JPH03281339A - Chlorine-containing resin laminate - Google Patents

Abstract

PURPOSE:To enhance interlaminar bonding strength by forming a laminate of a vinyl chloride resin and/or a vinylidene chloride resin layer and an ethylene/vinyl acetate copolymer resin layer having a specific melt flow rate. CONSTITUTION:A layer of a vinyl chloride resin and/or vinylidene chloride resin (A) and a layer of a modified ethylene/vinyl acetate copolymer resin (B) with a melt flow rate of 0.5 - 12g/10 min and total vinyl acetate content of 20 - 80 wt.% obtained by reacting an ethylene/vinyl acetate copolymer with vinyl acetate content of 5 - 50 wt.% with a vinyl acetate monomer under a graft reaction condition are laminated by coextrusion molding to obtain a chlorine-containing resin laminate. The obtained laminate is especially useful in the field of the coating of the inner surface of a metal pipe difficult in lamination heretofore.

Description

Detailed Description of the Invention [Materials of the Invention] [Industrial Field of Application] The present invention provides a chlorine-gold-platinum resin laminate, particularly a layer of vinyl chloride resin and/or vinylidene chloride resin and a specific modified ethylene laminate. -Relates to a chlorine-containing resin laminate comprising a layer of vinyl acetate copolymer resin.

<Prior art> Vinyl chloride resin has many excellent properties for boat fishing, such as solvent resistance, water resistance, acid resistance, alkali resistance, and flame retardancy, and is used in films, electric wire coatings, flooring materials, Widely used for pipes, plates, etc. Furthermore, vinylidene chloride resin generally has excellent moisture-proofing properties and gas-barrier properties, and is widely used as various packaging films and moisture-proofing materials for coatings.

However, both resins are relatively easily degraded by heat and light and are too hard, so it is necessary to add appropriate stabilizers and plasticizers to them. In particular, soft vinyl chloride resin contains about 30 to 40% of plasticizer, and therefore has the disadvantage of poor cold resistance, oil resistance, and creep resistance. In order to compensate for the drawbacks, it is thought that lamination with polyolefins such as polyethylene, polypropylene, or other base materials may be effective.

On the other hand, various adhesive resins have been proposed for bonding vinyl chloride resin and/or vinylidene chloride resin to other base materials. For example, an ethylene/vinyl acetate copolymer resin having a relatively high vinyl acetate content can be mentioned.

<Problem to be solved by the invention> However, since the adhesiveness between such vinyl chloride resin and/or vinylidene chloride resin and the ethylene/vinyl acetate copolymer resin is still not necessarily good,
In hopes of improving this adhesion, an attempt was made to introduce a larger amount of vinyl acetate in the form of alpha copolymerization with ethylene. The problem was that the adhesive strength could not be improved much after all.

[Summary of the invention]

Summary of the Invention The present invention aims to improve these drawbacks, and based on the knowledge that using a specific modified copolymer significantly improves adhesion and achieves this objective. This led to the completion of the invention.

That is, the chlorine-containing resin laminate of the present invention comprises a layer (A layer) of vinyl chloride resin and/or vinylidene chloride resin, and an ethylene/vinyl acetate copolymer and vinyl acetate having a vinyl acetate content of 5 to 50% by weight ff1%. The melt flow rate obtained by subjecting the monomer to graft reaction conditions is 0. 5~
12g/10 minutes, and the total vinyl acetate content is 20~8
0 weight? It is characterized in that it is composed of a layer (B layer) of a modified ethylene/vinyl acetate copolymer resin of o.

Effect> The chlorine-containing resin laminate of the present invention has a vinyl acetate content of 5 to 5
A melt flow rate of 0.5 to 30 g/10 minutes obtained by subjecting 50 uffi% of ethylene/vinyl acetate copolymer and vinyl acetate monomer to grafting reaction conditions, and a total vinyl acetate content of 20 to 80% by weight. By using the modified ethylene/vinyl acetate copolymer resin, it has strong interlayer adhesion and can combine the advantages of vinyl chloride resin and/or vinylidene chloride resin with the properties of other base materials, so it is suitable not only for industrial products but also for industrial products. , we have great expectations for its application in the field of daily necessities.

