JPH03221509A - Aqueous dispersion - Google Patents

Abstract

PURPOSE:To obtain a novel aqueous dispersion capable of providing excellent tacky property to an aqueous dispersion type tacky agent or adhesive by adding the tacky agent or adhesive by dispersing a specific isopropenyltoluene based copolymer into an aqueous medium. CONSTITUTION:The aimed aqueous dispersion obtained by dispersing an isopropenyltoluene based copolymer obtained polymerizing isopropenyltoluene with 4-5C unsaturated hydrocarbon in an aqueous medium, preferably at a ratio of 20-70wt.%. Furthermore, the copolymer is preferably obtained by polymerizing 100 pts.wt. isopropenyltoluene consisting of 20-60% para-isomer, 40-80% meta-isomer and 0-10% ortho-isomer with 5-100 pts.wt. 4-5C unsaturated hydrocarbon such as 1-butene in the presence of a Friedel-Crafts catalyst such as TiCl4. When the above-mentioned copolymer is dispersed, an anionic surfactant having 9-15 HLB is preferably used as an emulsifying agent.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a novel aqueous dispersion, and more particularly to isopropenyl toluene, which is a copolymer of isopropenyl toluene and an unsaturated hydrocarbon having 4 to 5 carbon atoms. The present invention relates to an aqueous dispersion of a toluene-based copolymer, and an aqueous dispersion comprising the aqueous dispersion and an acrylic emulsion.

[Conventional technology]

A typical field in which tackifiers are used is the field of adhesives.

Conventionally, organic solvent solution type adhesives have been widely used in this field, but since such adhesives use organic solvents, there are problems in terms of safety and health and pollution during the manufacturing process, and it is necessary to eliminate them. Solvent recovery equipment was required to prevent this.

On the other hand, an aqueous dispersion (acrylic emulsion) of an acrylic resin has also been proposed as a non-organic solvent type, that is, an aqueous dispersion type adhesive. Since water-based dispersion type adhesives do not use organic solvents, health and safety and pollution problems in the manufacturing process are resolved, and there is no need for equipment to recover organic solvents, reducing the WMv of manufacturing equipment. It has the advantage of being able to perform 8-digitization.

However, the adhesive strength of water-based dispersion type adhesives is not sufficient.

In order to improve the adhesive strength of aqueous dispersion type adhesives, rosin-based tackifiers that rely on natural raw materials are used. On the other hand, attempts have also been made to use petroleum resins obtained from petroleum fractions, which have excellent compatibility with acrylic resins, as tackifiers.

However, it is extremely difficult to emulsify petroleum resins, and no aqueous dispersion that can be used in practice has been obtained.

[Problem to be solved by the invention]

It is an object of the present invention to provide an aqueous dispersion that imparts excellent tack when added to an aqueous dispersion pressure sensitive adhesive or adhesive.

Another object of the present invention is to provide an aqueous dispersion comprising the above aqueous dispersion and an acrylic emulsion, which has excellent adhesiveness and adhesive strength.

[Means to solve the problem]

The present invention is the following aqueous dispersion.

(]) An aqueous dispersion characterized in that an isopropenyltoluene-based copolymer consisting of a copolymer of isopropenyltoluene and an unsaturated hydrocarbon having 4 to 5 carbon atoms is dispersed in an aqueous medium.

(2) The aqueous dispersion described in (]) above, which is dispersed with a nonionic surfactant.

(3) It is characterized by consisting of an aqueous dispersion in which an isopropenyltoluene-based copolymer consisting of a copolymer of isopropenyltoluene and an unsaturated hydrocarbon having 4 to 5 carbon atoms is dispersed in an aqueous medium, and an acrylic emulsion. Aqueous dispersion.

In the present invention, the aqueous dispersions of (1) and (2) above are used as Aqueous Dispersion I, and the aqueous dispersion of above (3) is used as Dispersion II.
It is called.

The isopropenyltoluene constituting the isopropenyltoluene copolymer used in the present invention includes ortho, meta, and para isomers, and mixtures thereof. It is preferred to use a mixture of 40 to 80% by weight of isomers and ○ to 10% by weight of orthoisomers. Further, isopropenyltoluene having a purity of 80% by weight or more and containing a small amount of other polymerizable monomers such as styrene, vinyltoluene, α-methylstyrene, etc. can also be used. In place of isopropenyltoluene, compounds similar to isopropenyltoluene, such as styrene, vinyltoluene, α-
Even if methylstyrene or the like is used, a copolymer with good performance cannot be obtained.

