JPH09255930A - Acrylic emulsion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acrylic emulsion compsn. contg. a tackifier resin integrally mixed therein and having a mechanical stability. SOLUTION: An acrylic copolymer obtd. from at least one (meth)acrylic monomer and at least one monomer having an ethylene oxide-derived nonionic hydrophilic group and a hydrophilic-lipophilic balance of 12 to 20 is mixed with a tackfier resin. The resulting mixture is then dispersed in water.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acrylic emulsion composition, and more particularly to an acrylic emulsion composition in which tackifying resins are integrally compounded.

[0002]

2. Description of the Related Art In recent years, acrylic adhesives have been widely used in place of natural rubber and synthetic rubber adhesives because of their excellent balance of physical properties and durability. In particular, solvent-free acrylic pressure-sensitive adhesives, particularly acrylic emulsion-type pressure-sensitive adhesives, have been widely used in response to work environment problems such as organic solvent poisoning and fire, and environmental problems such as hydrocarbons.

On the other hand, acrylic adhesives are
It is well known that by adding a tackifying resin such as a terpene-based or rosin-based resin, it is possible to improve the adhesive property, particularly the adhesiveness to an adherend such as a polyolefin-based resin,
It is being implemented. In the acrylic emulsion type pressure-sensitive adhesive as well, many attempts have been made to improve the pressure-sensitive adhesive properties by adding the above tackifying resin. However, each of these attempts has a problem that some of the adhesive properties are improved but some of the adhesive properties are rather deteriorated.

For example, in JP-A-63-256672, an acrylic polymer emulsion has a softening point of 11
Disclosed is an aqueous pressure-sensitive adhesive composition consisting of several types of tackifying resin emulsions such as rosin-modified phenolic resin at 0 to 150 ° C., and having a polyolefin base material such as polypropylene and polyethylene, particularly adhesion to curved surfaces thereof, that is, anti-flagging property. The effect is described when possible. But,
The aqueous pressure-sensitive adhesive composition disclosed in JP-A-63-256672 mentioned above has mechanical stability (for example, coating stability).
Will be significantly worse.

Further, in JP-A-58-185668, there is disclosed a compound in which a tackifying resin is dissolved or dispersed in a mixture of acrylic monomers containing a monomer having a crosslinkability, or a compound thereof. A highly water-resistant copolymer emulsion containing a tackifying resin that performs polymerization while continuously adding an emulsion composition dispersed in water containing an emulsifier to a polymerization liquid containing water, an emulsifier and a polymerization catalyst. A method of making a mold adhesive is disclosed. However, the above-mentioned JP-A-58-
The method for producing a copolymer emulsion type adhesive having excellent water resistance disclosed in Japanese Patent No. 185668 has a problem that polymerization stability is deteriorated when a large amount of tackifying resin is added.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and an object thereof is to obtain an acrylic emulsion in which tackifying resins having mechanical stability are integrally mixed. Providing a composition.

[0007]

The present invention according to claim 1 discloses one or more kinds of (meth) acrylic monomers and one or more kinds of hydrophilic-lipophilic balance (Hydrophilic-Lipophilic-Bal).
ance) is in the range of 12 to 20. An acrylic copolymer obtained from a monomer having an ethylene oxide nonionic hydrophilic group is mixed with a tackifier resin, and then the mixture is dispersed in water. The main point is an acrylic emulsion composition.

According to a second aspect of the present invention, in the acrylic emulsion composition according to the first aspect, an acrylic polymer other than the acrylic copolymer used in the acrylic emulsion composition is dispersed in water. The gist of the invention is an acrylic emulsion composition obtained by mixing an acrylic emulsion.

The present invention according to claim 3 uses the acrylic emulsion composition according to claim 1 which uses an acrylic copolymer having a weight average molecular weight of 50,000 to 200,000, and a weight average molecular weight of 40. The gist is an acrylic emulsion composition obtained by mixing an acrylic polymer in the range of 10,000 to 2,000,000 with an acrylic emulsion in which water is dispersed.

The (meth) acrylic monomer is not particularly limited as long as it is a compound having a (meth) acryloyl group in the molecule, and examples thereof include methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, lauryl acrylate, acrylic acid, methacrylic acid, acrylamide, methacrylamide, N-isopropylacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 4-hydroxybutyl acrylate, etc. Is mentioned.

In addition to the above-mentioned one or more kinds of (meth) acrylic monomers, for example, maleic acid, itaconic acid, N-vinylpyrrolidone, N-vinylcaprolactam, styrene, and Copolymerizable monomers such as vinyl acetate, various macromonomers, polyfunctional (meth) acrylates and the like may be copolymerized. As for these monomers and macromonomers, monomers other than the above (meth) acrylic monomers may be used alone, or two or more kinds may be used in combination. The amount of the above-mentioned monomer or macromonomer other than the above-mentioned one or more (meth) acrylic monomers is 0 to 100 parts by weight of the above-mentioned one or more (meth) acrylic-based monomers.
100 parts by weight is preferred.

