JPS608347A - Adhesive polypropylene composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition having excellent adhesivity to polyolefin molded article, metal, wood, etc., by compounding an ethylene polymer, etc. to a modified polypropylene grafted with an unsaturated carboxylic acid, etc. and unmodified polypropylene. CONSTITUTION:A mixture of (A) a modified crystalline polypropylene grafted with an unsaturated carboxylic acid (anhydride) (preferably maleic anhydride) and (B) an unmodified crystalline polypropylene, is mixed with one or more compounds selected from (C) an ethylene polymer (preferably a low density polyethylene, etc.) and (D) a styrene copolymer (preferably styrene-butadiene copolymer elastomer, etc.), under melting preferably at 170-250 deg.C to obtain the objective composition. The component A is preferably the one having a grafting ratio of the unsaturated carboxylic acid (anhydride) of 0.1-4wt%, and containing 0.1-1wt% said unsaturated carboxylic acid (anhydride) as free state.

Description

[Detailed description of the invention] Undeveloped IJI has adhesive polypropylene composition 11.14.7
In addition, the bone is modified by graft polymerization of anhydride of unsaturated carboxylic acid. , p of polypropylene and unmodified polypropylene, +,
(y.

The composition is prepared by melt-mixing one or two polymers selected from ethylene polymers and styrene copolymers to the material.

Since polyolefins such as polyzolopyrene and polyethylene are nonpolar compounds, they are chemically stable and have a variety of excellent properties, but on the other hand, they have no affinity with shuttle compounds and are highly susceptible to metals and other shuttle compounds. It is difficult to bond with resin, so there are restrictions on its uses. For this reason, modified F'l polyolefins, which are produced by graft polymerizing polyolefins with unsaturated carboxylic acids and the like, have been well known as adhesive polyolefins, and many methods have been developed for producing them. The unsaturated carboxylic acid used for the modification is typically maleic anhydride or acrylic acid-modified polyolefin. The above-mentioned modified polyolefin has good adhesion to metals, inorganic materials, or polymeric materials, and is therefore widely used as adhesives for metal coating materials, lamination adhesives for various materials, and the like.

However, in modified polyolefins obtained by graft polymerization reaction of polyolefins and unsaturated carboxylic acids, unsaturated carboxylic acids, that is, unreacted monomers, often remain, and this monomer causes modified polyolefins to emit a pungent odor or have poor adhesive properties. There are problems such as being inhibited.

To solve this problem, as a method to improve adhesion, there is a method of extracting unreacted monomers with a solvent (Japanese Unexamined Patent Application Publication No. 1987-
9!11193), ■Method of removing unreacted monomers by heating (Japanese Unexamined Patent Publication No. 56-95814. No. 57-940)
33° times 57-94034) and the method of adding Φ inorganic compounds (Japanese Patent Publication No. 50-2631. Japanese Patent Publication No. 48-10
38) and the like have been proposed, but none of them can be said to be sufficiently effective in improving adhesion. In addition, grafting of unsaturated carboxylic acids; a method of improving adhesion by directing V is a method of adding molten rubber to a resin, and sometimes adding diene rubber, etc. at the same time (
Special Publication No. 55-5788, No. 55-18251, No. 5
3-[f200 Kano) is I! Four methods have been proposed, but these methods have the disadvantage of insufficient adhesion and foaming during molding.

The present inventors have made earnest efforts to solve the above-mentioned technical problem regarding the removal of unreacted slag from adhesive polyolefin compositions. As a result, by mixing one or more of the following two unmodified polymers, namely ethylene polymers and styrene copolymers, with the modified polyolefin and crystalline polypropylene described in -. He completed the invention of wood after realizing that the problems listed in item 1-1 could be solved economically.

As described above, the present invention provides a mixture of the above-mentioned modified polypropylene containing unreacted monobutylene and unmodified 1 It is an object of the present invention to provide a method for solving the problem described in -1- above by melting and mixing one or two types of polymers.

The present invention has the following main configuration (1) and the following (2) to (3).
It has an embodiment configuration.

