JPS5867446A - Manufacture of laminate - 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 The present invention relates to a method for producing a laminate comprising a polypropylene resin and a metal.

Laminates of synthetic resins and metals are widely used, taking advantage of their respective characteristics. For example, by coating the surface of a metal molded article with a synthetic resin thin film, metal corrosion and second rust can be prevented. In addition, metal sandwich panels, which have a synthetic resin sheet between two metal thin films, have a metal surface, are as light as a synthetic resin, and have far superior mechanical properties and properties compared to molded products made of synthetic resin alone. It has heat resistance, and can be used as, for example, automobile parts to reduce weight and cost. Polypropylene has the lowest specific gravity among synthetic resins, has excellent mechanical properties such as rigidity and heat resistance, and is inexpensive, so it is especially popular in recent years due to the weight reduction and low price of automobiles. There is a strong demand for this material, and studies are underway to use it as an intermediate layer resin for metal sandwich panels.

However, since polypropylene is nonpolar, it exhibits almost no adhesion to metals, and until then, it is not possible to obtain a laminate that firmly adheres to metals. Conventionally, to improve adhesion, corona discharge treatment and chromic acid treatment were applied to polypropylene and (t) metal surfaces.

A method of applying surface treatment such as flame treatment or etching; (2) A method of using a modified polyolefin in which anhydrous male and 41 are grafted onto a polyolefin (for example, Japanese Patent Publication No. 42-107
No. 57, Oka No. 47-4822), ■ A method using a composition in which an acid-modified polyolefin is blended with a hydrocarbon-based synthetic elastomer or an ethylene polymer (for example, JP-A No. 52-80)
No. 554, I'ff No. 155-21850), etc. are known. However, when the temperature exceeds the melting point of polypropylene, the polypropylene/Kinyo laminate produced by these methods easily deforms due to its own weight or external force, resulting in a problem of poor heat resistance at 46 temperatures.

It is generally well known that by crosslinking polymeric substances, melt deformation resistance and high temperature heat resistance are greatly improved. However, polypropylene is a thermally decomposable polymer, and when mixed with an organic peroxide and heated, crosslinking does not occur, but on the contrary, it decomposes and its viscosity decreases.

Therefore, in order to thermally crosslink polypropylene, a method has been adopted in which a crosslinking aid such as divinylbenzene or liquid 1,2 polybutadiene is mixed with a radical generator and heated.

However, the crosslinked propylene obtained in this way not only does not adhere to metal at all, but it is extremely difficult to form it into films, sheets, etc., and it is difficult to use it to manufacture laminates with metal. Almost impossible.

The inventors of the present invention have conducted intensive studies on a method for producing a polypropylene/metal laminate with good high-temperature resistance, and have developed the present invention by using a specified organic peroxide on modified polypropylene and press-bonding it under specific conditions. Reached. That is, the present invention uses polypropylene, unsaturated carboxylic acids, a crosslinking aid, and a one-minute drop temperature that is 10% lower than that of bulk polypropylene.
A composition consisting of an organic peroxide with a temperature higher than ℃ and a metal,
A polypropylene system characterized in that the polypropylene is pressed at a temperature higher than the melting point of the polypropylene and lower than the 1-minute half-loss temperature of the organic peroxide, and then heated to a temperature higher than the 1-minute half-loss temperature of the organic peroxide. This is a method for manufacturing a laminate including a resin layer and a metal layer. 19. According to the present invention, the polypropylene composition is formed into, for example, a film or sheet (hereinafter collectively referred to as a sheet) at a temperature lower than the 1 minute half-life temperature of the organic peroxide, and then the metal and the organic peroxide are formed. Also provided is a method for producing a laminate comprising a polypropylene resin layer and a gold maple layer, which are pressed together at a temperature equal to or higher than the one-minute decay temperature of the oxide.

The polypropylene used in the present invention is not particularly limited, and includes homopolypropylene and propylene-ethylene block copolymer.

Propylene-ethylene random copolymer, copolymer of propylene and α-olefin,! ? and mixtures thereof. Propylene-ethylene random copolymers and propylene-ethylene block copolymers are preferably used for these 5%. The melting point of these polypropylenes varies depending on the tacticity and comonomer content, but is generally in the range H of 130 to 170C.

Examples of the unsaturated carboxylic acids used in the present invention include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, and acid anhydrides thereof.

Esters, amides, imides, metal salts, etc., such as maleic anhydride and citraconic anhydride.

