JPS62212447A - Bondable polypropylene composition - Google Patents

Abstract

PURPOSE:To obtain a polypropylene compsn. having improved adhesion to saponified EVA, by blending a specified modified polypropylene or a mixture thereof with polypropylene with a rubber material and a hydroxide of Mg or Ca. CONSTITUTION:A compsn. is obtd. by blending 58-89.95wt% modified poly propylene (A) obtd. by grafting at least one compd. selected from among unsatu rated carboxylic acids or anhydrides thereof or polypropylene (A) obtd. by mixing said modified polypropylene with 40-10wt% rubber material (B) and 2.0-0.05wt% magnesium or calcium hydroxide (C). The amount of the carboxylic acid or anhydride to be used for said graft reaction is 0.01-5.0wt% based on the entire amount of the compsn. As the rubber material, ethylene/ propylene rubber and an ethylene/propylene terpolymer are preferred from the viewpoints of softening effect and compatibility with polypropylene.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Technology] The present invention relates to adhesive polypropylene compositions, and more specifically, the present invention relates to adhesive polypropylene compositions, and more specifically, a modified polypropylene obtained by grafting an unsaturated carboxylic acid or its anhydride with a rubber substance and magnesium or calcium. The present invention relates to an adhesive polypropylene composition that has significantly improved adhesion to a saponified ethylene-vinyl acetate copolymer and is blended with a hydroxide.

[Conventional technology]

A laminate of saponified ethylene vinyl acetate copolymer and polypropylene overcomes the shortcomings of polypropylene sheets, such as the lack of gas barrier properties and oil resistance, and the shortcomings of saponified ethylene vinyl acetate copolymer, which is water absorption. In recent years, it has begun to be used as a new composite material for packaging materials and containers for foods, medicines, etc., to compensate for its shortcomings.

However, polyolefins such as polypropylene and polyethylene are non-polar polymeric compounds, so while they are chemically stable and have various excellent properties, they have no affinity with polar compounds and are ethylene-vinyl acetate copolymer. It was difficult to adhere to the combined saponified material. For this reason, modified polyolefins obtained by grafting unsaturated carboxylic acid and other polar monomers onto polyolefins are well known as adhesive polyolefins, which improve the adhesion of polyolefins to saponified ethylene-vinyl acetate copolymers. Many methods have been proposed.

For example, ■ A method of mixing a rubber substance with a modified polyolefin obtained by grafting unsaturated carboxylic acids onto a polyolefin (#Publication No. 54-40112, JP-A No. 52-2854)
8) , ■ A method of mixing a thermoplastic polyester with a modified polyolefin that has been subjected to a graft reaction with unsaturated carboxylic acids (JP 52-14683), ■ A method of mixing amorphous polypropylene with a modified polypropylene that has undergone a graft reaction with an unsaturated carboxylic acid. Addition method (Japanese Patent Application Laid-Open No. 54-9034
8) etc. have been proposed.

However, both methods have the effect of increasing adhesive strength when the adhesive polyolefin and saponified ethylene copolymer are in contact with each other in a molten state for a long time, but molding with a short adhesion time such as coextrusion molding In the case of this method, there is a problem that the adhesive force is insufficient and the adhesive is easily peeled off after cooling and solidifying.

In addition, for the purpose of improving adhesion to metals, there is a method of adding magnesium oxide to a polyolefin prepared by grafting unsaturated carboxylic acids (Japanese Patent Publication No. 51-48195), and a method previously reported by the present inventors of unsaturated carboxylic acid. A method of adding magnesium or calcium hydroxide to polypropylene graft-reacted with acids (JP-A-59-2
15349) and the like have been proposed, but both methods have excellent effects when adhering to metals, but hardly any improvement in adhesion is achieved when adhering to saponified ethylene-vinyl acetate copolymers.

[Purpose of the invention]

The present inventors have made extensive studies on improving the adhesion of modified polypropylene in which a saponified ethylene-vinyl acetate copolymer and an unsaturated carboxylic acid are graft-reacted in a laminate manufacturing method such as a coextrusion method. As a result, when polypropylene modified by grafting an unsaturated carboxylic acid or its anhydride is coexisting with both a rubber substance and magnesium or calcium hydroxide in a certain range, ethylene-vinyl acetate copolymerization is possible. It was discovered that the adhesion with coalescence was significantly improved, and the present invention was completed. Rubber substances or calcium or magnesium hydroxides alone.

Although the adhesion with saponified ethylene-vinyl acetate copolymer is hardly improved, it is surprising that the adhesion is significantly improved when both substances coexist in a certain range of amounts.