(+) Unsaturated carboxylic acid or its anhydride) One or two selected from [-] Crystalline bonopropylene A modified by craft polymerization of the compound [-] and unmodified crystalline polypropylene B4 On the other hand, an adhesive polypropylene M1 composition is prepared by blending an ethylene polymer C and one or two polymers selected from styrene polymers.

(2) Modified polypropylene A with a grafting rate of 0.1 to 4 ton 1i of unsaturated carbonic acid or its anhydride
1%, 11. Modification of the It synthetic acid (3) according to the above item (1), which contains 0.1 to 1% of the unsaturated 1-carboxylic acid or its anhydride in free radical state. Polypropylene A and unmodified polypropylene 1) One or more compounds selected from ethylene polymer C and styrene copolymer are added to propylene H.
The composition according to item (1) above, which is melt-mixed at 70 to 250°C.

The structure and effects of the wooden invention will be described in detail below.

(1) Crystalline polypropylene for modification used in the present invention: A propylene Qt homopolymer which is crystalline in Mizuhiki, a propylene-ethylene block or random copolymer having a propylene polymer portion content of 50 tonkuma% or more, Propylene-ethylene-butene-1 block or random copolymer and propylene-butene-1 random copolymer e with melt flow rate 0.01-50
(g/40 minutes) Dr. preferably 0.1-10 (g/1
0 minutes).

Anhydrides of unsaturated carboxylic acids and 71゛σL used in the present invention: Examples of the carboxylic acids include maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, and incrotonic acid. Examples of the anhydride include maleic anhydride, citraconic anhydride, and itaconic anhydride. Among them, maleic anhydride is easy to use and provides favorable results. The amount of these used is 0.2% to 5%, preferably 0.5% to 2%, based on the above-mentioned modified crystalline polypropylene according to the present invention.

(i) If the usage amount is less than 0.2%, the content of unreacted monomer required in the mixing reaction of the modified polypropylene and the blending polymer will be small and the improvement effect of mixing will be insufficient; The melt flow rate of the modified polypropylene becomes abnormally high, making it impossible to maintain the basically necessary physical properties as a polymer, and the amount of unreacted monomer increases, even after the mixing reaction with the blending polymer mentioned above. Note that unreacted monomer remains, making it difficult to achieve the object of the present invention.

C9 Unmodified crystalline polypropylene B used in the present invention: One or more of the polypropylenes shown in item A above can be used. These are a combination of modified polypropylene A and unmodified crystalline polypropylene B, with a weight ratio of 1 to 10.
~90%, preferably 30-85% can be used. If it exceeds 90%, the unique effect of modified polypropylene A becomes unclear.

20 Ethylene polymer C and styrene copolymer D used in the present invention = These are melt-mixed directly with modified polypropylene A or, if necessary, with unmodified polypropylene B. is 5 to 25% by weight of the entire M1 composition. Not only will the properties of the polypropylene resin be impaired, but the adhesive strength will also be reduced.

The ethylene polymers used in the present invention include ethylene-vinyl acetate conjugates of ethylene such as low-density polyethylene, medium-density polyethylene, and high-density polyethylene, and ethylene-1-thyl acrylate-1 copolymers. can. It may also be a copolymer elastomer with propylene containing ethylene as a main component, or a ternary copolymer elastomer with propylene-ethylidene norbornene. Among these, low-density polyethylene, ethylene-vinyl acetate symbiotic combination, and copolymer elastomer are particularly preferred. In addition, the styrene copolymers used in the present invention include styrene-butadiene copolymer Elas I, marstyrene-
Isoprene copolymer elastomers are preferred.

E8 Method for producing modified polypropylene according to the present invention 2 The method for producing modified polypropylene according to the present invention is based on a heating melt reaction, and this method is particularly effective for a melt reaction method using a one- or two-car extruder. That is, the above-mentioned crystalline polypropylene powder (A) is mixed with an unsaturated carboxylic acid or its anhydride at the above-mentioned ratio (IJ ratio of 0.2 to 5%), and then mixed with a high-speed mixer such as a Henschel mixer (trade name).
etc. to mix uniformly and then perform the subsequent melting reaction. The melting reaction can be carried out only by heating, but it is also possible and preferable to use a method of generating radicals using an organic peracetate as described below. Preferred conditions for the melt reaction are in the range of 170-250'O, 1 minute to 10 minutes (note: extrusion 4%, 17j) residence time).