[Detailed description of the invention]

[1'3 Structure of chlorine-containing resin laminate The chlorine-gold-platinum resin laminate of the present invention basically consists of a layer made of a chlorine-containing resin (layer A) and a modified ethylene/vinyl acetate copolymer resin layer ( B layer) are laminated.

(1) Chlorine-containing resin layer (layer A) Examples of the vinyl chloride resin and/or vinylidene chloride resin constituting one layer (layer A) of the chlorine@white resin laminate of the present invention include polyvinyl chloride, bottle Vinylidene chloride, vinyl chloride/vinylidene chloride copolymer, vinyl chloride/
Vinyl acetate copolymer, vinyl chloride/ethylene copolymer,
Commercially available products such as vinyl chloride/propylene copolymer, vinyl chloride/acrylonitrile copolymer, vinyl chloride/styrene copolymer, etc. can be used as appropriate, but among these, polyvinyl chloride, vinyl chloride/vinylidene chloride, etc. Preference is given to using polymers. Furthermore, it is also possible to blend other polymers with the vinyl chloride resin and/or vinylidene chloride resin as long as the effect of the present invention is not maintained within a length of 1 m. Furthermore, polyvinyl chloride and acrylonitrile-butadiene copolymer rubber are compatible with each other and can be mixed in larger amounts, which is preferable. Of course, the plasticizers and stabilizers that are usually added to these resins,
It is also possible to blend various additives such as inorganic fillers, antistatic agents, and pigments.

(2) Modified ethylene/vinyl acetate copolymer resin layer (layer B) The modified ethylene/vinyl acetate copolymer constituting the other layer (layer B above) of the chlorine-containing resin laminate of the present invention is made of vinyl acetate. Ethylene-vinyl acetate copolymer (hereinafter referred to as "EVAJ") having a content of 5 to 50% by weight, preferably 10 to 35% by weight.
A modified polymer obtained by subjecting a vinyl acetate monomer and a vinyl acetate monomer to graft reaction conditions, which has a melt flow rate (MFR) of 0. 5 to 12 g/10 minutes, preferably 1 to 10 g/10 minutes, and the total vinyl acetate content is 20
~80% by weight, preferably 20-50% by weight resinous.

(U) Production of modified ethylene/vinyl acetate copolymer resin layer The most important modified ethylene/vinyl acetate copolymer resin layer in the chlorine-containing resin laminate of the present invention was produced by the following method. It is preferable that

(1) Raw materials (a) Ethylene/vinyl acetate copolymer (EVA) To produce a modified ethylene/vinyl acetate copolymer, ethylene/vinyl acetate with an unmodified vinyl acetate content of 5 to 50% by weight is used. Polymer (EVA) is used.

If the vinyl acetate content of the EVA used here is less than the above amount, the amount of vinyl acetate to be impregnated and polymerized will be limited, resulting in insufficient properties of the resulting modified ethylene/vinyl acetate copolymer. If the above amount is exceeded, the softening point of EVA is low, so that particles may melt and adhere to each other or form agglomerates during polymerization, which is not preferable. The MFR of the second EVA is generally 5~
400g/10 minutes, especially 10-200g/l 0 minutes is suitable.

Further, the amount of vinyl acetate monomer used is determined based on the amount of total vinyl acetate to be contained in the modified EVA finally produced. If the content of total vinyl acetate contained in the modified EVA is less than the above-mentioned amount, it is difficult to achieve the desired purpose in terms of the balance between adhesiveness and strength. Moreover, when the total vinyl acetate content exceeds the above amount, moldability deteriorates.

This modified resin may be mixed with other polymers, inorganic fillers, stabilizers, colorants, etc., as long as they do not impede the effects of the present invention. For example, petroleum resins and tackifiers commonly used in hot melt adhesives can also be blended.

