JPS6139998B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention is a copolyester based adhesive that has extremely excellent performance as an adhesive for soft polyvinyl chloride resin (polyvinyl chloride resin adhesives, polyvinyl chloride resin adhesives, and other adherends). Regarding adhesives. Conventionally, polybutylene terephthalate or copolyesters mainly having a polybutylene terephthalate skeleton have excellent mechanical strength, thermal stability, dimensional stability, weather resistance, chemical resistance, etc., and are widely used as various molding materials and other materials. It is used. Taking advantage of these excellent properties, various attempts have been made to apply polyester to other fields, and hot melt adhesives are one such application. However, polybutylene terephthalate itself or a copolyester containing polybutylene terephthalate as a main component has a high melting point and high crystallinity, so it is extremely difficult to use it as a hot melt adhesive. On the other hand, when adhering soft polyvinyl chloride (vinyl chloride polymers and copolymers) containing plasticizers to themselves or to other adherends, the plasticizers contained (esters such as dioctyl phthalate) are usually used as adhesives. ) Polyurethane-based adhesives (solution type, emulsion type, film type) are currently used, but there are problems with price, ease of handling, and hygiene. In terms of sexuality, problems remain. Taking the above circumstances into consideration, the present inventors have developed a material that has excellent mechanical strength, thermal stability, dimensional stability, weather resistance, chemical resistance, etc., has a low liquefaction temperature, and has adhesive strength to soft polyvinyl chloride. As a result of intensive study to obtain a polyester resin with strong properties, the present invention was completed. That is, the present invention uses 30 to 70 mol% of terephthalic acid residues, 10 to 40 mol% of isophthalic acid residues, and 10 to 40 mol% of aliphatic dicarboxylic acid residues having 6 to 12 carbon atoms as the acid components of the copolymerized polyester. mol% and other acid residues are 0-10 mol%, and as a polyol component 80
mol% or more of 1,4-butanediol, other diols 20 mol% or less, 0 to 10 mol% of the diol consists of trivalent or higher polyol, and the reduced viscosity (ηsp/c) is 0.3 to 0.9 This is an adhesive for soft polyvinyl chloride resin that contains a copolymerized polyester with a dl/g as an active ingredient. In the present invention, terephthalic acid residue is 30 mol% as an acid component among the constituent components of the copolymerized polyester.
If it is less than 70 mol%, polyester will lack cohesive strength and mechanical strength, and if it exceeds 70 mol%, it will have too high crystallinity, lack flexibility, and have a high melting temperature, making it difficult to use as an adhesive. . If the content of isophthalic acid residues is less than 10 mol%, it is difficult to balance the cohesive force of the molecules and the melting temperature, and if it exceeds 40 mol%, there is a drawback that heat resistance and durability are lacking. In addition, there are 10 aliphatic dicarboxylic acid residues having 6 to 12 carbon atoms.
If it is less than mol %, flexibility will be lacking, and if it exceeds 40 mol %, there will be a drawback that cohesive force and chemical resistance will be reduced. In addition to the above-mentioned acid residues, if desired, aliphatic dicarboxylic acid residues having 13 or more carbon atoms such as brassic acid and dimer acid, and alicyclic dibasic acid residues such as hexahydroterephthalic acid and hexahydrophthalic acid may also be used. It is possible to have an oxyacid residue such as P-oxybenzoic acid or 1,2-hydroxystearic acid, or a trivalent or higher acid residue such as trimellitic acid or pyromellitic acid as a constituent component. The amount may range up to 10 mol %; if it exceeds 10 mol %, the adhesive intended for the present invention cannot be obtained. On the other hand, 1.4-butanediol accounts for 80 mol% or more of the polyol components of the copolymerized polyester components;
If it is less than mol%, the adhesive strength and durability to soft polyvinyl chloride tend to decrease. As other polyol components, diols such as ethylene glycol, propylene glycol, various aliphatic diols such as 1,6-hexanediol, and aromatic glycols such as bisphenol A are added in a range of 20 mol% or less. Within the range that does not interfere with the present purpose, that is, in an amount up to 10 mol% of the diol,
Trimethyl or higher polyols such as trimethylolpropane, glycerin, and pentaerythritol may also be added. Among the copolymerized polyesters using such raw materials, those particularly useful in the present invention have a reduced viscosity (ηsp/
c) is 0.3 to 0.9 dl/g, preferably 0.4 to 0.8. Here, the reduced viscosity (ηsp/c) is in m-cresol solvent, polymer concentration (C) 0.25g/0.25dl, 40℃
This is the value measured at If the ring base viscosity of the copolymerized polyester in the present invention is less than 0.3 dl/g, the cohesive force of the molecules is weak, so strong adhesive force cannot be obtained, and if it exceeds 0.9 dl/g,
