JPS6038445A - Resin composition - Google Patents

Abstract

PURPOSE:A resin composition which exhibits strong adhesiveness over a wide temperature range when applied to metal, wood, paper, or polyolefin, prepared by mixing a polyvinyl acetal resin with a polyolefin resin. CONSTITUTION:5-98wt% polyvinyl acetal resin (e.g., polyvinyl butyral resin of an average degree of polymerization of about 300-5,000 and a degree of acetalization of about 50-88mol%) is mixed, by heating to about 190-300 deg.C, with 95-2wt% polyolefin resin (e.g., maleic acid-modified polyethylene of a maleic acid component content of about 300-10,000ppm). If required, a plasticizer (e.g., dibutyl phthalate) may be added in an amount of 50wt% or below, based on the polyvinyl acetal resin.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition. More specifically, the present invention relates to a resin composition suitable for use as an adhesive for metals, wooden boards, paper, polyolefins, etc., and which has excellent gas barrier properties when used as a film. Resin #IIJy passed through adhesive in the past.

Currently, various products have been developed, each with their own advantages and disadvantages, and are used depending on the purpose.

The inventors of the present invention have arrived at the resin composition of the present invention as a result of extensive studies aimed at obtaining an adhesive that has adhesive strength at relatively low temperatures and also has adhesive strength over a wide temperature range.

That is, the gist of the present invention is that the (A) component is a polyvinyl acecool resin of 5 to 9 g weight, the (B) component is a polyolefin resin of 2 to 935% jf (%), and optionally (C) the plasticizer is a component. The resin composition contains the agent in an amount of !iOM or less based on component (A).

(It is well known that components 711, such as polyvinyl formal resin and polyvinyl butyral 4i1J311r, are used as components of adhesives for metals, but these have strong crosslinking properties, so if they are used alone in a heating bath, Due to its crosslinking properties, it is not possible to create an adhesive layer or melt it in a heating bath and use it for two innings by extrusion molding or the like.

For this reason, these resins are generally used after being dissolved in a solvent. In some cases, a plasticizer is added to the large needle to prevent crosslinking and used in a molten state, but generally, if a large amount of plasticizer is sieved, the plasticizer will be added to the adhesive surface, that is, the interface between the metal etc. and the resin. It bleeds and causes a decrease in adhesive strength over time. Furthermore, for example, polyvinyl acetal resin does not have any adhesive strength relative to polyolefin resin, and is therefore unsuitable as an adhesive for bonding metal and polyolefin.

Component (B), the polyolefin, has adhesive properties to polyolefins if it is itself a polyolefin. Modified polyolefins in particular are one of the seven adhesives that are useful as adhesives for metals and polyolefin resins, and can be used to bind molten resins.
Although it is particularly effective when bonding, it has the disadvantage that the second inning temperature is relatively high and the object to be bonded must be preheated to a temperature close to the melting temperature of the modified polyolefin. 2) In order to lower the lining temperature, it has been considered to control the crystallinity of the resin, and although this can lower the lining temperature to some extent, it has the disadvantage that the adhesive strength decreases when the laminate is exposed to high temperatures. have The present inventors investigated the development of a more effective adhesive and found that a composition containing a polyvinyl acetal resin as component (A) and a polyolefin resin as component (B), and in some cases a plasticizer, was found to be relatively effective. The present invention was achieved by discovering that it is effective as an adhesive that is heated and melted at a low temperature.

The reason why the composition of the present invention is suitable as an adhesive used by heating and melting at a relatively low temperature is thought to be that in the composition of the present invention, the polyvinyl formal resin does not cause crosslinking even when heated and melted. It will be done. Although the reason for this is not clear, it is thought that S<lyolefin prevents the polyvinyl formal resin from crosslinking.

Such a phenomenon, that is, the phenomenon that polyolefin reduces the crosslinking of polyvinyl formal, was unexpected and has great industrial benefits.