Such modified EVA has an MFR within the above range, and if this V FR is less than the above range, it will be difficult to form a thin film, while if it exceeds the above range, handling during molding will be difficult. This is undesirable because it becomes difficult to obtain a uniform laminate.

(b) Vinyl acetate monomer The vinyl acetate monomer used in producing the modified ethylene/vinyl acetate copolymer resin of layer B constituting the chlorine-containing resin laminate of the present invention may be a commercially available vinyl acetate monomer. I can do it. A mixture of a majority of the weight of this vinyl acetate monomer with another vinyl monomer copolymerizable with it may also be used. Examples of other vinyl polymers include vinyl esters such as vinyl propionate and vinyl versatate; acrylic acid, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid,
Unsaturated white organic acids or derivatives thereof such as methyl methacrylate, butyl methacrylate, maleic anhydride, dimethyl maleate, and di(2-ethylhexyl) maleate, unsaturated aromatic monomers such as styrene, 25-dichlorostyrene, etc. Body: Unsaturated mononitriles such as acrylonitrile and methacrylonitrile; vinyl chloride, vinyl chloride, vinyliso7, etc., and tuvalide.

The vinyl triphosphate monomer is usually added in an amount of 10 to 50 parts by weight, preferably 15 to 30 parts by weight, per 100 parts by weight of the ethylene/vinyl acetate copolymer. It can be added all at once or in parts. EVA like above
When subjecting vinyl acetate monomers to graft reaction conditions, radicals are usually generated except for reactions caused by radiation.
Use J.

(c) Radical generator As the radical generator used in producing the modified ethylene/vinyl acetate copolymer resin of layer B, general-purpose radical generators can be used, but preferable grafts described later can be used. In relation to the reaction method, it is preferable that the decomposition temperature is 50°C or higher and that it is oil-soluble. Here, "decomposition temperature" is the temperature at which the decomposition rate of the radical generator becomes 50% when 0.1 mole of the radical generator is added to 1 liter of benzene and left at a certain temperature for 10 hours. , the so-called "decomposition temperature to obtain a half-life of 10 hours".

If this decomposition temperature is low, the polymerization of the vinyl acetate monomer may proceed abnormally, and a homogeneous modified polymer cannot be obtained.

However, on the contrary, it is also possible to carry out the decomposition stepwise or continuously by suitably combining those with high decomposition temperatures and those with low decomposition temperatures, thereby achieving an efficient graft reaction.

Examples of such radical generators include 2゜4-dichlorobenzoyl peroxide, t-butyl peroxybivalate, 0-methylbenzoyl peroxide, bis-3,5,51-limethylhexanoyl peroxide, and octanoyl peroxide. Peroxide, benzoyl peroxide, t-butyl peroxy-2-ethylhexanoate, cyclohexanone peroxide, 2,5-dimethyl-2,5-dibenzoyl peroxyhexane, t-butyl peroxybenzoate, di-t- Butyl-shiba-oxyphthalate, methyl ethyl ketone peroxide,
Organic peroxides such as dicumyl peroxide and di-t-butyl peroxide.

Examples include azo compounds such as azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile).

The amount of the radical generator to be used is within the range of about 0.01 to 10% by weight based on the amount of vinyl acetate monomer used, and is adjusted as appropriate depending on the type of radical generator and reaction conditions. If the amount used is less than this, the reaction will not proceed smoothly;
If the amount exceeds this amount, a gel will easily form in the modified EVA, making it difficult to achieve the effects of the present invention.

(2) Production of modified ethylene/vinyl acetate copolymer Is it possible to produce a modified ethylene/vinyl acetate copolymer by subjecting each of these raw materials to a graft polymerization reaction? This is a particularly preferable method because it is easy to manufacture the gel and to control the gel content.

That is, an aqueous suspension containing ethylene/vinyl acetate copolymer particles with a vinyl acetate content of 5 to 50 and a particle weight of 9°, a vinyl acetate monomer, and a radical generator is heated to a temperature at which the decomposition of the initiator does not substantially occur. The monomer is added to the EVA particles until the amount of free monomer that is not impregnated is 20 parts by weight.
A preferred method is to impregnate the suspension so that it is less than f19(i) and then further raise the temperature of the aqueous suspension to complete the polymerization of the 7-mer. This method will be described below.

