizers against oxygen, heat and ultraviolet rays, metal deterioration inhibitors, flame retardants, colorants, electricity, etc., which are commonly used in the field of polyolefin resins, are used depending on the purpose of use. Additives such as physical property improvers, fillers, antistatic agents, lubricants, processability improvers, and tackiness improvers may be mixed as long as they do not impair the properties of the modified ethylene polymer of the present invention. You may.

The compositions of the invention may be prepared by dry blending using mixers such as Henschel mixers, or by using mixers such as Banbury mixers, kneaders, roll mills and screw extruders. It may be melt-kneaded. At this time, a more uniform composition can be obtained by performing dry blending in advance and further melt-kneading the resulting mixture, or by performing melt-kneading two or more times.

(G) Molding method The propylene polymer composition obtained as described above can be produced into a desired molded article by a molding method commonly used in the field of polyolefin resins. Examples of the molding method include injection molding, extrusion molding, blow molding, stamping molding, compression molding, and vacuum molding. A molded product whose surface is coated with polyurethane can be obtained by applying a polyurethane paint to the molded product thus obtained using a commonly used method. Further, in order to adhere closely to the polyurethane foam, the urethane polymer formation reaction and foaming may be simultaneously performed on the surface of the molded product obtained as described above.

[0047] To achieve close contact, no special equipment or special method is required. That is,
Foaming methods commonly used in the field of polyurethane foam manufacturing such as injection foaming, mold foaming, and spray foaming may be used. Furthermore, the polyol, isocyanate compound, blowing agent, etc. used as raw materials for polyurethane foam do not need to be special materials, and any commonly used materials may be used without any limitation.

[0048]

[Function] Although the mechanism of the development of adhesion between the propylene polymer composition obtained by the method of the present invention and polyurethane is not clear, it is presumed to be due to the following mechanism of action. In the modified ethylene-vinyl acetate copolymer in the propylene-based polymer composition obtained by the method of the present invention, a hydroxyl-based compound is bonded to the ethylene-vinyl acetate copolymer by the above-mentioned treatment, and the hydroxyl group (- By bonding the isocyanate group of polyurethane with OH), strong adhesion is developed between, for example, a polyurethane paint and a molded article of a modified ethylene-vinyl acetate copolymer.

[0049] Furthermore, the ethylene-vinyl acetate copolymer is
For example, compared to polyolefin resins that do not have polar groups, such as polyethylene resins and polypropylene resins, they have superior wettability, so compounds with isocyanate groups in polyurethane paints do not get close to the surface of the copolymer. The reaction rate between isocyanate groups and hydroxyl groups increases, resulting in stronger adhesion.

Furthermore, when an organotin compound and/or a tertiary amine are used in the production of a modified ethylene-vinyl acetate copolymer, they are used in the curing reaction between the polyol and isocyanate compound of the so-called polyurethane resin. It is thought that stronger adhesion is developed because it acts as a catalyst and promotes the reaction between the hydroxyl groups of the resulting modified ethylene polymer and the isocyanate groups in the polyurethane paint or polyurethane foam.

[0051]

[Examples] The present invention will be explained in more detail with reference to Examples below. In the Examples and Comparative Examples, the adhesion strength of the coating film was determined by making a 1 cm wide stripe on a molded flat plate and measuring the 180°C peel strength of the coating film at a tensile rate of 50 mm/min. In addition, the Izod impact strength is 2 with a notch according to ASTM D256.
Measurements were made at a temperature of 3°C. Furthermore, the flexural modulus is A
Measured according to STM D790. In addition, the propylene polymer used in Examples and Comparative Examples and the ethylene-vinyl acetate copolymer, hydroxyl compound, organic peroxide, organic tin compound, and tin compound used in the production of the modified ethylene-vinyl acetate copolymer were The physical properties of the tertiary amine are shown below.

[(A) Propylene polymer] and [(B
) Ethylene-propylene random copolymer] The following polymer was used as the propylene-based polymer. Only propylene was polymerized using a Ziegler-Natta catalyst in a polymerization vessel without using a solvent. Then, ethylene was supplied to this polymerization vessel to produce a random copolymer of ethylene and propylene. The obtained propylene polymer [hereinafter referred to as “P
P(A)] is a propylene homopolymer (MFR
Ethylene-propylene random copolymer (MFR 0.1 g/10 min, 60 g/10 min, containing 75 wt. (all soluble in xylene at a temperature of 30°C). The MFR of this PP(A) was 13 g/10 minutes. For comparison, a propylene homopolymer [MFR 20 g/10 min, hereinafter referred to as "PP(B)"] produced by a similar method was used.
] was used.