Component (4) used in the present invention, that is, polyvinyl acetal resin, is generally obtained by polymerizing vinyl acetate monomer,
It is produced by producing polyvinyl acetate resin and then reacting polyvinyl alcohol obtained by saponification with an aldehyde. That is, polyvinyl acetal resin is a resin having vinyl acetal blue, vinyl alcohol blue, or vinyl acetate groups, and the reaction product with formaldehyde is called polyvinyl formal resin, and the reaction product with butyraldehyde is called polyvinyl butyral resin. Examples of the melivinyl acecool resin include polyvinyl butyral, polyvinyl formal, polyvinyl acetoacecool, polyvinyl propyl acetal, etc. Among them, polyvinyl butyral resin is preferably used.

Furthermore, polyvinyl acetal resins containing carboxyl groups are also preferably used.

The carboxyl group is 0.0% in the polyvinyl acetal resin. /
~S malt, preferably Ol, about 2 to 3 moles of summer is desirable. A polyvinyl acecool resin containing a carboxyl group can be obtained, for example, by reacting a copolymer of vinyl acetate and an unsaturated carboxylic acid with an aldehyde containing a carboxyl group during acetalization.

The average degree of polymerization of the polyvinyl acecool resin used in the present invention is not particularly limited, but is preferably in the range of 300 to s, o oo, and particularly preferably SOθ or more. Further, the degree of acetalization is preferably about go-gg malt.

Polyolefins in unexploded ψJ include Migo, q
High, medium and low density polyethylene, polypropylene homopolymer or propylene-based random or block copolymer, ethylene-vinyl acetate, and ethylene-vinyl acetate are excluded. Used alone or in combination.

A modified polyolefin is suitably used as the polyolefin of the present invention, and the modified polyolefin resin is prepared by mixing the above-mentioned polyolefin with an ethylenically unsaturated carboxylic acid such as maleic acid or acrylic acid or an acid anhydride thereof (hereinafter referred to as (sometimes referred to as a "modifier") through a graft reaction.

To blend a modified polyolefin with a polyvinyl acetal resin, the modified polyolefin may be blended as is, but it is desirable to blend the modified polyolefin with an unmodified polyolefin and then blend this with the polyvinyl acetal resin.

The blending ratio of the modified polyolefin and the unmodified polyolefin is preferably such that the combined amount of the modified polyolefin is 20 parts by weight or more, with the combined HU ratio of the two being the /θθ overlapped portion.

The number of modifiers contained in modified polyolefins or blends of modified polyolefins and unmodified polyolefins is 3.
00~/θ, OθθPE”spreferably!r Oq
~7,000 pI) m''C is desirable.

If it is less than J 00 ppm, the adhesive force will be poor; θ
If it exceeds Oθppm, gel-like substances, color development, etc. will occur, which is not preferable.

The composition ratio of polyvinyl acetal (component (A)) and polyolefin (component (B)) is: (A) component A - 9g% by weight, (B) component? S--Can be blended arbitrarily within the range of weight %.

If the amount of component (A) is less than 5M, the adhesion temperature cannot be expected to decrease. If the Ir content is more than % by weight, there will be a problem in the contact force at high temperatures and the adhesion to polyolefin will be poor.

Furthermore, the composition of the present invention has good gas barrier properties and can be used for films etc. that require gas barrier properties. In particular, compositions containing these components are preferred for gas barrier properties.

If component (B) exceeds 30% by weight, the gas barrier properties will be poor.

Furthermore, a plasticizer can be added in an amount of 0% by weight or less based on component (4). Generally, adding a plasticizer is effective in lowering the bonding temperature.

However, if it exceeds SO%, the adhesive force will decrease, which is not preferable.

Examples of plasticizers include phthalic acid esters such as dibutyl phthalate and dioctyl phthalate, phosphoric acid esters such as tri- and cresyl phosphate, fatty acid esters such as dibutyl sebacate, dicoethyl hexyl adipate, and dibutyl succinate, or triethylene glycol dibutyl esters. Glycol-conducting conductors such as chloride and the like are generally used, and any one of these can be selected. It is also possible to add inlar to improve adhesion.
Examples include calcium carbonate, Merck, mica, carbon graphite, and carbon black.