(a) Impregnation Step A typical preferred method for impregnating EVA particles with vinyl acetate monomer in an aqueous medium involves adding a radical generator (and optionally other additives) to an aqueous suspension of EVA particles. Additive) or dissolved vinyl acetate monomer is added and stirred, or EVA particles are added to an aqueous dispersion of vinyl acetate monomer in which a radical generator is dissolved and stirred.

In the impregnation step, industrially, the temperature should be raised to a temperature at which the radical generating agent is not substantially decomposed, so that impregnation can be carried out efficiently.
It is preferable to operate at ℃.

Since EVA is relatively compatible with vinyl acetate monomer, even if less than 20% by weight, preferably less than 10% by weight, of vinyl acetate monomer is liberated before the start of the graft polymerization reaction, this will be removed during the polymerization. Since it is impregnated with the EVA particles, only the free vinyl acetate monomer is polymerized and vinyl acetate homopolymer particles are not precipitated independently from the modified WEVA particles. The impregnation time is usually about 2 to 8 hours.

The amount of EVA particles and vinyl acetate monomer used in the aqueous suspension is 5 to 10 parts by weight per 100 parts by weight of water.
It is usually about 0 parts by weight.

Such aqueous suspensions can be stably maintained in a suspended/dispersed state simply by thorough stirring; however, using an appropriate suspension stabilizer can more easily and stably maintain a suspended/dispersed state. can be adjusted. Suspension stabilizers in this case include, for example, water-soluble polymeric substances such as polyvinyl alcohol, methylcellulose, and hydroxycellulose; anionic surfactants such as alkylbenzene sulfonates;
Nonionic surfactants such as polyoxyethylene alkyl ether; or water-insoluble inorganic salts such as magnesium oxide and calcium phosphate are used alone or in combination in an amount of about 0.01 to 10% by weight based on water. Ru.

When impregnating EVA particles with vinyl acetate monomer (and radical generator, etc.), auxiliary materials such as plasticizers, lubricants, and antioxidants can be impregnated at the same time (these auxiliary materials have already been added to the EVA). Yes 1: There is also a J match,
It can also be blended after the graft polymerization reaction).

(b) Graft polymerization process If the temperature of the aqueous suspension thus prepared is raised to a temperature above which the radical generator used decomposes at an appropriate rate, the impregnated vinyl acetate monomer will undergo graft polymerization. to produce modified EVA particles.

The aqueous suspension during graft polymerization is preferably stirred appropriately.

The polymerization temperature should generally be selected appropriately within the range of 50 to 100°C, or need not be constant throughout the kraft polymerization process. When the polymerization temperature exceeds 100° C., not only is it easy to cause kelization, but also the particles are likely to split into fine particles and become sticky and agglomerated together due to stirring.

The graft polymerization time is usually about 2 to 10 hours. After the graft polymerization, if a treatment similar to the post-treatment of ordinary aqueous suspension polymerization of vinyl monomers (for example, styrene) is performed, modified EVA particles can be obtained in which the shape of the EVA particles used is maintained almost unchanged.

Therefore, the EVA used before modification may be in powder form, but
Considering the handling during the subsequent molding process, it is convenient to use a particulate form.

That is, it is preferable that the particle size is of a size normally used as a molding material because the produced modified EVA can be used as a molding material as it is, and the average particle size is generally 1 to 8, preferably 3. It is about 7 dragons. No significant change in its dimensions was observed before and after the modification treatment.

(III) Production of chlorine-containing resin laminate (1) Lamination The chlorine-containing resin and the modified ethylene/vinyl acetate copolymer are formed into a film or sheet and laminated to produce the chlorine-containing resin laminate of the present invention. As for the manufacturing method, a known method of laminating the resins of both layers by coextrusion molding, press molding, extrusion lamination molding, etc. is used.