Itaconic anhydride, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, glycidyl acrylate, dalicidyl methacrylate, monoethyl maleate, diethyl maleate, monomethyl fumarate ester, dimethyl fumarate, itaconate monomethyl ester, itaconate diethyl ester, acrylamide.

Methacrylamide, maleic acid monoamide.

Maleic acid diamide, maleic acid-M-E noethylamide, maleic acid-181g-diethylamide, maleic acid-N-monobutylamide.

Maleic acid-N, N-dibutylamide, fumaric acid monoamide, fumaric acid diamide, fumaric acid-N-monoethylamide, fumar 11-M#) I-diethylamide, 7malic acid-N-motuptylamide, nomalic acid-N, N-dibutylamide.

Maleimide, N-butylmaleimide, N-phenylmaleimide, sodium acrylate.

Specific examples include sodium methacrylate, potassium acrylate, and potassium methacrylate. Among these, maleic anhydride and metal salts of unsaturated carboxylic acids are preferably used. The amount of unsaturated carboxylic acids used is not particularly limited, but in order to obtain a laminate with good adhesiveness, it is generally 0.01 to 20 parts by weight, preferably 11.1 to 11 parts by weight, per 11 parts of polypropylene 100.
It is necessary to add 0 parts by weight.

The crosslinking aid used in the present invention is a compound having a double bond of 2 WA or more in one molecule, and has a number average molecular weight of 500 to 500, for example, containing divinylbenzene, diallyl phthalate, triallyl glycerate, and diene monomer as main components. IQ
OOO liquid rubber, such as 1,2-polybutadiene.

1.4-polybutadiene, styrene-butadiene copolymer, acrylonitrile-butadiene copolymer, or carboxyl group, hydroxyl group, mercapto group in the molecule,
halogen atom.

1,2-polybutadiene, 1,4-polybutadiene, polyimprene, polychloroprene, 1,2-polypentadiene, styrene-butadiene copolymer, acrylonitrile-containing functional groups such as amino groups, aziridino groups, and epoxy groups. Examples include butadiene copolymers, butadiene-imprene copolymers, butadiene-pentadiene copolymers, divinylbenzene and liquid 1.
2-polybutadiene is preferably used. The amount of crosslinking aid added is 1 to 5 parts by weight per 100 parts by weight of polypropylene.
0 parts by weight, preferably 6 to 30 parts by weight per 100 parts by weight of polypropylene.

When the amount of the crosslinking aid added is less than 1 part by weight, the effect of improving high temperature heat resistance is small, and when it is added to 50 parts by weight, the rigidity below the melting point of the modified polypropylene is significantly lowered, which is undesirable.

In the present invention, the organic peroxide has a half-lifetime per minute (m degrees).
Use a material whose ai degree at which it decomposes by half in 1 minute) is at least 10°C higher than the melting point of polypropylene (the peak degree of the endothermic curve measured at a heating rate of 10°C/min with a differential scanning calorimetry needle). is necessary. The melting point of polypropylene is 130~
170 tl: (7) An organic peroxide having a hot water temperature of 0-t' and a 1-minute half-reduction in knitting density of 140° C. or higher is generally used. Hk of such organic peroxides, 2, 4.
4-)! j Methylbenzene 2-hydroperoxide, diimpropylbenzene hydroperoxide,
Cumene hydroperoxide, t-butyl hydroperoxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)-hext
1,3-bis-(1-butylperoxy-isopropyl)-benzene, t-butylcumyl peroxide.

Di-t-butyl peroxide, 2,5-dimethyl-2
,5-di(t-butylperoxy)-hexyne-5,
1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane, 1,1-di-t-butylperoxycyclohexane, 2,2-di(1-butylperoxy)-butane, 4 .4-di-t-butylperoxyparelic acid-n-butyl ester, di-t-butylperoxy-hexahydroterephthalate, di-t-butylperoxy-hexahydroterephthalate
-butylperoxyazelate, t-butylperoxy-3,5,5-)limethyl hequinoate, t-butylperoxyacetate, t-butylperoxybenzoate, t-butylperoxyimprobyl carbonate,
t-Cucinic Acid Peroxide, Vinyl Tris-
(t-butylperoxy)silane. The amount of organic peroxide added varies depending on the amount of crosslinking aid added, but is generally 0.1 to 1 part by weight per 100 parts by weight of polypropylene.
0 parts by weight is desirable.