(1) Perboxanate used in the embodiment of the present invention: A perboxate that decomposes at an appropriate rate within the range of the melting reaction temperature (170-250°C) mentioned above is desirable. Jl, body side: benzoyl peroxide, dicumyl peroxide, 2
, 5-dimethyl(t-bugolpar-A-gish)hexane,
1,3-bis(E-butylperoxyisopropyl)benzene and the like. The additive amount of the SPA oxide is 0.01 to 0.2% by weight relative to the modified crystalline polypropylene. 0.01% not in the river? At /4, the effect of addition is unclear, and at more than 0.2 weight percent, the melt flow rate may become abnormally high, in which case the composition of the present invention loses its necessary properties.

Method of mixing ethylene polymer C and/or styrenic copolymer (■) with modified polypropylene A8 and unmodified polypropylene B according to the invention: Modified polypropylene A, unmodified polymer 11 P1.・N B
, the ethylene base C and/or the styrene base material are mixed in a heated and molten state. The mixing mode is not particularly limited, but ■ Method of mixing each raw material simultaneously ■ Modified polypropylene 8 and unmodified polypropylene B, which are hanging components, are mixed in advance as a master batch, and the remaining components are mixed together as a master batch. There are two methods: (2) carrying out a modification reaction of polypropylene in the first stage of the extruder, and mixing by adding the remaining components in the second stage. In this case, the extruder should be one with two or more raw material inputs, or one extruder with one T extruder connected in series. A modification reaction can be carried out, and a mixed reaction can be carried out using two units [1]. The mixing temperature is 170 to 250°C and the mixing time is 1 to 10 minutes. This reaction reduces the unreacted monomer to 0.1-1% and 0.05-0.2% (based on the composition) of the amount before mixing.

H. Other additives that can be mixed into the undeveloped IJ composition: Examples of such additives include known antioxidants, ultraviolet absorbers, nucleating agents, fillers, and pigments.

The mixing method and mixer are the same as for ordinary polypropylene compositions. The addition time of such an additive is preferably 1/1 mel during the polypropylene modification reaction, or 1-1° during the subsequent mixing reaction (note: 1: above).

9 Characteristic Effects of the Present Invention: The adhesive properties of the present invention are far superior to known adhesive polyolefin compositions when applied to polyolefin molded products in general, as well as metal, wood, paper, and other synthetic resin molded products. Shows excellent adhesion.

This will be explained below using Examples and Comparative Examples on the raw material manufacturing side.

Adhesiveness tests in Examples were conducted using the following method. Place a 0.4 mm thick sample sheet I in a 0.2 m true thickness aluminum board that has been cleaned with trichlorethylene.
After preheating at 0°C for 5 minutes, 1l at the same temperature with 209≦
I) Pressure bond for a period of time. 25+u+l! ] X 200
- A cut out of the old test J1 was subjected to a peel test.

The peel test is too°! II Ugly Strength (JIS K8115
4-1973 +++ basis), a pulling speed of 50 strokes, and a constant stroke of 1111 degrees were carried out at 23-Ce.

Raw material production example 1 Melt flow rate 0.5 (g/10IIlin) 100 heavy liquid parts of a propylene-ethylene block copolymer with an ethylene component content of 8%, 1 part by weight of maleic anhydride, and 2.5 parts by weight of dimethyl-2, 5-di(t-butylperoxy)
0.1 ii portions of hexane were blended for 3 minutes using a Henschel mixer (trade name). This raw material is 30m φ2
The mixture was melt mixed and reacted at 200°C in a vented shaft extruder, and extruded into strands, which were cut to obtain pellets. The pellets had 0.45% maleic anhydride grafted onto the polypropylene and contained 0.2% unreacted maleic anhydride.