The unsaturated hydrocarbon having 4 to 5 carbon atoms constituting the isopropenyltoluene copolymer used in the present invention includes:
Any fraction selected from the fractions containing unsaturated hydrocarbons having 4 to 5 carbon atoms produced as by-products during petroleum refining and cracking can be used.

Fractions containing unsaturated hydrocarbons with 4 to 5 carbon atoms (hereinafter referred to as C4 and C7 fractions), which are by-produced during petroleum refining and cracking, usually have a boiling point range of -15 to +45°C under normal pressure.
1-butene, imbutylene, 2-butene, 1,3-butadiene, 1-pentene, 2-methyl-
1-butene, 3-methyl-1-butene, 2-pentene,
Contains polymerizable monomers such as isoprene, 3-pentadiene, and cyclopentadiene. In the present invention,
Any fraction containing a polymerizable monomer selected from the C4 and C6 fractions, that is, not only the C4 and C6 fractions, but also the C4 fraction,
A C4 fraction excluding butadiene, a C5 fraction, a C9 fraction excluding isoprene, a C5 fraction excluding cyclopentadiene, etc. can be used.

The isopropenyltoluene copolymer used in the present invention can be obtained by copolymerizing 5 to 100 parts by weight of the above unsaturated hydrocarbon having 4 to 5 carbon atoms to 100 parts by weight of the isopropenyltoluene. It will be done. By copolymerizing both in such a ratio, a copolymer having excellent performance as a tackifier can be obtained.

The copolymerization reaction of the image constituent components is preferably carried out in the presence of a Friedel-Krach catalyst.

As the Friedel-Krach catalyst, known Friedel-Kraf catalysts can be used, specifically aluminum chloride, aluminum bromide, dichloromonoethylaluminum, titanium tetrachloride, tin tetrachloride, boron trifluoride, trifluoride, etc. Examples include various complexes of boron oxide.

The amount of Friedel-Krauch catalyst used is the total amount of raw materials 1
The amount is usually 0.1 to 5 parts by weight, preferably 0.5 to 3 parts by weight per 00 parts by weight.

In order to remove the reaction heat and suppress the viscosity of the reaction solution, the copolymerization reaction of the image constituent components is preferably carried out using a solvent so that the concentration of the polymerizable monomer is about 10 to 50% by weight.

Suitable solvents include, for example, aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; alicyclic hydrocarbons such as dichloropentane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbons such as toluene, xylene, ethylbenzene, and mesitylene. : and mixtures thereof.

The polymerization temperature varies depending on the composition of the raw materials, but is generally preferably in the range of -50 to +50°C. The reaction time is usually 10
A range of minutes to 10 hours is preferred.

After the polymerization is completed, the catalyst is decomposed with an aqueous alkaline solution or methanol, and then washed with water and unreacted raw materials, solvent, etc. are removed by stripping to obtain the desired isopropenyltoluene copolymer. The softening point (ring and ball method) of the copolymer thus obtained is usually 30 to 140.
It is ℃.

Aqueous dispersion (2) of the present invention is one in which an isopropenyltoluene copolymer is dispersed in an aqueous medium. Examples of the aqueous medium include water or a medium containing water as a main component.

The proportion of the isopropenyltoluene copolymer contained in the aqueous dispersion (1) of the present invention is desirably 10 to 80% by weight, preferably 20 to 70% by weight. Furthermore, an aqueous dispersion I having a suitable viscosity and easy handling can be obtained.

An emulsifier is usually used to disperse the isopropenyltoluene copolymer in an aqueous medium. As an emulsifier,
Nonionic or anionic surfactants are used. Among these, nonionic surfactants are preferred, and those with an HLB of 9 to 15 are particularly preferred.

The amount of emulsifier added is 1 part isopropenyltoluene copolymer.
00 parts by weight to 30 parts by weight, preferably 5 parts by weight
Preferably, the amount is between 20 and 20 parts by weight. By adjusting the amount of the emulsifier added in such a proportion, an aqueous dispersion 1 having excellent adhesive strength and a good emulsified state can be obtained.