If the amount of organic peroxide added is less than 0.1 part by weight, the crosslinking length will be low, and if it exceeds 10 parts by weight, decomposition will occur and the effect of improving high temperature heat resistance will be small, which is not preferable. Also, 8 to be used normally if necessary! Polymeric substances other than polypropylene, inorganic and organic fillers, heat stabilizers, and weather stabilizers.

It is also possible to mix lubricants, antistatic agents, nucleating agents, pigments, dyes, flame retardants, antiblocking agents, and the like.

The present invention relates to the above-mentioned polypropylene, unsaturated cardanic acids, crosslinking aid, and organic peroxide.

Depending on the case, other polymeric substances other than polypropylene, fillers, and other additives may be mixed. Mixing is carried out using a tumbler blender, a V-type flender, a Henschel mixer, a ribbon mixer, or the like. Sometimes these mixtures are put in a screw extruder.

It is also possible to melt and knead the polypropylene at a temperature higher than the melting point of polypropylene and lower than the one-minute half-life temperature of the organic peroxide using a mixing roll, a Banbury mixer, or the like.

In the present invention, in order to laminate the polypropylene composition and the metal with good adhesion, it is important to press the polypropylene composition at a temperature higher than the melting point of the polypropylene and lower than the one-minute half-life temperature of the organic peroxide. Next, in the present invention, in order to impart high-temperature heat resistance to the press-bonded laminate, it is extremely important to heat it to a temperature equal to or higher than the one-minute half-life temperature of the organic peroxide.

The heating time varies depending on the decomposition temperature of the organic peroxide, but
Generally, 10 seconds to 30 minutes is appropriate. Although heating can be carried out by once cooling the laminate to room temperature and then reheating it, it is preferable to raise the temperature successively after the laminate thermocompression bonding.

Furthermore, the present invention involves forming the polypropylene composition into a sheet-like material in advance at a temperature lower than the 1-minute half-life temperature of the organic peroxide, and then forming the polypropylene composition into a sheet at a temperature higher than the 1-minute half-life temperature of the metal and organic peroxide. It is also possible to bond by thermocompression.

The metals used for lamination are particularly limited to iron, aluminum, chromium, and nickel.

Gold, silver, steel, magnesium, zinc, tin, lead.

Examples include steel, stainless steel, galvanized iron, and tinplate, with iron and aluminum being preferably used.

The polypropylene/metal laminate with one or more layers obtained as described above has strong adhesive strength between the two, excellent high-temperature heat resistance, and has both the excellent characteristics of polypropylene and the excellent characteristics of metal. Furthermore, it has excellent new features such as not having positive propylene or metals, so it can be effectively used as automobile materials, industrial materials, building materials, beverage cans, packaging materials for various foods, etc.

Examples of the laminate of the present invention are shown below, but the present invention is not limited thereto.

The adhesive strength and high temperature heat resistance of the laminates obtained in the examples were determined by the following methods.

The adhesive strength is 0.1■ between two 2-width metal sheets.
T of the three-layer laminate with a polypropylene composition layer of thickness
- Expressed in peel strength.

The measurements were carried out at 23° C. and 50% RH at a tensile rate of 20 μ/min.

High-temperature heat resistance was measured by placing a 6-layer laminate with a 0.1-inch thick polypropylene composition layer between two parallel metal sheets with an overlap length of 2 ys in an oven at 200°C. and hang one metal sheet with a wire.
After 10 minutes, apply a load of 200f to the lower metal sheet,
It is expressed as the time until both metal sheets separate. In addition,
The thickness of the metal sheet is 0.2 mm for the iron sheet and 0.1 mm for the aluminum sheet, and these are sufficiently degreased.

Example 1 MIF processing = 0.6 f/10 min, propylene-ethylene random copolymer with ethylene content of 3.0% (melting point: 140°C
) 100 parts by weight, 5 parts by weight of calcium methacrylate,
10 parts by weight of divinylbenzene, 2.0 parts by weight of dicumyl peroxide (1 minute half-life temperature 179°C), 0.1 part by weight of butylated hydroxytoluene, and 0.1 part by weight of carnoum stearate were mixed in a Henschel mixer for 5 minutes. The mixture was mixed and a 0.1-thick sheet was formed at 165C using an extruder with a T-die.

This sheet was sandwiched between 21-width aluminum sheets and pressed at a temperature of 170°C and a pressure of 10°C for 5 minutes, followed by heating at 220°C for 5 minutes. The adhesive strength of the laminate thus obtained [Fil 5.3 odor/23. High temperature heat resistance was 1 hour or more.