[(C) Modified ethylene-vinyl acetate copolymer] In order to produce this copolymer, the copolymerization ratio of vinyl acetate is 6.2% by weight, and the MFR An ethylene-vinyl acetate copolymer (hereinafter referred to as "EVA (1)") in which (2) is 19 g/10 minutes, and a copolymerization ratio of vinyl acetate is 24% by weight, and MFR (2) is 20 g/10 min. Ethylene-vinyl acetate copolymer [hereinafter referred to as "EVA (2)"]
and the copolymerization ratio of vinyl acetate is 35% by weight,
An ethylene-vinyl acetate copolymer [hereinafter referred to as "EVA (3)"] having an MFR of 30 g/10 minutes was used.

[Hydroxyl Compound] Furthermore, 2-hydroxyl-ethyl methacrylate (hereinafter referred to as "HEMA") was used as a hydroxyl compound. [Organic Peroxide] Dicumyl peroxide (hereinafter referred to as "DCP") was also used as an organic peroxide. [Organotin compound] Further, as an organic tin compound, dibutyl tin malate [hereinafter referred to as "compound (1)"] and dibutyl tin laurate [hereinafter referred to as "compound (1)"]
2). [Tertiary amine compound] 1,4-diazabicyclo[2,2,2]octane [hereinafter referred to as "compound (3)"] was used as a tertiary amine compound. [(D) Inorganic filler] As an inorganic filler, the average particle size is 2
Talc having a diameter of 15 μm and potassium titanate whiskers having an average fiber length of 15 μm and an average fiber diameter of 0.5 μm were used. [Production of modified ethylene-vinyl acetate copolymer] HE whose blending amount is shown in Table 1 is added to 100 parts by weight of the ethylene-vinyl acetate copolymer whose type is shown as the resin component in Table 1.
MA (2-hydroxyl-ethyl-methacrylate, as a hydroxyl-based compound), DCP (dicumyl peroxide, as an organic peroxide), and an organotin compound or a tertiary amine-based compound were each mixed for 10 minutes using a super mixer. I did a dry blend. Each of the obtained mixtures was passed through a vented twin-screw extruder (diameter 40
mm) at 180°C while pellets [modified ethylene-vinyl acetate copolymer, hereinafter "modified EV
A) was produced. Table 1 shows the abbreviations of each modified EVA obtained.

Examples 1 to 13, Comparative Examples 1 to 3 Propylene polymers, modified EVA, and inorganic fillers whose types and amounts are shown in Table 2. Twin screw extruder with vent (dia.
Pellets (composition) were produced while kneading the resin at a resin temperature of 210° C. using a 30 mm-thick resin. Each of the obtained pellets was injection molded at a resin temperature of 210°C, and a flat specimen (2 mm thick, 120 x 120 m
Samples were prepared to measure the Izod impact strength and flexural modulus.

[0056] A two-component polyurethane paint (manufactured by Nippon P Chemical Co., Ltd., trade name: R271, Pure White) was uniformly sprayed onto each of the test pieces thus obtained using a spray gun. . Then, it was heated and dried at a temperature of 60° C. for 90 minutes. The coating film adhesion strength of each specimen thus obtained was measured. In addition, the Izod impact strength and flexural modulus of each of the test pieces were measured. The results are shown in Table 2.

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

Effects of the invention: The propylene polymer composition obtained by the method of the present invention has excellent adhesion to polyurethane paints even without the use of a primer, and also has excellent adhesion to polyurethane adhesives and polyurethane foam. It is also good. As a result, it is possible to improve productivity by omitting steps such as applying a primer and drying the resulting molded product, and to significantly improve adhesion with these polyurethane-based paints, adhesives, and foams.

The propylene polymer composition obtained by the method of the present invention can be used in a wide variety of ways in order to exhibit the above-mentioned effects. Typical applications include exterior parts such as automobile bumpers and bumper corners, interior parts such as instrument panels and door liners, and motorcycle parts such as fenders.

Claims (1)

[Claims] Claim 1: (A) A propylene homopolymer having a xylene soluble content of at most 5% at a temperature of 30°C and/or
or a propylene-ethylene random copolymer in which the copolymerization ratio of ethylene is at most 10% by weight, (B) 30
an ethylene-propylene random copolymer having a xylene insoluble content of at most 5% at a temperature of °C and a propylene copolymerization ratio of 30 to 75% by weight, (C) containing one double bond, and A composition consisting of an ethylene-vinyl acetate copolymer grafted with an organic compound containing a hydroxyl group, (D) an inorganic filler, and (E) a propylene homopolymer, a propylene-ethylene random copolymer, and ethylene-propylene. The composition ratio of the ethylene-propylene random copolymer in the total amount of the random copolymer is 5.0 to 40% by weight, and the organic compound is The proportion of the compound is 0.01 to 20 parts by weight, the proportion of the ethylene-vinyl acetate copolymer grafted with the organic compound in the composition is 5 to 50 parts by weight, and the proportion of the inorganic filler in the composition is 5 to 50 parts by weight. The composition ratio is 2.0~
25% by weight of a propylene-based polymer composition.