JPS62158035A - Laminate of wood and aluminum - 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] [Industrial application field] The present invention relates to a laminate of wood and aluminum.

More specifically, the present invention relates to a laminate of wood and aluminum having excellent interlayer adhesion, with an ethylene-vinyl acetate copolymer layer and a polyolefin resin layer interposed between the wood and aluminum.

[Prior art]

Conventionally, laminates of wood and aluminum have been used as building materials such as door materials and wall materials. The laminate may be an ethylene-vinyl acetate copolymer having a vinyl acetate content/θ weight t% or more, or a laminate containing a tackifier such as renicumaron, indene, coumarone-indene, rosin, or aromatic petroleum resin. A layer interposed between wood and aluminum is known.

[Problem that the invention seeks to solve]

However, the above-mentioned laminate has a problem in that the adhesion between the adhesive layer and aluminum is insufficient, and the aluminum surface peels off during long-term use.

[Means for solving problems]

In view of the above-mentioned prior art, the present inventors have conducted intensive studies to improve the interlayer adhesion of a laminate of wood and aluminum. The present invention was completed based on the discovery that a laminate of wood and aluminum with significantly improved interlayer adhesion can be obtained by interposing an olefin resin layer.

That is, the gist of the present invention is to provide a laminate including wood, an adhesive layer, and aluminum, in which the adhesive layer contains an ethylene-vinyl acetate copolymer layer having a vinyl acetate content of Z- or more by weight, and a polyolefin resin containing an unsaturated carboxyl group. The ethylene-vinyl acetate copolymer layer is laminated on the wood surface, and the modified polyolefin resin layer is laminated on the aluminum surface. The fI# layer body of wood and aluminum is characterized by being made of aluminum.

The present invention will be explained in more detail below.

In the present invention, the ethylene-vinyl acetate copolymer is a vinyl acetate-containing copolymer produced by a high-pressure polymerization method under 10θ0 to 3000 atmospheres, or a solution or emulsion polymerization method under 100-9100 atmospheres. fkj weight t% or more,
Preferably ljj~20% by weight, more preferably /θ~t
ito thunder scene and melt index (ASTMD
-7,23? ! 7T) is 0. /~sθ0? /10
minutes, preferably 1 to /Of / /0 minutes. If the vinyl acetate content is less than 5% by weight, the adhesiveness will be insufficient, which is not preferable.

In the present invention, the above ethylene-vinyl acetate copolymer may be used alone or an adhesion improver may be added thereto at 7 to 2 parts by weight per 100 parts by weight of the ethylene-vinyl acetate copolymer.
You may use it by blending 0 parts by weight. Examples of the adhesion modifier include low molecular weight terpene resins, coumaron resins, coumaron-indene resins, rosins, xylene resins, petroleum resins, and low polymerization degree polyolefins having a molecular weight of less than *2000, preferably less than /θθθ.

Next, the modified polyolefin resin used in the present invention is a polyolefin resin in which a monomer or polymer of an unsaturated carboxylic acid or anhydride thereof is chemically bonded to the polyolefin resin.
It is a grafted material in which the amount of bonding is 0.02 to 0.02% to the polyolefin resin in terms of monomer of unsaturated carboxylic acid or its anhydride. If the bond amount is less than 0.02 weight, the adhesive strength will be low, and if it is more than 7.0 weight, the smelly gel-like substance will increase, which is not preferable. Within this range, θ is preferably 0.2 to
O1j heavy weight, the most preferred weight is 0.03-0.3% by weight
It is.

Polyolefin resins used as raw materials in the present invention include high density polyethylene, low density polyethylene, medium density polyethylene, linear low density polyethylene, ethylene-
Propylene copolymer, ethylene-butene/copolymer,
Examples include polypropylene, propylene-butene/copolymer, polybutene/, polycoumethylpentene/, and ethylene-vinyl acetate copolymer.

Particularly preferred is low-density polyethylene with a density of 00/10 to θ and 3sf/all.

On the other hand, as the unsaturated carposidic acid or its anhydride to be grafted, acrylic acid, maleic acid, itaconic acid, fumaric acid, hymic acid, cytodiconic acid, or anhydride thereof is used.

In particular, it is preferable to use maleic anhydride.

The modified polyolefin resin of the present invention can be produced by adding an unsaturated carboxylic acid or anhydride thereof to a polyolefin resin and causing a graft reaction according to a known method. The process for causing the graft polymerization reaction may be a solution method or a slurry method, but from the viewpoint of cost, a melt mixing method is preferable. In the case of the melt mixing method, the polyolefin resin is mixed with 0.0 λ to 0% by weight of an unsaturated carboxylic acid or its anhydride and 0.0% by weight. /weight%
If an organic peroxide of preferably 0.00/~θ, Oj weight is blended and melt-kneaded at /20°C to 200°C, the grafting efficiency will be high, there will be no fish eyes or gel-like substances, and the color will be improved. This is advantageous because a good, odor-free modified polyolefin is obtained.