Comparative Example 1 The same procedure as in Example 1 was conducted except that benzoyl peroxide (1 minute half-life temperature: 130° C.) was used instead of dicumyl peroxide. In the case of sheet molding, the extrudate became flaky and no sheet could be obtained.

Comparative Example 2 The same procedure as in Example 1 was carried out except that the sheet extrusion temperature was changed to 2200.

The extrudate became flaky and no sheet was obtained.

Comparative Example 3 The same procedure as in Example 1 was conducted except that calcium methacrylate was not added. The adhesive strength of the obtained laminate was 0.

Comparative Example 4 The same procedure as in Example 1 was conducted except that divinylbenzene was not added. The adhesive strength of the resulting laminate was 1-111+/2cI11. High temperature heat resistance was 10 seconds or less.

Comparative Example 5 The same procedure as in Example 1 was carried out except that dicumyl peroxide was not added. The adhesive strength of the obtained laminate was 0.41/2 tx, and the high temperature resistance was 50
It was seconds.

Example 2 MFI=1-5F/10min, ethylene content 2.7wt
propylene-ethylene block copolymer (melting point 160
C) 100 parts by weight, 40 parts by weight of calcium carbonate having an average particle size of 1.2 μm, 0.5 parts by weight of anhydrous maleic #, and 20 parts by weight of liquid 1,2-polybutadiene having a number average molecular weight of 1000.

2.5-dimethyl-2,5-di(t-buty,rubaroxy)-hexyne-3 (1 minute half-life temperature 196°C) 3 parts by weight, butylated hydroxytoluene 0.1ijl 1 part,
0.11ii 1 part of calcium stearate was mixed for 5 minutes with a Henschel mixer, and then heated to 170°C with a CCM extruder.
Melt mixed wire pelletization was carried out. A 0.1-thick sheet was formed from the obtained polypropylene composition pellets at 175° C. using an extruder equipped with a T-die.

This sheet is sandwiched between 2oI1 width iron sheets220
℃ temperature and 10 Kt/cd pressure for 10 minutes.

The adhesive strength of the laminate thus obtained was 10.8
K4/2t:s, high temperature heat resistance was 1 hour or more.

Comparative Example 6 In Example 2, 2,5-dimethyl-2,5-di(
The same procedure as in Example 2 was carried out except that benzoyl peroxide was used in place of t-butylperoxy)-hexyne-3. When pelletizing using a CCM extruder, the extrudate became flaky and clean pellets could not be obtained.

Comparative Example 7 The same procedure as in Example 2 was carried out except that the sheet extrusion temperature was changed to 220°C. The extrudate became flaky and no sheet was obtained.

Comparative Example 8 The same procedure as in Example 2 was conducted except that maleic anhydride was not added.

The adhesive strength of the obtained laminate was 0.

Comparative Example 9 The same procedure as in Example 2 was conducted except that liquid 1,2-polybutadiene was not added. The adhesive strength of the obtained laminate was 5.5 Kt/21, and the high temperature heat resistance was 10 seconds or less.

Comparative Example 10 In Example 2, 2,5-dimethyl-2,5-
The same procedure as in Example 2 was carried out except that di(1-butylperoxy)-hexyne-3i was not added. The resulting laminate had an adhesive strength of α2h/2cs and a thermal property of 260 seconds.

patent applicant Tokuyama Soda Co., Ltd. □

Claims (1)

[Scope of Claims] (1) A composition consisting of polypropylene, unsaturated carboxylic acids, a crosslinking auxiliary agent, and an organic peroxide whose half-life in 1 minute (a) is 10° C. or more higher than the melting point of the polypropylene, and a metal; 1 of the organic peroxide wrinkled above the melting point of the polypropylene.
A method for producing a laminate consisting of a polypropylene resin layer and a metal layer (2), characterized in that the organic peroxide is pressed at a temperature lower than the half-life of 11 degrees per minute, and then heated to 11lf, which is the half-life of the organic peroxide in 1 minute of a degree or more. ) The manufacturing method according to claim S (e), in which the laminate comprises a metal layer/polypropylene resin layer/metal layer (3) The unsaturated carboxylic acid is maleic anhydride and the unsaturated carboxylic acid metal salt. Claim No. (1)
(4) The manufacturing method described in Claim (1), in which the crosslinking aid is liquid 1,2-polybutadiene or divinylbenzene. (5) The metal is iron or aluminum. Production method according to claim (1) (6) Production according to claim (1), in which the polypropylene composition is formed into a sheet shape at a low m degree using a one-minute half-life source of organic peroxide. Method