Aqueous dispersion 1 of the present invention is produced by dispersing an isopropenyltoluene-based copolymer in an aqueous medium with stirring.

The dispersion method is not particularly limited and various known methods can be adopted, but usually the isopropenyltoluene copolymer, the emulsifier, and the aqueous medium are mixed and stirred while raising the temperature.
It is preferable to adopt a method in which the isopropenyltoluene copolymer is dissolved and dispersed and then the temperature is lowered.

The temperature during dissolution and stirring varies depending on the composition of the isopropenyltoluene copolymer, but is usually 100 to 200°C,
The temperature is preferably 120 to 180°C.

Further, the stirring time is usually preferably 15 minutes to 3 hours.

The particle size of the emulsion thus produced is usually 0.1 to 1.5 cm.

Specific methods of dispersion include the following (a) direct emulsification method;
Examples include (b) solvent substitution method and (c) phase inversion method.

(a) Direct emulsification method A method in which the isopropenyltoluene copolymer, emulsifier, and aqueous medium are added all at once and stirred. When strong stirring is required, a stirrer such as a homomixer may be used. It is possible to adopt a method in which each component is continuously added to a reactor and continuously withdrawn, or it is also possible to adopt a batch method using a pressure-resistant autoclave.

(b) Solvent substitution method A method in which the isopropenyltoluene copolymer is dissolved in a suitable organic solvent in advance, an aqueous medium is added thereto successively or in its entirety, and after stirring, the organic solvent is removed. The emulsifier is usually added together with the aqueous medium, but may be added in advance.

(C) Phase inversion method A method in which the isopropenyltoluene copolymer and the emulsifier are kneaded, then an aqueous medium is successively added to effect phase inversion, and then a large amount of an aqueous medium is added to emulsify. An extruder is used when strong mixing is required.

Among these, direct emulsification using a pressure autoclave is preferred.

Additives such as a thickener and an antifoaming agent may be added to the aqueous dispersion I thus obtained, if necessary.

The aqueous dispersion I of the present invention can be used as a tackifier for aqueous dispersion pressure-sensitive adhesives and adhesives. Addition of the aqueous dispersion (1) of the present invention improves the tackiness of the pressure-sensitive adhesive or adhesive, but heat-sealing further improves the peel strength. Furthermore, by mixing the aqueous dispersion (1) of the present invention with an acrylic emulsion, the aqueous dispersion (2) which exhibits excellent adhesion to various plastics can be obtained.

Examples of the above-mentioned acrylic emulsions include emulsions of single polymers of acrylic esters, and emulsions of copolymers of acrylic esters, methacrylic esters, vinyl acetate, styrene, acrylonitrile, acrylic acid, and the like. Such acrylic emulsions are commercially available, and commercially available products can be used.

The mixing ratio of the aqueous dispersion I and the acrylic emulsion is:
The weight ratio of (isopropenyltoluene copolymer in aqueous dispersion I)/(shelf fat in acrylic emulsion) is 5/
95-80/20, preferably 40/60-60/40
It is desirable to mix so that

The aqueous dispersion (1) of the present invention can be used as a pressure-sensitive adhesive, an adhesive, a printing binder, a fiber processing binder, etc. In particular, an aqueous dispersion (concentration of the acrylic emulsion is 2
0 to 85% by weight) is used as an adhesive, and an aqueous dispersion ■ (concentration of acrylic emulsion is 20 to 85% by weight), which is an acrylic emulsion mainly composed of methyl acrylate or ethyl acrylate and an aqueous dispersion ■ added to it, is used for printing. It can be suitably used as a binder and a fiber processing binder.

〔Effect of the invention〕

According to the present invention, since a specific isopropenyltoluene-based copolymer is dispersed in an aqueous medium, an aqueous dispersion that imparts excellent tackiness when added to an aqueous dispersion type adhesive or adhesive is produced. can get.

Furthermore, since the aqueous dispersion and the acrylic emulsion are mixed, an aqueous dispersion with excellent adhesiveness and adhesive strength can be obtained.

〔Example〕

Next, examples of the present invention will be described.