As is clear from the above description, the purpose of the present invention is to produce ethylene-vinyl acetate copolymer that can be used even in molding methods that require relatively short adhesion time, such as coextrusion molding, compared to conventional unsaturated carboxylic acid-modified polypropylene. An object of the present invention is to provide a polypropylene composition that easily adheres to chemical compounds and has strong adhesive properties.

[Structure and effects of the invention]

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

(1) Modified polypropylene obtained by grafting one or more compounds selected from unsaturated carboxylic acids or their anhydrides, or polypropylene mixed with the modified polypropylene (A) 58-
8i 9.95% by weight, 40 to 10% by weight of rubber substance (B), and magnesium or calcium hydroxide (C
) An adhesive polypropylene composition containing 2.0 to 0.05% by weight.

(2) The amount of unsaturated carboxylic acid or its anhydride used in the grafting reaction is 0.01 to 5% relative to the entire composition.
．． The adhesive polypropylene composition according to item (1) above, which has a content of 0% by weight.

The structure and effects of the present invention will be explained in detail below.

A0 Variant +'1 River polypropylene (A) used in the present invention
: In Mizuhiki, propylene homopolymer, propylene-ethylene block or random copolymer with a propylene polymer portion content of 50% by weight or more, propylene-ethylene-butene-1 block or random copolymer, and propylene-butene-1 block or random copolymer 1 random copolymer with a melt flow rate (hereinafter referred to as MFR) of 0.01 to
50 (g/10 minutes) preferably o, i to 10 (g/10
minutes).

Unsaturated carboxylic acids and their anhydrides used in the present invention: The carboxylic acids include maleic acid, acrylic acid, methacrylic acid, fumaric acid, itaconic acid, citraconic acid, crotonic acid, incrotonic acid, mesaconic acid and Examples of the anhydride include maleic anhydride, angelic acid, etc.
Examples include citraconic anhydride and itaconic anhydride. Among them, maleic anhydride is easy to use and provides preferable results.

The amount used is 0.01 per adhesive polypropylene composition.
-5.0% by weight, preferably 0.01-2.0% by weight. If the amount used is less than 5.0% by weight, the adhesive force of the adhesive polypropylene composition will be insufficient.
The degree of improvement in adhesion is small even when the temperature is exceeded, and the amount of unreacted unsaturated carboxylic acid and its anhydride remaining in the modified polypropylene increases, resulting in a worsening of the hue of the product when molded into sheets, films, etc. This causes disadvantages such as the formation of bubbles and bubbles. Examples of graft reaction methods include melt-kneading the polyolefin, grafted polymer, and catalyst in an extruder, and methods in which the grafted polymer and catalyst are mixed with polypropylene suspended or dissolved in an appropriate solvent. There is a method of adding and heating and stirring. Among these, one preferred embodiment of the graft reaction is a method in which 0.01 to 0.51 % of organic peroxide based on polypropylene is added to the polypropylene and grafted material mixture, and the mixture is melt-kneaded at 170 to 250°C using an extruder. can be given.

As the organic peroxide, one having a decomposition temperature of 170 to 250°C, preferably one having a half-life temperature of 1 minute to 130 to 200°C can be used.
．． 5-dimethyl(t-butylperoxy)hexane, 1
．． 3-bis(t-butylperoxy)hexane, 1,3
Examples include -bis(t-butylperoxyisopropyl)benzene, dicumyl peroxide, penzoyl peroxide, and the like. If the amount of organic peroxide added is less than 0.01% by weight, the effect of the addition is insufficient, and if it exceeds 5% by weight, the polypropylene will decompose, the MFR will increase abnormally, and the physical properties of the modified polypropylene will be impaired. This causes a decrease in adhesion.

The modified polypropylene thus obtained is used alone or in combination with unmodified polypropylene. In the case of mixed use, the proportion of modified polypropylene used is 1% by weight or more, preferably 10% by weight or more, particularly preferably 30% by weight or more, based on the total amount of one composition.

Rubber substance (B) used in the present invention: These can be added during the modification of polypropylene, ■ added to modified polypropylene and melt-mixed, or ■ added during melt-mixed modified polypropylene and unmodified polypropylene. Although any of the above methods may be used, it is best to use methods (1) and (2) in combination to improve adhesion and improve the MFR of the composition.
These usage amounts, which are preferable from the point of view of control, are:
The amount is 10 to 40% by weight, preferably 10 to 30% by weight, based on the total amount of the composition. If the amount used is less than 10% by weight, the effect of improving adhesion is insufficient, and if it exceeds 40% by weight, the properties of the polypropylene resin will not only be impaired, but the adhesive strength will also be reduced. It is also possible to replace less than 10% by weight (based on the composition) of the rubber with a significant amount of other soft resins (eg, low density polyethylene, EVA or atactic polypropylene).