The amount of fins to be added is the total g of component (A) and component (B).
[The amount is about 10 to 100 parts by weight, preferably about 0 to 10 parts by weight, based on the weight part of Bi2O.

The above components may be mixed by heating under general conditions using a mixing and dispersing machine such as a ribbon blender, Banbury mixer, Niegoo mixer, Henschel mixer, roll, single screw, or twin screw extruder.

The heating temperature varies depending on the melting point of the resin used, but is usually 90-30°C, preferably 20-2s.
A temperature of about o'r3 is used.

The composition of the present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to the following Examples unless the gist thereof is exceeded.

In the Examples and Comparative Examples, the peel strength was measured using a tensile tester manufactured by Toyo Baldwin Co., Ltd. at a tensile speed of 10 ran/m.

In addition, the 1111I constant of oxygen gas permeability is AST month-D-/
It was measured in accordance with Da3t.

Example-7 Component (A) = polyvinyl butyneol with an M content of 10 kO and a phthyralization g/%.

(B) Component: Melt Index (MI) (ASTMD
/:13g-! ;'Measured by IT) 2.72710 minutes, medium density polyethylene 10 with density O0 3/y/crl
0.36 parts by weight of maleisic anhydride (modifier) and 0.0.2 parts by weight of α-α-bistercial butylperoxy-paradiisoglobilbenzene were added to 0 parts by weight, and the caliber was 3 omynφ.
Using a single screw extruder with L/D, 211, die temperature e, 21
01. MI 7 obtained by melt extrusion at screw rotation speed k Orpm
．． 2 F/10 minutes, reward agent Grand Ki 3 II 00
ppm modified polyethylene.

(A) Ingredients! 55 parts by weight (B) 02 parts and (C
3% by weight of gecoethylhexyl adipate as a component (plasticizer) was mixed for 10 minutes using a ribbon blur/goo (10 h/batch).

Next, we used a coaxial extruder with a diameter of 30 mm (Kyoi Tekko, PCM 3).
0-2! An adhesive composition was obtained by melt-kneading and pelletizing in an extruder under conditions of a die temperature λlθC and a screw rotation speed -0θrpm (coaxial rotation).

Using a co-layer T-die equipped with a diameter of 30 mmφ extruder and an SS ■φ extruder, the composition obtained above was transferred from the extruder with S5 mm diameter to a co-layer T-die with a die temperature of 2°C. Create a bath melting sheet and heat it to a predetermined temperature (Table-/)
30tanX/30LrrvnX controlled to
One layer of the molten sheet was placed on a 3" mm hot-rolled steel plate so that the surface of the composition was in contact with the sheet, and the sheet was degassed and bonded using a roll to obtain a laminate.

The thickness of the sheet was 10 θμ for the above-mentioned composition sheet and 36 mm for the outer polyethylene layer.

A test piece was cut out from the laminate at 2'OtZ' and used as a test sample to measure the peel strength at 2'OtZ'.

The results are shown in Table-/.

Example-U Example-/'t' Amount of (A) component tON used and (
B) A laminate of steel plate-adhesive layer-polyethylene was prepared in the same manner as in Example-/ by thoroughly mixing the modified polyethylene JON resin used in Example-/ as a component, and measuring the peel strength as shown in the table-/. Summary of 0 tables - / v, 6M7 Pa lecture.

Comparative Example-/Example-/Component (A) used in Example-/! r! A laminate of steel plate-adhesive layer-polyethylene was prepared in the same manner as in Example 1-/, except that a composition consisting of M Toribe and 3 parts by weight of a plasticizer was used as the adhesive layer, and the peel strength was determined.

The results are shown in Table-C.

Comparative Example - An example - A laminate of steel plate - adhesive layer - polyethylene was prepared in the same manner as in Example 7, except that only the component (B) used in Example 1 was used as the adhesive layer, and the peel strength was determined. . View results
Shown in 1.

