JPH0352980A - Adhesive for laminated product - Google Patents

Abstract

PURPOSE:To obtain the subject adhesive, composed of a copolymer of an unsaturated carboxylic acid and an alpha-olefin, a block copolymer of styrene and conjugated diene and polypropylene resin, having excellent adhesion, good in moldability, heat and oil resistance and useful for PS-based and PP resins. CONSTITUTION:The objective adhesive composed of (A) 5-80wt.% copolymer composed of an unsaturated carboxylic acid and/or unsaturated carboxylic acid ester and an alpha-olefin, (B) 10-80wt.% block copolymer of styrene and a conjugated diene (e.g. butadiene) or a hydrogenated copolymer thereof and (C) 10-40wt.% polypropylene resin.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an adhesive for a laminate of polystyrene (hereinafter abbreviated as PS) based resin and polypropylene (hereinafter abbreviated as PP) resin. [Prior Art] Sheet field In recent years, packaging materials for foods and molded materials for electrical products are required to have good shapeability, food safety, heat resistance, oil resistance, etc.Currently, in these sheet fields, PS resin is the most commonly used resin because it has excellent productivity, especially formability. However, PS resin has problems with heat resistance and oil resistance. On the other hand, PPl4 resin has excellent heat resistance and oil resistance. However, there is a problem in productivity. In order to take advantage of the characteristics of both, materials made by laminating PS resin and PP resin have good shapeability, heat resistance, and oil resistance, and are suitable for packaging materials and prestige materials. However, PS resin has poor affinity and adhesive properties with PP resin, and it is necessary to use an adhesive for lamination. Various methods have been proposed as adhesives for lamination. For example, JP-A No. 54-110285 discloses a method using a mixture of a styrene-butadiene copolymer and a polyolefin, and JP-A No. 62-57440 discloses a method using a block copolymer of a vinyl aromatic compound and a conjugated diene. Methods such as using a mixture of vinyl acetate copolymer and polyolefin are known, but none of them have sufficient adhesion, and the latter has insufficient thermal stability, causing burns and an acetic acid odor. It cannot be used for food applications. Therefore, there is no satisfactory laminate of PS resin/PP resin, and there is currently a need for a good adhesive. [Problems to be solved by the invention] The purpose of the present invention is to laminate PS resin and PP resin,
The objective is to provide an adhesive with thermal stability and sufficient strength. [Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors found that when producing a packaging or molding material by laminating PS resin and PP resin, adhesive As agents, unsaturated carboxylic acids and/or unsaturated carboxylic esters and α-
By using a copolymer consisting of olefin, styrene, a conjugated hydrogen block copolymer, and polypropylene, and especially by blending a limited amount of mJI, good heat resistance and sufficiently high adhesive strength can be obtained. It is possible to reuse product scraps, and there is less unevenness in wall thickness during secondary processing such as vacuum forming or pressure forming of sheets, and the defect rate of products is significantly reduced. reached. That is, the present invention provides (a) 5 to 80% by weight of a copolymer consisting of an unsaturated carboxylic acid and/or an unsaturated carboxylic acid ester and an α-olefin; (b) a copolymer of styrene and a conjugated diene or its water; This is an adhesive for a laminate of PS resin and PP resin, characterized by comprising 10 to 80% by weight of additives and (c) 10 to 40% by weight of polypropylene resin. Even if the component (a) used in the present invention is a random copolymer consisting of an unsaturated carboxylic acid and/or an unsaturated carboxylic acid ester and an α-olefin, the component (a) used in the present invention may be a graft copolymer of another monomer component to a polyolefin. It may be something that has been done. Furthermore, by adding polyolefin to these copolymers, α
- The amount of monomers other than olefins may be diluted to the desired amount. In the present invention, unsaturated carboxylic acids and/or unsaturated carboxylic esters include, for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. It will be done. Among these, ethyl acrylate is the most preferred. In the present invention, α-olefins include, for example, ethylene, propylene, l-butene, 4-methylpentene-■, and among these, ethylene is particularly preferred. The ratio of these monomer components is α-olefin 98 to 6
0%, unsaturated carboxylic acid and/or unsaturated carboxylic acid ester 40-2M amount2 is suitable, and this is determined depending on the purpose. The component (b) used in the present invention is a block copolymer of styrene and a conjugated compound such as butadiene or isobrene, or a hydrogenated product thereof, and the floc structure is a Goui block structure, a triblock structure, a radial block structure, etc. structure, multi-block structure, etc., and copolymers with any of these structures or hydrogenated products thereof may be used.
The proportion of styrene in the block copolymer is 10 to
Component (c) used in the present invention is suitably 80% by weight and is selected depending on the purpose and block structure. It is a copolymer. α-olefins include ethylene, 1-7'tene, 1-pentene, and -hexene. In the present invention, the blending ratio of (a) precept, (b) precept, and (c) is such that (a) precept is 5 to 80% in the adhesive.
%, (b) RFC portion is 10-80% (c) Precept is 10-80%
A range of 40% by weight is preferred.