To further explain the above melt-kneading method, if the amount of unsaturated carboxylic acid or its anhydride blended into the polyolefin resin is less than 0.02w/i1H%, the adhesive strength will be low.
0 heavy N 4 or more is not preferable because it produces a smelly gel-like substance. Among the above ranges, 0.102 to 0.5% by weight is preferred, and 0.03 to 0.3% by weight is most preferred. If the amount of organic peroxide used exceeds 0,7z, the rate will decrease, such as an increase in gel-like substances and fisheye in the film, and a large decrease in molecular weight, and a decrease in adhesive strength or unreacted monomers will be peroxide, acetyl peroxide, di-t-butyl peroxide, -t
-Butyl peroxylaurate, dicumyl peroxide, α
, α'-bis-t-butylperoxy-p-diisopropylbenzene, Jj dimethyl-2, j-di-t-butylperoxyhexane, -butylperoxybenzoate, n-butyl-4t, %-bis-t- Butyl peroxyvalate, octanoyl peroxide, λ, j dimethylco,! Examples include -di(benzoylveroxine)hexane, vinyltris(1-butylperoxy)silane, methylvinyl(cumylperoxy)silane, etc.In the melt mixing method, unsaturated carboxylic acid or its Either an anhydride and, if necessary, an organic peroxide are tri-blended at a predetermined mixing ratio in a Henschel mixer, or an unsaturated carboxylic acid or its anhydride, and an organic peroxide, if necessary, are dissolved in an organic solvent to form a polyolefin. It is injected into a resin powder or pellet, and further blended using a Henschel mixer, etc. In the present invention, since the unsaturated carboxylic acid or its anhydride as a graft monomer is used in a smaller amount than in the conventional method, it is mixed into a polyolefin resin. When kneading, it is preferable to use an organic solvent as described above to ensure uniform mixing. Examples of such organic solvents include acetone, methyl ethyl ketone,
Examples include cyclohexanone. The blended polyolefin resin powder or pellets is put into a kneading machine whose system is purged with nitrogen gas, such as a Banbury mixer, a double screw mixer, an extruder, etc., and the temperature is 72°C.
Melt kneading is carried out at 0 to 300°C for 0.1 to 30 minutes. ?
! ! If the opening time during kneading is less than 20°C, the graft reaction described later becomes difficult to occur, and if it exceeds 300°C, thermal deterioration of the polyolefin resin becomes noticeable, which is not preferable.

Therefore, in the present invention, the polyolefin resin is subjected to a graft reaction with an unsaturated carboxylic acid or its anhydride by the above melt kneading, and in the resulting modified polyolefin resin, the organic compound used as the initiator of the graft reaction is The peroxide is completely decomposed and the unsaturated carboxylic acid or its anhydride is almost chemically bonded to the polyolefin resin.

Next, the wood used in the present invention includes softwood, hardwood, and plywood thereof. These pieces of wood may have any shape such as a sheet or a plate.

On the other hand, the aluminum laminated with these woods may be an alloy with other metals, and its shape may be sheet-like,
It may have any shape such as a plate shape. Further, by forming a film on the surface of aluminum using, for example, tetrahydric acid, phosphoric acid, or further anodic oxidation, the adhesive strength can be further increased, so it is desirable to carry out this treatment in advance.

In the present invention, the laminate composed of wood, an ethylene-vinyl acetate copolymer layer, a modified polyethylene resin layer, and aluminum is a pre-formed ethylene-vinyl acetate copolymer film or sheet and a modified polyolefin resin film or sheet. A method in which a two-layer film or sheet obtained by coextruding an ethylene-vinyl acetate copolymer and a modified olefin resin in advance is laminated onto aluminum using a polyolefin resin film or sheet. A method of extrusion laminating a sheet, extrusion laminating an ethylene-vinyl acetate copolymer film or sheet extruded in a separate extruder on the modified polyolefin resin layer, and laminating wood by thermocompression bonding. . Thermocompression bonding is usually /10-260℃, preferably lλO~aOO
Temperature in °C, /~! O word/-1 preferably j~30 Jc
Pressing is carried out at a pressure of f/- for 7 seconds to 70 minutes, preferably for 7 to 5 minutes. In addition, in the laminate of the present invention, by interposing an unmodified polyolefin resin layer between the ethylene-vinyl acetate copolymer layer and the modified polyolefin resin layer, the cost of the contact layer can be reduced without reducing adhesiveness. It is preferable because it can be measured. Unmodified polyolefin resins include high-density polyethylene, low-density polyethylene, medium-density polyethylene, linear low-density polyethylene, ethylene-
Propylene copolymer, ethylene-butene/copolymer,
Examples include polypropylene, propylene-butene/copolymer, polybutene/, polytermethylpentene/, and ethylene-vinyl acetate copolymer. Especially the density O,
Low-density polyethylene of 10S-θ and isf/crll is preferred.

Furthermore, the laminate of the present invention is not limited to a three-layer laminate made of aluminum (hereinafter abbreviated as A), a resin layer (hereinafter abbreviated as B), and wood (hereinafter abbreviated as C). , A/B/C/B/A.