(2) Multilayering As the chlorine-containing resin laminate of the present invention, we have mainly described a laminate consisting of only the above two types of layers, but the chlorine-containing resin laminate of the present invention has these two layers as its basic constituent layers. 3
It also includes a resin laminate having a multilayer structure consisting of more than 22 layers. In the case of a laminate with such a multilayer structure,
Examples of materials that can be used as base materials for other layers include acrylonitrile-butadiene-styrene (ABS) resin, styrene resins such as polystyrene, α-olefin resins such as polyethylene and polypropylene, acrylonitrile-butadiene rubber, styrene-butadiene rubber, etc. various rubbers; fluorine resins such as polyvinyl fluoride and polyvinylidene fluoride; metals such as aluminum and iron; thermosetting resins such as unsaturated polyesters, epoxy resins, and urethane resins, thermal i'J plastic polyesters, polycarbonates, and nylon. Engineering plastics such as

Modified EV constituting one layer of the chlorine-containing resin laminate of the present invention
A resin can be laminated with these base materials without using an adhesive. Of course, you can also attach it with adhesive.

At this time, in laminating with other base materials, the modified EVA resin used in the present invention contains an unsaturated carboxylic acid or a derivative thereof, an unsaturated glycidyl compound in the form of graft modification or copolymerization, or From the viewpoint of adhesive properties, it is preferable to use a saponified product obtained by hydrolyzing a portion of vinyl acetate in modified EVA.

Here, "containing in the form of graft modification or copolymerization" refers to a method in which these unsaturated compounds are simultaneously grafted together with the vinyl acetate monomer when the vinyl acetate monomer is subjected to a graft reaction, and as EVA before modification. A method of using modified EVA which contains these unsaturated compounds in the form of graft or copolymerization in advance, a method of further graft copolymerizing these unsaturated compounds to modified EVA, a method of graft-modifying modified EVA with these unsaturated compounds Alternatively, there is a method of kneading a modified α-olefin polymer contained in the form of a copolymer.

Here, unsaturated carboxylic acids or derivatives thereof include carboxylic acid groups, acid anhydride groups, ester groups, carboxylic acid metal salts,
Examples of unsaturated compounds having a carboxylic acid amide group include acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, and derivatives thereof, with maleic anhydride being particularly preferred.

Examples of unsaturated grindyl compounds include glycidyl methacrylate, glycidyl acrylate, and the like.

The chlorine-containing resin laminate of the present invention comprises vinyl chloride resin and/or
In addition, it is particularly useful in the field of coating the inner surface of pipes such as metal pipes, which has conventionally been difficult to laminate in the molding of vinylidene chloride resin.

[Experiment example]

Example 1 Manufacturing process of modified EVA particles 20 kg of water in a 50 liter autoclave.

0.6 kg of tricalcium phosphate as a suspending agent and 0.6 g of sodium dodecylbenzenesulfonate are mixed to prepare an aqueous medium, and EVA particles with a particle size of 3 to 4 mm (MF
R30g/10 minutes, vinyl acetate content 33% by weight) 7kg
Add and stir to suspend.

Separately, 64.5 g of t-butyl peroxyvivalate and 3.6 g of benzoyl peroxide were dissolved in 3 kg of vinyl acetate, and this was added to the above suspension system, and nitrogen was introduced into the autoclave to bring the system to 0.5 g. It was pressurized to 5 kg/c. Furthermore, the temperature inside the autoclave was raised to 50° C., and the mixture was left at this temperature for 3 hours without stirring to impregnate the entire amount of vinyl acetate containing a polymerization initiator into the EVA particles. Next, this suspension was heated to 63°C, left to stand at this temperature for 8 hours with stirring, and further heated to 70°C for 2 hours, 8 hours.
The temperature was raised to 0°C and maintained for 1 hour to complete polymerization.

After cooling, the solid contents were taken out and washed with water to obtain 10 kg of modified EVA particles.

The MFR of the obtained modified 'REV particles is 1. 0g/10 min, the total vinyl acetate content was 53% by weight.