More preferably, 30 to 60 fold'Iχ, 30 to 6
The range is 0 weight z and 10 to 30 weight itχ. If the amount of each compounded is outside this range, the adhesion with either the PS resin or the PP resin layer will decrease. If necessary, other resins may be added to the adhesive of the present invention within a range that does not reduce adhesiveness. In addition to the resin, necessary additives such as antioxidants, ultraviolet absorbers, pigments, dyes, fillers, nucleating agents, antiblocking agents, slip agents, and banding agents are added.
Appropriate amounts of antistatic agents, flame retardants, etc. may be added. The adhesive used in the present invention can be prepared by various known methods, such as mixing each component in a Linn blender, V-type blender, tumbler, Henschel mixer, etc. Methods include melting and kneading with rolls, kneaders, etc., or methods of dissolving each precept in a solvent, stirring well, and adding a poor solvent to precipitate. The PS resin to which the adhesive of the present invention is applied is a resin mainly composed of styrene, such as polystyrene, high-impact polystyrene, styrene-acrylonitrile copolymer, and ARS resin, and there are no other limitations. The PP resin to which the adhesive of the present invention is applied is not particularly limited, except that it is a polypropylene homopolymer or a copolymer of propylene and a small amount of other α-olefin, and known resins can be used for -a. can. As a method for manufacturing a product using the adhesive of the present invention, films and sheets of each of PS resin, PP resin, and adhesive are manufactured in advance, and then the adhesive is applied to a film or sheet of other resin. A method of sandwiching and thermocompression bonding, a method of extruding a molten adhesive onto a film or sheet of either PS resin or PP resin, and then superimposing a film or sheet of the other resin,
A method can be adopted in which PS resin, PP, and adhesive are melted in separate extruders and coextruded using a multilayered T-die or circular die to obtain films, sheets, vibrators, etc. It is also possible to form a multilayer parison and obtain a bottle by blow molding. The T-die method includes a manifold die method using a feed block and a multi-manifold die method, and either method may be used. The temperature when extruding PS resin or PP resin may be the conventional extrusion temperature, and the extrusion temperature of adhesive is usually 190 to 300.
``C1 is preferably 200 to 280°C.
There are various shapes of laminates to which the adhesive of the present invention can be applied, such as films, sheets, pipes, and bottles. It is also possible to manufacture various containers depending on the shape and other methods. [Example] The present invention will be explained below with reference to Examples. Adhesive strength is JI
It was determined according to SK-6854 (T-type peel test).
Melt index (old) is measured according to JIS K-7210, and below, the conditions of (190°C, 2.16 kg) are Ml(a) (200'C.5.0kg)
The conditions of (230°C and 2.16 kg) are abbreviated as old (b), and the conditions of (230°C and 2.16 kg) are abbreviated as M I (c). Example 1 Ethylene-ethyl acrylate copolymer' EEA61
70' (manufactured by Nippon Unicar ■, Ml(a) -6.
0, ethyl acrylate - 18.0 weight z) 10 weight z
1 Styrene-ptadiene block copolymer “Toughblen A”
' (manufactured by Asahi Kaei ■, Ml(a) - 2.6, styrene amount - 40 weight Ml(c)-1.5, Xchire 7-4
．． 0 weight fig) 35% was mixed in a tumbler and extruded using a 30m extruder to obtain adhesive pellets. The above adhesive and High Impact PS (old PS) 'Tobolex 830-05 (Mitsui Toatsu Chemical ■, Ml(b)-2
．． s) and PP homobolymer “Mitsui Noblen JS-
Using a total of three extruders, a feed block, and a T-die, a multilayer extruded sheet having the following configuration was manufactured using ``G'' (manufactured by Mitsui Toatsu Chemical Co., Ltd., Ml(c)-1.5).
The resin composition consisted of three types and three layers: PS/adhesive/PP, and the thickness of each layer was 0.3/0.03/0.3 nm. Each resin layer was extruded using a PS (upper side): 65an machine, an adhesive: a 30m machine, and a PP: 65mm.
In addition, the extrusion temperature was 230'C for each resin layer.
．． The adhesive had sufficient adhesive strength for both the PS and PP layers. Adhesive &lltc, adhesive strength Table-2
It is shown in Multilayer extrusion sheet, pp sheet and p sheet obtained in this example
Vacuum shape test was conducted using S sheet and compared.
The raw materials used in this example were used for the sheet and PS sheet. Measuring method A 900 x 90 h sheet material was set in a large vacuum forming machine, heated with a heater, and the appropriate time for vacuum forming and the drawdown distance at the center of the sheet at that time were measured. The measurement results are shown in Table 1. As shown in the results in Table 1, multi-layering had a significant effect on the drawdown performance of PP and the increase in appearance cycle. Table l. Measurement results of molding properties Example 2 3rIi. 10 weight z and 70 weight ll, respectively. , 20 weight χ
A multilayer sheet was obtained in the same manner as in Example 1 except for the following changes. This adhesive also had sufficient adhesive strength. Table 2 shows the adhesive composition and adhesive strength. Examples 3 and 4 Using the same three components as in Example 1, the mixing ratio was as follows:
In Example 3, 703i1! , 20 weight z, 10
A multilayer sheet was obtained in the same manner as in Example 1, except that in Example 4, the amount was changed to 60% by weight, 520% by weight, and 20% by weight. These adhesives also had sufficient adhesive strength. Table 2 shows the adhesive composition and adhesive strength. Examples 5 and 6 Using the same three precepts as in Example 1, the mixing ratio was
In Example 5, each was 45 times 1! , 47-fold tz, 8-fold I
A multilayer sheet was obtained in the same manner as in Example 1, except that in Example 6, the weight was changed to 35% by weight, 35% by weight, and 30%.
These adhesives also had sufficient adhesive strength. Table 2 shows the adhesive strength and adhesive strength. Example 7 A multilayer sheet was obtained in the same manner as in Example 6 except that in the 3rfc subsystem of Example 6, component (b) was changed to a styrene-isoprene-styrene blank copolymer. These adhesives also had sufficient adhesive strength. Glue assembly precepts,
The adhesive strength is shown in Table-2.