It may be a multilayer laminate such as A/B/O/B/C.

Although the thickness of the laminate of the present invention varies depending on its use, it usually has a thickness of aluminum layer/-20 θμ, modified polyolefin resin layer 5 to θθμ, and ethylene-vinyl acetate copolymer layer 5 to . The range is 200μ and the wood layer/~-〇〇m.

Since the laminate obtained by the present invention has excellent interlayer adhesion, it is suitable for use as building materials such as door materials and wall materials.

〔Example/〕

High-pressure low-density polyethylene (density 20, 20f/C)
y/l, melt index (hereinafter abbreviated as M) degree: 0
．． ri/l/d, M engineering: Cof/10 min, maleic anhydride containing Jl:/-2θOppm) (!: Ethylene-vinyl acetate copolymer (vinyl acetate content t:/!wt%, M engineering: , 2 t / / 0 min, density: 0,93 t /
d) and a composition in which coumaron having a molecular fi 2 r 00 and 10% by weight of an indene resin were added at the resin temperature it.

The modified high-pressure polyethylene layer was mixed with 70% by weight of coumaron-indene resin into the θμ ethylene vinyl acetate copolymer by coextrusion in a die using inflation at ℃.
A 20μ composite film was produced.

Next, the aluminum plate (0.2 liao thick) was brought into contact with the modified polyethylene veneer surface of the composite film, and the veneer plywood (!-Jun) was heated at θ℃, 3 minutes, λOkg/-. Pressed.

After the obtained laminate was installed at Hiroo O℃/year, the peel strength was measured using a tensilon type tensile tester, but no deterioration over time was observed, and the peel strength between ht/modified PO was J-kf//2! It was found that cohesive failure occurred between the ethylene-vinyl acetate copolymer and coumaron-indene mixture/veneer.

[Example λ]

High-pressure low-density polyethylene (density: O, octopus θt/c!
I, melt index (hereinafter abbreviated as M):
Modified high-pressure polyethylene ■ (density: θ, ri/2/
7, "M", 29/10 minutes, maleic anhydride content: /
, 2θOppm) and ethylene-vinyl acetate copolymer■
(Vinyl acetate content: 75% by weight, M process: 2t/10min, density 20, ri 32/m) with a composition containing 10 weight percent of Kumaronken indene resin with a molecular weight of 2s00 and high-pressure low-density polyethylene◎ (density = 0.2209/crI%M work:, 2r/10 min) was co-extruded in a die using inflation at resin temperature/gθ℃.■10μ/◎10μ/
A three-dimensional composite of ■/θμ was manufactured.

Next, the modified polyethylene layer of the composite film was brought into contact with the aluminum surface, and the ethylene-vinyl acetate copolymer coumaron/indene resin mixed layer was brought into contact with the veneer surface, and aluminum ram board (θ, 71 mm thick) and veneer plywood ( Heat pressing was carried out under the conditions of 5 ha thickness) and /hiro θ°C for 3 minutes and 20 to 9/(-d().

After the obtained laminate was installed at 0℃/year, the peel strength was measured using a tensilon type tensile tester, but no decrease was observed over time, and the peel strength between ht and modified PO was s kg/2 jtan.
It was found that the bond between ethylene vinyl acetate copolymer and coumaron/indene mixture/veneer caused cohesive failure.

[Comparative example/]

High-pressure low-density polyethylene [density: 0.9-0? /a/
I, M I: 7 t// 0 minutes at resin temperature 300
℃ laminated.

Next, place the laminate between the pinch-type roll heaters so that the high-pressure polyethylene surface of the laminate and the veneer plywood are in contact with each other.
Heat pressing was performed under the conditions of 0°C/θky/cm″/sec.

After 7 days of pressing, the resulting laminate was separated between plywood/resin and kl.
/ Adhesive strength between resins is /9/2! It peeled off easily when it was less than m.

〔Effect of the invention〕

The laminate of the present invention has aluminum firmly attached to the surface of the wood.
It is laminated with excellent stability over time and can be used very suitably as a construction material such as a door material, wall material, etc.

Applicant Mitsubishi Chemical Industries, Ltd. Agent Patent Attorney Hase - (and 7 others) Procedural Ner. %" should be corrected to "4 vehicle volume%."

(2) In the 13th line of page 4, the statement "5% by weight" is corrected to "quadruple boxed %."

(3) On page 9, line 14, [Kneading time, 1 is corrected to read "mixing temperature."

that's all

Claims (1)

[Claims] (1) In a laminate composed of wood, a resin layer, and aluminum, the resin layer has a vinyl acetate content of 4% by weight.
Add 0.0 of an unsaturated carboxylic acid or its anhydride to the above ethylene-vinyl acetate copolymer layer and polyolefin resin.
It consists of a modified polyolefin resin layer grafted with 2 to 1.0% by weight, and is characterized in that the ethylene-vinyl acetate copolymer layer is laminated on the wood surface, and the modified polyolefin resin layer is laminated on the aluminum surface. A laminate of wood and aluminum.