Example 1 100 g of isopropenyltoluene (purity 99.2%) obtained by distillation separation from the acid splitting product of cymene hydroperoxide in the cymene method cresol production process
, 10 g of C9 and C6 fractions containing unsaturated hydrocarbons obtained from thermal decomposition of petroleum naphtha and 150 g of toluene were charged into an autoclave, and 1.5 g of BF3 phenol complex as a catalyst was added while stirring and keeping the temperature at 0°C. about 10
It was dripped in minutes. Stirring was then continued for an additional 3 hours.

Next, 5% by weight aqueous sodium hydroxide solution 50+++Q was added and stirred vigorously for 30 minutes to decompose the catalyst, then the aqueous layer was separated, and the polymerized oil was washed with water until it became neutral, and unreacted oil and solvent toluene were removed. was distilled off, leaving 105g as a residue.
A pale yellow blocky copolymer was obtained. The composition of the raw material monomers and the properties of the produced copolymer were as follows.

Isopropenyltoluene composition 0: Isopropenyltoluene m-isopropenyltoluene P-isopropenyltoluene C4, C5 fraction composition C Butadiene n-Pentane Isoprene 1.3-Pentadiene Cyclopentadiene Others (Fraction with boiling point below 80'C) Copolymer properties Weight % 5.3 60.4 33.5 0.8 Weight % 1.5 0 .4 1.3 10.5 19.8 8.7 4.4 20.9 5.1 5.6 2.8 3.1 15.9 Hue 1 (Gardner, ASTM D 154-58),
Softening point: 95°C (ring and ball method), number average molecular weight: 730, bromine number: 15 (ASTMD 1158-57).

540 g of the above copolymer, 400 g of water, and surfactant (Emulgen 420, Kao Corporation!li!!, trade name)
60g was charged into a pressure autoclave and mixed and stirred.

] After the temperature was raised to 50°C, stirring was carried out for 2 hours, and after completion of the stirring, the mixture was cooled with water and returned to room temperature. The resulting emulsion had a p)I of 5.5, a solid content of S degree of 59.8% by weight, and a particle size of 1.0.

Tsukazol TS- in the above emulsion and acrylic emulsion
805, manufactured by Nippon Carbide Industries Co., Ltd., product name) and 5
They were mixed and stirred at a ratio (weight ratio) of 0.0150. This mixture was applied to a PET film (film thickness 25-) at 10g/bottom, dried at 120°C for 3 minutes, and then coated on a stainless steel plate at 2k
1 at a speed of 300 mm/win using a rubber roller
It was moved back and forth to be crimped and used as a sample. This was subjected to a 180° peel test using a tensile testing machine at a tensile speed of 300 mm/mjn. The results are shown in Table 1.

Example 2 Using the same copolymer as in Example 1, a 5:1 mixture (weight ratio) of Emulgen 420 and Emulgen 408 (both Kao Corporation !12, trade names) as surfactants during emulsification. ) An emulsion was obtained in the same manner as in Example 1 except that the following was used.

Next, a peel test was conducted using the above emulsion in the same manner as in Example 1. The results are shown in Table 1.

Example 3 In Example 1, the amount of BF3 phenol complex added was 2
．． The copolymer was prepared in the same manner as in Example 1 except that the amount was 1 g. The properties of the obtained copolymer were as follows: hue 1. Softening point 7
The temperature was 0°C, the number average molecular weight was 540, and brominated 1O.

This copolymer was emulsified in the same manner as in Example 1.

The obtained emulsion had a pH of 5.1, a solid content concentration of 59.6% by weight, and a particle size of 0.56.

A peel test was conducted using the above emulsion in the same manner as in Example 1. The results are shown in Table 1.

Comparative Example 1 A peel test was conducted in the same manner as in Example 1 using the acrylic emulsion used in Example 1 as the sole adhesive.

The results are shown in Table 1. Table 1

Claims (3)

[Claims] (1) An aqueous dispersion characterized in that an isopropenyltoluene-based copolymer consisting of a copolymer of isopropenyltoluene and an unsaturated hydrocarbon having 4 to 5 carbon atoms is dispersed in an aqueous medium. (2) Claim (1) in which the dispersion is performed using a nonionic surfactant.
Aqueous dispersions as described. (3) It is characterized by consisting of an aqueous dispersion in which an isopropenyltoluene-based copolymer consisting of a copolymer of isopropenyltoluene and an unsaturated hydrocarbon having 4 to 5 carbon atoms is dispersed in an aqueous medium, and an acrylic emulsion. Aqueous dispersion.