Rubber materials used in the present invention include, for example, ethylene propylene rubber, ethylene-propylene terpolymer, butadiene rubber, styrene-butadiene rubber, ethylene-butadiene rubber, polyptadiene rubber, ethylene-propylene rubber,
1-butene rubber, chloroprene-based synthetic rubber, urethane rubber, silicone rubber, acrylic rubber, acrylonitrile-butadiene rubber, chlorinated polyethylene, natural rubber, etc. Among them, ethylene-propylene rubber and ethylene-propylene rubber.
The use of propylene terpolymer has a softening effect,
It is also preferred from the point of view of compatibility with polypropylene.

20 Magnesium or calcium hydroxide used in the present invention: These are in the form of fine powder. ■ Method of adding during modification of polypropylene, ■ Method of adding during melt mixing of modified polypropylene and rubber substance, ■ Method of adding during melt mixing of modified polypropylene. , and a method of adding it during melt mixing of unmodified polypropylene and a rubber substance, and any of the above methods can be used. However, method (2) is preferred from the viewpoint of improving adhesiveness.

The amount used is 0.05 to 2.0% by weight based on the total amount of the composition.
and preferably 0.05 to 1.0% by weight.

If the amount used is less than 0.05% by weight, the effect of improving adhesion is insufficient, and even if it exceeds 2.0i 1%, the degree of improvement in adhesive strength is small, and even decreases.

Furthermore, when formed into a sheet, film, etc., there are drawbacks such as foaming due to moisture absorption.

Other additives that can be mixed into the E, Wood 5F, and Light compositions: Such additives include known antioxidants, ultraviolet absorbers,
These include antistatic agents, nucleating agents, colorants, and lubricants. The mixing method and mixing amount are the same as for ordinary polypropylene compositions.

The timing to add these additives is before the grafting reaction,
It may be added either during or after the reaction, but it is preferable to add additives that have an adverse effect on the grafting reaction or are likely to be altered by the grafting reaction after the reaction.

C6 Characteristic effects of the composition of the present invention: Compared to conventional unsaturated carboxylic acid-modified polypropylene, the adhesive polypropylene composition of the present invention can be used with ethylene vinyl acetate even when molding methods such as coextrusion that require relatively short adhesion time are used. Easily adheres to saponified copolymers and has strong adhesion.

The present invention will be explained in detail below using examples.

Adhesiveness tests in Examples were conducted using the following method.

Using a multi-layer sheet molding machine, the saponified ethylene-acetic acid vinyl copolymer layer (80%)/adhesive polypropylene layer (
A multilayer sheet consisting of a saponified layer of ethylene-vinyl acetate copolymer (80 IL) was coextruded.

This multi-layer sheet was cut lengthwise to a size of 25cm-width x 170mm, and the 180 degree peel strength (pulling speed 200mm/
sin, measurement temperature 23°C).

The saponified ethylene vinyl acetate copolymer used was
Eval EP-F 10IA manufactured by Kuraray ■, and the extrusion temperatures during coextrusion were 240℃ for adhesive polypropylene and 23℃ for saponified ethylene vinyl acetate copolymer.
It was extruded at 0°C.

Raw material production example 1 MFRl, 8 (g/10 min) Ethylene component content 4.
0% by weight propylene-ethylene random copolymer 99
．． 42% by weight, 0.5% by weight of maleic anhydride and 1.
0.08% by weight of 3-bis(t-butylperoxyisopropyl)benzene was blended for 3 minutes using a Henschel mixer (trade name). This raw material was melt-kneaded and reacted at 200° C. using a 45*mφ two-wheel vent extruder, and the extruded strands were cut to obtain pellets. The pellets were grafted with 0.24% by weight maleic anhydride.

Raw material production example 2 NFRo, 5 (8710
min) The same procedure as in Raw Material Production Example 1 was conducted except that a propylene-ethylene block copolymer having an ethylene component content of 8% by weight was used. The pellet was grafted with 0.27i% maleic anhydride.

Raw material production example 3 MFRo, 5 (g/10
The same procedure as in Raw Materials Production Example 1 was conducted except that the propylene homopolymer of 1) was used. The pellets were grafted with 0.19% by weight maleic anhydride.