Harao! I Production Example 2 Propylene homopolymer with melt flow rate 0.5 (g/l0m1n) 100 yen 1 part, anhydrous malein rrI
Part of Jl European vinegar and 0.11 parts of dicumyl peroxide were blended for 3 minutes in a Henschel mixer. Konohara 7
The stones were melt-kneaded and reacted at 200°C in a 30s*φ2 Joben I extruder, extruded into strands, and cut into pellets (11). This pen1/n, 1.
0.35% maleic anhydride is grafted onto polypropylene, and 0.3% of unreacted maleic anhydride is grafted onto polypropylene.
It contained.

Raw material production example 3 After dissolving the modified polypropylene pellets obtained in raw material production example 1 in hot xylene, reprecipitation in a large amount of acetone,
A finely powdered modified polypropylene was obtained, and the unreacted maleic anhydride contained therein was extracted and removed with /Se1. The unreacted maleic anhydride content in the modified polypropylene after extraction is 0.
．． 001ij i) It was 96 or less.

Raw Material Production Example 4 The modified polypropylene pellet obtained in Raw Material Production Example 2 was treated in the same manner as in Reference Example 3 to extract and remove unreacted maleic anhydride. The content of unreacted maleic anhydride in the modified polypropylene after extraction is 0. QQIQ? It was less than 1%.

Example 1. Comparative Example 1 In Production Example 1, blue maleic anhydride modified polypropylene 30Q'j%%, melt flow rate unmodified polypropylene (Tisso Polypropylene 7011) 50@φ%
and styrene-butadiene block copolymer, (S
BR) Ethylene-propylene Jt, ffi composite rubber (EPR), ethylene-propylene-norbornenehal composite rubber (EPPH3 or low density polyethylene (L
OPE) mixed with 20% by weight of 40p+mφ
The mixture was melted and mixed in an extruder at 220°C and pelletized. These pellets were formed into a sheet having a size of 0.411+1J'X by hot pressing, and the sheet was subjected to the above-mentioned adhesion test.

In addition, as Comparative Example 1, -1- modified polypropylene 50r
rui-% and a sheet having a composition of unmodified polypropylene of 50% by weight (Comparative Example 1-1) and the raw material used in Example 1? Tests were also carried out in the same manner using the modified polypropylene of Raw Material Production Example 3 instead of the maleic anhydride-modified polypropylene of J Production Example 1 (Comparative Examples 1-2 to 1-5).

These results are shown in Table 1.

Table 1 Example 2, Comparative Example 2.3 The modified polypropylene 1/ton in Example 1 was
Instead of the one obtained in Preparation Example 2, we used polypropylene with a melt flow rate of 1 (Tisso Polypropylene 7011) which was milled as unmodified polypropylene (Tisso Polypropylene 7011).Example 2) Tests were conducted in the same manner as in Example 1 and Comparative Example 1, except that the modified polyprolene obtained in Raw Material Production Example 4 was used in place of the modified polyprolene in Comparative Example (Comparative Example 2). In addition, a test was conducted in which the modified polypropylene of Raw Material Preparation Examples 1 and 2 was used alone (Comparative Example 3). These results are shown in Table 2.

Table 2

Claims (3)

[Claims] (1) For crystalline polypropylene L/7A modified by graft polymerization of one or more compounds selected from unsaturated carboxylic acids or their anhydrides and unmodified crystalline polypropylene B An adhesive polypropylene composition comprising one or more polymers selected from , ethylene polymer C, and styrene copolymer C. (2) The modified polypropylene A has a grafting ratio of unsaturated carboxylic acid or its anhydride of 0.1 to 4%, and the free state of the unsaturated carboxylic acid or its anhydride is 0.1 to 1%. Special B using a material containing % by weight
'rThe composition according to claim (1). (3) One or two selected from ethylene polymer C and styrene copolymer for modified polypropylene A and unmodified polypropylene B. The composition according to claim (1), wherein the above compound is dissolved at 170 to 250°C.