US 4,232,086 AGranted

Polyolefin-metal bonded structures and process for preparing same

AssigneeToyo Seikan Kaisha, Ltd.

InventorsFumio Mori, Isao Ichinose, Go Kunimoto

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Abstract

When a polyolefin layer is bonded to a metal substrate through a primer layer, if a polar group-containing ethylenically unsaturated monomer-modified olefin resin (A) having a specific polar group concentration and a specific degree of crystallinity and a coating film-forming base resin (B) are incorporated at a specific ratio into a specific mixed solvent to form a paint and the primer layer is formed by using this paint, there is obtained a novel multi-layer distribution structure comprising the base resin distributed predominantly in the portion of the primer layer contiguous to the surface of the metal substrate and the modified olefin resin distributed predominantly in the portion of the primer layer contiguous to the polyolefin layer and having a concentration gradient of the two components (A) and (B) in the thickness direction. By virtue of the presence of this primer layer, the bonding strength between the metal substrate and the polyolefin and the corrosion resistance of the metal substrate as well as the processability of the polyolefin-metal bonded structure are substantially improved.

Claims17

Dependent claims

A polyolefin-metal bonded structure comprising a metal substrate and a polyolefin resin layer bonded to the metal substrate through a primer layer, said primer layer comprising:

(a) a polar group-containing ethylenically unsaturated monomer-modified olefin resin (A) containing said polar groups at a concentration of between about 0.01 and 200 milliequivalents per 100 g of the olefin resin and having a degree of crystallinity of at least about 50%;
and
(b) a coating film-forming base resin (B) at an (A)/(B) weight ratio of between about 0.2/99.8 and 40/60,
said primer layer having a multi-layer distribution structure with concentration gradients of components (A) and (B) in the thickness direction such that the base resin (B) is distributed predominantly in the portion of the primer layer contiguous to the surface of the metal substrate and the modified olefin resin (A) is distributed predominantly in the portion of the primer layer contiguous to the polyolefin layer, wherein when said primer layer is divided into three sub-layers with respect to the thickness direction, the distribution ratio, Dx, defined by the following formula:
D.sub.x =10000 W.sub.X /(W)(C.sub.A)
wherein W is the weight of the primer layer per unit surface area (mg/dm.sup.2), C.sub.A is the average % by weight of the modified olefin resin in the primer layer, and W.sub.X is the weight per unit area (mg/dm.sup.2) of the modified olefin resin in each sub-layer, being at least about 50% in the sub-layer, L.sub.S, contiguous to the polyolefin layer and not higher than about 10% in the sub-layer, L.sub.B, contiguous to the surface of the metal substrate.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 05/960,931Filed 15 Nov 1978
Priority: JP 5213725912 Nov 1977
Granted: 4 Nov 1980
Term ends: Not estimatedThe source records don’t support an estimate.

Classification18 codes

B32B 15/085
Of synthetic resin: comprising polyolefins
B32B 7/12
Interconnection of layers: using interposed adhesives or interposed materials with bonding properties
B32B 15/08
Comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material: of synthetic resin
B32B 27/32
Layered products comprising a layer of synthetic resin: comprising polyolefins