Raw material production example 4 MFRl, 8 (g/10 min) propylene-ethylene random co-T5 combination 89 with ethylene component content 4% by weight
．． 42% by weight, maleic anhydride 0.5% by weight, 1.3-
Bis(t-butylperoxyisopropyl)benzene 0
．． 0Ejl1%i and 10% by weight of ethylene propylene rubber (EPO2P) manufactured by Nihon Gosei Rubber ■ were blended for 3 minutes using a Henschel mixer. This raw material is 45mmφ2
Melt-knead and react at 200°C in a vented shaft extruder,
The extruded strands were cut to obtain pellets. The pellets were grafted with 0.29% by weight maleic anhydride.

Raw material production example 5 The amount of modified polypropylene added was 79.422I! 1
% and the amount of ethylene-propylene rubber added was 200% by weight. The pellet was grafted with 0.3iIn 1% maleic anhydride.

Raw material production example 6 MFRl, 8 (g/10 min) Ethylene component content 4.
0% by weight propylene-ethylene random copolymerization 79
．． 67 tons! □, )%, maleic anhydride 0.2%, 1
, 3-bis(t-butylperoxyisopropyl)benzene o, o3 ton tr%, 11 synthetic Gofu ethylene-propylene rubber (EPO2P) 20ffi% and magnesium hydroxide Q, 1iji% in a Henschel mixer. and blended for 3 minutes. This raw material is 455mφ2
The mixture was melt-kneaded and reacted at 200° C. using a vented shaft extruder, and extruded into strands, which were cut to obtain pellets. This pellet was grafted with 0.18i% maleic anhydride.

Example 1 Anhydrous maleic modified polypropylene 3 obtained in Raw Material Production Example 1
Unmodified ethylene-propylene random copolymer with 6% by weight, MFRl, 8 (g/10 min), 43.9% by weight.

20% by weight of ethylene propylene rubber, 0.1% of magnesium hydroxide (hereinafter sometimes abbreviated as Mg(OH)z)
% by weight and 2 in a 45mm diameter twin screw vent extruder.
The mixture was melt-kneaded and pelletized at 30°C. This pellet was coextruded with a saponified ethylene-vinyl acetate copolymer, and the adhesion test described above was conducted.

Example 2 Raw material as modified polypropylene Maleic anhydride modified polypropylene of Production Example 2, M as unmodified polypropylene
The same procedure as in Example 1 was conducted except that an ethylene-propylene copolymer of FRo, 5 (g/10 min) was used.

Example 3 Raw material as modified polypropylene Maleic anhydride modified polypropylene of Production Example 3, M as unmodified polypropylene
The same procedure as in Example 1 was carried out except that a propylene homopolymer of FRo, 5 (g/10 min) was used.

Comparative Example 1 Using 84% by weight of unmodified polypropylene, ethylene-
The same procedure as in Example 1 was carried out except that propylene rubber and magnesium hydroxide were not added.

Comparative Example 2 The same procedure as in Example 1 was conducted except that 44% by weight of unmodified polypropylene was used and no magnesium hydroxide was added.

Comparative Example 3 The same procedure as in Example 1 was carried out except that 83.8% by weight of unmodified polypropylene was used and ethylene-propylene rubber was not added.

These results are shown in Table 1.As is clear from Table 1,
When either ethylene-propylene rubber or magnesium hydroxide is used alone in a mixture of modified polypropylene and unmodified polypropylene, the adhesive strength of the resulting composition is comparable to that of modified polypropylene alone. It can be seen that the effect of improving adhesion is poor, and that the effect of improving adhesion can only be obtained when both ethylene-propylene rubber and magnesium hydroxide are used.

Table 1 $l Ethylene-propylene rubber is Japan Synthetic Rubber II
! l EP02P Examples 4-8. Comparative Example 4.5 To determine the required amount of ethylene-propylene rubber,
As shown in Table 2, the amount of ethylene-propylene rubber added was varied (0, 5, 10, 20°30, 40.50% by weight), and 36% by weight of the maleic anhydride-modified polypropylene of Raw Material Production Example 1, MFRl , 8 (g/10 min) unmodified ethylene-propylene random copolymer 83.9-1
A mixture of 3.9% FFI (Examples 4 to 10) and 0.1% magnesium hydroxide was melted and kneaded at 230°C in a 45mm x φ twin-screw vented extruder and pelletized. This pellet was coextruded with a saponified ethylene-vinyl acetate copolymer, and the adhesion test described above was conducted.

These results are shown in Table 2.