Example-3 7 to 7% by weight of component (4) used in Example-/, and (E
Example 1 except that a blend of modified Borie Telefugu O used in Example 1 and 30 weight 51% unmodified polyethylene was used as the component, and 3 weight % dioctyl quilate was used as the plasticizer. A copper plate-adhesive layer-polyethylene laminate was prepared in the same manner as above, and its peel strength was measured. The results are shown in Table-C.

In Table 1 Comparison 1-1j-/, there was no adhesive force between the adhesive layer and the polyethylene lso, and peeling occurred at the interface between the two, while in Comparative Example-C and Example-3, peeling occurred between the copper plate and the adhesive layer. are doing.

Comparative Example - λ shows high contact force on the still temperature side/'IOC, but lacks adhesive force at low temperatures such as 13θC.

EXAMPLE The pellet of the adhesive composition used in Example 1 was formed into a film having a thickness of 100 μm using an inflation device. Separately, a sheet with a thickness of ta was manufactured from the unmodified polyethylene used in Example-7. A film made of an adhesive composition and a 7-t made of unmodified polyethylene were placed on a steel plate and pressed together at /gOC. The three were well bonded.

Example 5 (A) Component polyvinyl butyral resin with a double diameter of 61 degrees and a degree of butyralization of 70 degrees.

Component (B): Modified low-density polyethylene with density θ, Deco/f/7, MI/, 99//θ, grafted with maleic anhydride at θ6.2.

(C) Component (plasticizer) nidibutyl adibate.

(A) Ingredient zasM firefly, (B) Ingredient 10 layers, (C
) Component 5 heavy chain chains were thoroughly mixed and melted at θoC using a single-phase extruder with tθ extinguisher ψ to form pellets. A blown film having a thickness of SOμ was formed using the same pellet. The film was a clear, colorless, gel-free film. The oxygen gas permeability using the same film is summarized in Table 3.

Comparative Example 3 A film was prepared in the same manner using only the modified low density polyethylene used in Example 1, and the oxygen gas permeability was measured.
It was summarized in 3.

Comparative Example - Polyvinyl butyral resin used in Example - R! r
parts by weight and 3 parts by weight of plasticizer were mixed well and formed into pellets in the same manner as in Example. The beret had a yellowish tinge, which was thought to be caused by a change in resin.

A complete blown film was made using the pellet, but there was a lot of gel and holes were formed in the film around the gel part, making it impossible to make a uniform film.

Example-6 Polymerization [/ / 00, polyvinyl butyral resin with a degree of butyralization gO%, density θ, 1 bow, polyethylene resin with a melt index of 7.3, 6% by weight of dioctyl 7-talate as a plasticizer The mixture was thoroughly mixed and formed into a pelletized film in the same manner as in Example G. The oxygen gas permeability was summarized in Table 3.

Table-3

Claims (6)

[Claims] (1) Polyvinyl acetal resin 3 as component (A)
A resin composition comprising ~9g wt% by weight, 2 to 95% by weight of a polyolefin resin as the (B) component, and optionally further containing a plasticizer as a (C) component in an SO weight% or less based on the (A) component. . (2) The resin composition according to claim 1, wherein the polyvinyl acecool resin is polyvinyl butyral resin. (3) Is the polyolefin resin a homopolymer of ethylene or propylene, a copolymer of ethylene or propylene with other α-olenoin having 7θ or less carbon atoms, or a mixture thereof with a density of 0, g g to 0,9'? f/c
I/r Terror %#'fM yx o range The resin composition according to item 1 or 2. (4) Claims 1 to 3, wherein the polyolefin resin is a modified polyolefin modified with an α,β unsaturated carboxylic acid or its acid anhydride, or a blend of a modified polyolefin and an unmodified polyolefin. The resin composition according to any one of the above. (5) α for modified polyolefins or blends of modified polyolefins and unmodified polyolefins. β-unsaturated carboxylic acid or its acid anhydride from 30θ to 10,
The resin composition according to claim 9, containing 000 ppm. (6) (4) Is the component 70-9? Weight%, component (B) is 3
~ 30% by weight of heavy weight (C) Contains 50% by weight or less based on the plasticizer gold (A) component as tri component
A resin composition according to claims 7 to 5.