Adhesive strength is weak due to insufficient wetting of the adherend during heat bonding. The copolymerized polyester of the present invention is produced by a general method used in the production of other linear polyesters. That is, for example, terephthalic acid or its ester-forming derivatives, isophthalic acid or its ester-forming derivatives, aliphatic dicarboxylic acids or its ester-forming derivatives are directly esterified or transesterified after adding the glycols and a melting medium. Another method is to add the glycols to polybutylene terephthalate, heat depolymerize, and then add isophthalic acid or an ester-forming derivative thereof and an aliphatic dicarboxylic acid or an ester-forming derivative thereof together with a catalyst for polymerization. There is a way. Examples of such catalysts include oxides, halides, acetates, etc. of metals such as zinc, manganese, and magnesium, as well as para-toluenesulfonic acid, titanate esters, etc., and the amount used is 0.01 to 100% of the total system. 0.5% by weight is preferred. By specifying the acid component and glycol component as described above, the copolymerized polyester of the present invention has a softening point lower than that of conventional polyesters, generally below 200°C, particularly 50 to 170°C, and is suitable for use as a hot melt adhesive. The properties are suitable for handling. In the present invention, in addition to the above-mentioned copolymerized polyester, flow control agents such as benzoin, dimethyl terephthalate, Modaflow (manufactured by Monsanto) and Acronal 4F (manufactured by Basf), plasticizers such as dioctyl phthalate and P-oxybenzoic acid are used. phosphorus compounds such as triphenyl phosphate, stabilizers such as hindered phenols, fillers such as calcium carbonate, zinc oxide, titanium oxide, talc, glass fiber, Aerosil, polyethylene, polypropylene, nylon, epoxy resin, By blending resins other than polyester, such as petroleum resins, it is possible to improve flow characteristics during heating and melting, adhesive characteristics, and other physical properties. In this way, it is possible to obtain a hot melt adhesive that is suitable for adhering so-called soft polyvinyl chloride (vinyl chloride polymer and copolymer) containing a plasticizer to itself or to other adherends. The present invention will be specifically explained below using Examples. Example 1 Dimethyl terephthalate, 1,4-butanediol, ethylene glycol, and a known catalyst were added in catalytic amounts to a reaction vessel, and transesterification was carried out at 140 to 190°C in a nitrogen stream. After completion of the transesterification reaction, add isophthalic acid, adipic acid or dodecanedioic acid in the amount shown in Table 1, and carry out the esterification reaction at 190 to 210°C.
Simultaneously increase temperature and reduce pressure, 50mmHg, 210-270
Polymerization was carried out at .degree. C., and when the polymerized product reached a predetermined reduced viscosity, the reaction was terminated, and polyester resins A to M as shown in Table 1 were obtained. Note that copolymerized polyesters E to M are comparative examples. The obtained copolymerized polyester is cut into a thickness of approximately
After forming into a 100μ film, the film was sandwiched between soft polyvinyl chloride sheets (size 10cm x 2.5cm, thickness 0.5mm) and heat sealed at 170℃ and 5Kg/cm ² for 2 minutes. Place the pieces in a Tensilon at 23℃.
Then, the adhesive strength was measured when the T was peeled off at 80° C. and at a speed of 200 mm/min. The results are shown in Table-2. Also, the T after keeping the test piece in an 80℃ oven for one week
The peel strength is shown in Table 2. Example 2 The peel strength was measured at 23°C after adhering soft polyvinyl chloride sheets and various adherends as shown in Table 3 using the same method as in Example 1 using copolymerized polyester B. The results are shown below. -3. Example 3 Copolymerized polyester B was heated to bath temperature using a hot melt applicator (Model XI manufactured by Nordson).
At 200°C and nozzle outlet temperature of 220°C, melt-extrude various adherends (a) shown in Table 4 (fabric weight: approx. 200 g/m ² ) and quickly attach various adherends (b) while keeping pressure applied. After cooling, the adhesion was completed. Table 4 shows the T-peel strength of each test piece at 23°C.

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Claims (1)

[Claims] 1 As the acid component of the copolymerized polyester, terephthalic acid residues are 30 to 70 mol%, and isophthalic acid residues are 10% by mole.
~40 mol%, 10 to 40 mol% of aliphatic dicarboxylic residues having 6 to 12 carbon atoms, and 0 to 10 mol% of other acid residues, while 1.4- as a polyol component.
80 mol% or more of butanediol, other diols
20 mol% or less, and 0 to 10 mol% of the diol is 3
It consists of a polyol with a polyol having a polyol or higher viscosity, and has a reduced viscosity (η
An adhesive for soft polyvinyl chloride resin, which contains a copolymerized polyester having an sp/c) of 0.3 to 0.9 dl/g as an active ingredient.