Table 2 Ethylene-propylene rubber is manufactured by Japan Synthetic Rubber ■99
EP02P Examples 9 to 13, Comparative Example 6.7 In order to determine the required amount of magnesium hydroxide, the amount of magnesium hydroxide added was varied as shown in Table 3 (
0,0,01,0,05,0,1,0,5゜1.0.2
．． 0% by weight), maleic anhydride modified polypropylene of Raw Material Production Example 1 38% by weight, MFRl, 8 (g/10 min) unmodified ethylene-propylene random copolymer 44
~42@% by weight (Examples 11 to 17) and ethylene-propylene rubber (EPO2P manufactured by Japan Synthetic Rubber ■) 20!
% II was mixed, and the mixture was melt-kneaded and pelletized at 230°C in a 45ssφ twin-screw vent extruder. This pellet is coextruded with saponified ethylene vinyl acetate copolymer,
The adhesion test described above was conducted.

These results are shown in Table 3.

Table 3 Examples 14 to 16, Comparative Example 8.9 Unmodified ethylene-propylene random copolymer of maleic anhydride modified polypropylene obtained in Raw Material Production Example 1 361i%, NFRl, 8 (g/10 min) 43.9 heavily%,
20% by weight of ethylene-propylene rubber and 0.1% by weight of various metal compounds were mixed, melt-kneaded and pelletized at 230°C in a 45m x 2 vented extruder. The pellets were coextruded with a saponified product of ethylene-vinyl acetate and the adhesion test described above was conducted.

The results are shown in Table 4.

Example 17 Raw materials: 36% by weight of the maleic anhydride-modified polypropylene obtained in Production Example 4, 43.911% of unmodified ethylene-propylene random copolymer with MFRl, 8 (g/10 min),
18.4 slI sewing% of ethylene-propylene rubber and 0.11% of magnesium hydroxide were mixed, and 45 m
The mixture was melt-kneaded and pelletized at 230° C. using a φ twin-screw vent extruder. This pellet was coextruded with a saponified ethylene-vinyl acetate copolymer, and the adhesion test described above was conducted.

Example 18 The same procedure as in Example 17 was carried out, except that the maleic anhydride-modified polypropylene of Raw Material Production Example 5 was used as the modified polypropylene, and the amount of ethylene-propylene rubber added was 12.8%.

Comparative Example 10 The same procedure as in Example 17 was conducted except that the maleic anhydride-modified polypropylene of Raw Material Production Example 1 was used as the modified polypropylene and no ethylene-propylene rubber was added.

Example 19 The same procedure as in Example 17 was carried out, except that the maleic anhydride-modified polypropylene of Raw Material Production Example 1 was used as the modified polypropylene, and the ethylene-propylene rubber was 20% by weight.

Comparative Example 11 The maleic anhydride-modified polypropylene obtained in Raw Material Production Example 6 and the saponified ethylene-vinyl acetate copolymer were coextruded, and the adhesion test described above was conducted.

These results are shown in Table 5.

Table 5 21 Ethylene-propylene rubber is manufactured by Romoto Synthetic Rubber ■ EPO2P 2 Anhydrous maleic resistant F0.2wtL
Kg (OH) 20.1wt$ Oyo Kankae 20wtX Modified Product Examples 20, 21. Comparative Example 12.13 38% by weight of maleic anhydride-modified polypropylene obtained in Raw Materials Production Example 1, 43.8% by weight of unmodified ethylene-propylene random copolymer with MFRl, 8 (g/10 min),
Mix 0.1% by weight of water-ugly magnesium and 20% by weight of various resins, and use a 45mmφ twin-screw vent extruder 2
The mixture was melt-kneaded and pelletized at 30°C. This pellet was coextruded with a saponified ethylene-vinyl acetate copolymer, and the adhesion test described above was conducted.

These results are shown in Table 6.

Claims (3)

[Claims] (1) Modified polypropylene obtained by grafting one or more compounds selected from unsaturated carboxylic acids or their anhydrides, or polypropylene mixed with the modified polypropylene (A) 58-8
9.95% by weight, 40-10% by weight of rubber substance (B), and hydroxide of magnesium or calcium (C) 2
．． An adhesive polypropylene composition containing 0 to 0.05% by weight. (2) The amount of unsaturated carboxylic acid or its anhydride used in the grafting reaction is 0.01 to 5% relative to the entire composition.
．． 0% by weight of the adhesive polypropylene composition according to claim (1). (3) The adhesive polypropylene composition according to claim (1), wherein the rubber substance (B) is ethylene-propylene rubber or ethylene-propylene polymer.