Example 8 A multilayer sheet was obtained in the same manner as in Example 6 except that in the three-component system of Example 6, component (b) was changed to a styrene-ethylene-butylene-styrene block copolymer. These adhesives also had sufficient adhesive strength. Table 3 shows the adhesive composition and adhesive strength. Comparative Examples 1 and 2 In Comparative Example 1, component (a) '' was used as an adhesive, respectively.
A multilayer sheet was obtained in the same manner as in Example 1, except that EEA 6170'' was used in Comparative Example 2, and 100 weight 1z of (b) Kanbun's 1 Toughprene A'' was used in Comparative Example 2. The adhesive strength of these adhesives was low. Table 3 shows the adhesive composition and adhesive strength. Comparative Example 3 In a two-component system of the component 'EEA 6170' and the component 'Toughblen A#', 50-H
A multilayer sheet was obtained in the same manner as in Example 1 except that z was 50% by weight. The adhesive strength of this adhesive was low. Table 3 shows the adhesive strength of the adhesive.

Comparative Examples 4 and 5 Using the same three precepts as in Example 1, the mixing ratio was as follows:
In Comparative Example 4, the weight was 3 and 77, respectively! , 20 layers ii! D. In Comparative Example 5, a multilayer sheet was obtained in the same manner as in Example 1 except that the weight was changed to 75 weights, 115 weights χ, and 20 weights χ. The adhesive strength of these adhesives was low. Table 4 shows the adhesive composition and adhesive strength. Comparative Example 6 Using the same three precepts as in Example 1, the mixing ratio was changed to 2.
Example 1 except that the weight was changed to 0 weight z, 30 weight z, and 50%
A multilayer sheet was obtained in the same manner as above. The adhesive strength of this adhesive was low. Table 4 shows the adhesive composition and adhesive strength.

Comparative Example 7 In the method of Example 1, (a) Precepts' EEA 617
0' was replaced with ethylene-vinyl acetate copolymer (formerly (a)
・2,5, vinyl acetate content 1 zu heavy i! ) A multilayer sheet was obtained in the same manner as in Example 1 except that the following was used. The adhesive strength of this adhesive was low. Table of adhesive composition and adhesive strength.
Shown in 4. Additionally, this multilayer sheet was burnt and had a strong odor, making it impossible to use it for food applications in particular. [Effects of the Invention] The adhesive of the present invention has excellent adhesion in laminated layers of PS resin and PP, so it can be used as a laminated layer for packaging and ceremonial purposes that has good formability, heat resistance, and oil resistance. can get things.

Table 2 Table 3 Table 4

Claims (1)

[Claims] 1. (a) Copolymers 5 to 8 consisting of unsaturated carboxylic acid and/or unsaturated carboxylic acid ester and α-olefin
0% by weight (b) 10-80% by weight of a block copolymer of styrene and conjugated diene or its hydrogenated product; and (c) 10-40% polypropylene resin. Adhesive for laminates 2 according to Claim 1, wherein the copolymer of unsaturated carboxylic acid ester and α-olefin is a copolymer of ethylene and ethyl acrylate. , the adhesive for laminates according to claim 1, wherein the copolymer of styrene and conjugated diene is a block copolymer of styrene and butadiene.