Manufacturing process of chlorine-containing resin laminate The modified EVA particles obtained by the above steps and polyvinyl chloride (Vinicafun Pound D-1 manufactured by Mitsubishi Monsando)
26) were molded into sheets each having a thickness of 0.5 mm at a temperature of 140° C. using a compression molding method.

The evaluated sheets were further laminated by compression molding at a temperature of 140° C. to produce a laminated sheet of modified EVA and polyvinyl chloride.

This laminate was cut into a short Il shape with a width of 15 m + m, and after peeling off the part, the modified 1EVA part and the polyvinyl chloride part at both ends were sandwiched between the chuck of an Instron type testing machine, and the tensile speed was 50 mm/ The interlayer adhesion strength of the laminate was measured at 980 g/15 m+*.

Comparative Example 1 Instead of the modified EVA particles obtained by the manufacturing process of modified EVA particles of Example 1, vinyl acetate content was 45% by weight.
EVA (Levablen 450 manufactured by Bayer: MFR2
A laminate was produced and evaluated in the same manner as in Example 1, except that the laminate was used (g/l, 0 min).

The adhesive strength was 300g/15mm.

Example 2 The modified EVA particles obtained by the manufacturing process of modified EVA particles of Example 1 were molded using a 35-diameter T-die molding machine manufactured by Braco, at a molding temperature of 200°C, a resin temperature of 200°C, and a screening speed. 30-55 rpm, take-up speed 10m/
Various films having a thickness of 25 to 50 μm were molded under the molding conditions of 10 seconds.

Next, a 50 μm thick film produced using the above T-die molding machine and an impact-resistant polystyrene (Denka Styrol HI-E4 manufactured by Denki Kagaku Co., Ltd.) sheet (thickness 0.5 mm) were stacked together, and a 2 kg sheet was layered using a heat sealer. Thermal bonding was carried out at a temperature of 120°C for 2 seconds under a pressure of /c-.

Next, this adhesive body was cut out to a width of 15 mm, and Example 1
Adhesive strength was measured in the same manner as above.

The adhesive strength was 1400+r/15mm.

Comparative Example 2 Instead of the modified EVA particles obtained by the modified EVA manufacturing process of Example 1, EV with a vinyl acetate content of 45% by weight was used.
When T-die molding was carried out in the same manner as in Example 2 except that A (Levabren 450 manufactured by Bayer) was used, a thin film (thickness of 50 μm or less) could not be obtained due to slow cooling.

Example 3 The 50 μm thick film of modified EVA used in Example 2 was used as an intermediate layer, and this was combined with a 0.5 μm thick polyvinyl chloride sheet and a 0.5 μm thick polystyrene sheet.
Thermal bonding was carried out at a temperature of 60° C. in the same manner as in Example 2, and the interlayer adhesive strength between the modified EVA layer and the polystyrene layer was measured and found to be 800 g/15°.

Claims (1)

[Claims] 1. Grafting reaction conditions between a vinyl chloride resin and/or vinylidene chloride resin layer (layer A) and an ethylene/vinyl acetate copolymer and vinyl acetate monomer having a vinyl acetate content of 5 to 50% by weight A layer (B layer) of a modified ethylene/vinyl acetate copolymer resin having a melt flow rate of 0.5 to 12 g/10 minutes and a total vinyl acetate content of 20 to 80% by weight, obtained by subjecting to A chlorine-containing resin laminate comprising: 2. The modified ethylene/vinyl acetate copolymer is converted into an aqueous suspension containing ethylene/vinyl acetate copolymer particles with a vinyl acetate content of 5 to 50% by weight, a vinyl acetate monomer, and a radical generator. The vinyl acetate monomer is impregnated into the ethylene/vinyl acetate copolymer particles until the amount of free monomer that is not impregnated is less than 20% by weight by increasing the temperature to a temperature at which decomposition of the agent does not substantially occur. Claim 1, wherein the aqueous suspension is further heated to complete the graft reaction.
The chlorine-containing resin laminate described in .