The monomer having a nonionic hydrophilic group means a hydrophilic-lipophilic balance (Hydrophilic-Lipophilic).
-Balance, hereinafter abbreviated as HLB) is a nonionic component of ethylene oxide having a range of 12 to 20, and a double bond copolymerizable with the above-mentioned (meth) acrylic monomer and other monomers or macromonomers. Other than the above characteristics, the compound having, is not particularly limited, but for example, polyoxyethylene monomethacrylate (manufactured by NOF CORPORATION, trade name: Blemmer PE-200, Blemmer PE series of Blemmer PE-350). , Methoxypolyoxyethylene monomethacrylate (manufactured by NOF CORPORATION, trade name: BLEMMER PME-200, BLEMMER PME-400, BLEMMER PME-4000 BLEMMER PME series), allylated (methoxy) polyoxyethylene (NOF Corporation, Product Name: Uniox P
KA-5001-5010 UNIOX PKA series), propenyl group-added polyoxyethylene nonyl phenyl ether (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade names: Aqualon RN-10, Aqualon RN-20, Aqualon RN-).
30, Aqualon RN-40, Aqualon RN series), polyoxyethylene nonyl phenyl ether with allyl group (manufactured by Asahi Denka Co., Ltd., trade name: ADEKA RESORP NE-
20, Adekari Soap NE-30, Adekari Soap NE
-40 Adekari soap NE series) and the like. Further, the monomer having a nonionic hydrophilic group is
They may be used alone or in combination of two or more.

The HLB of the monomer having a nonionic hydrophilic group is defined as a value obtained by dividing the weight fraction of the ethylene oxide nonionic component by 5 as shown in the following formula (1). HLB = (E / 5) (1) (where E is the weight fraction of the polyoxyethylene portion)

When the HLB of the monomer having a nonionic hydrophilic group is less than 12, the acrylic emulsion composition has poor dispersibility and a stable O / W type emulsion cannot be obtained. The amount of the nonionic hydrophilic group-containing monomer to be blended is preferably 1 to 30 parts by weight, and more preferably 3 to 20 parts by weight, based on 100 parts by weight of the one or more (meth) acrylic monomers.

In addition to the above-mentioned monomer having a nonionic hydrophilic group, if necessary, a sulfonate, a sulfate, a phosphate,
A monomer having an anionic hydrophilic group such as a carboxylate may be used. Examples of the monomer having an anionic hydrophilic group include monomers having an anionic hydrophilic group such as allyl group-added polyoxyethylene alkylphenyl ether sulfonates and propenyl group-added polyoxyethylene alkylphenyl ether sulfonates. Can be mentioned. The blending amount of the monomer having an anionic hydrophilic group is preferably 0 to 5 parts by weight, more preferably 0.3 to 3 parts by weight, based on 100 parts by weight of the one or more (meth) acrylic monomers. is there.

The method of copolymerizing the above-mentioned one or more kinds of (meth) acrylic monomers with one or more kinds of monomers having a nonionic hydrophilic group is not particularly limited.
For example, a solution polymerization method, an ultraviolet (UV) polymerization method, an emulsion polymerization method, a suspension polymerization method and the like can be mentioned. In the above copolymerization, the polymerization initiator used is not particularly limited, for example, potassium persulfate, persulfates such as ammonium persulfate, water-soluble azo compounds such as azobiscyanovaleric acid, hydrogen peroxide. And a reducing agent are used in combination. The amount of the polymerization initiator added is about 0.01 to 1 part by weight based on 100 parts by weight of the one or more (meth) acrylic monomers.

If necessary, a chain transfer agent such as dodecyl mercaptan may be used in order to adjust the molecular weight of the resulting acrylic copolymer. The amount of the chain transfer agent added is 1 or more of the (meth) acrylic monomer 1 described above.
It is about 0 to 0.5 parts by weight with respect to 00 parts by weight.

In order to adjust the viscosity of the acrylic emulsion obtained as described above, a viscosity modifier such as polyacrylic acid salt or water-soluble urethane resin may be used if necessary. The amount of the viscosity modifier added is 0 based on 100 parts by weight of the one or more (meth) acrylic monomers.
It is about 2 parts by weight.

In addition, the above acrylic emulsion is used, if necessary, in order to enhance the cohesive strength of the coating film obtained, in order to enhance the cohesive strength of the coating film, an aziridine crosslinking agent, a block or self-emulsifying isocyanate crosslinking agent, a carbodiimide crosslinking agent, or a metal emulsion. A crosslinking agent such as a crosslinking agent may be used. The amount of the cross-linking agent to be blended is about 0 to 30 parts by weight based on 100 parts by weight of the one or more (meth) acrylic monomers.

Further, the acrylic emulsion may be added with additives such as an antioxidant, a light stabilizer, a preservative and a coloring agent, if necessary.

In the acrylic emulsion composition of the present invention according to claim 2, the acrylic polymer other than the acrylic copolymer according to claim 1 is not particularly limited as long as it is the acrylic polymer as described above. Although not limited to, for example, 100 parts by weight of (meth) acrylate such as methyl acrylate, methyl methacrylate, ethyl methacrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, and lauryl acrylate. On the other hand, a monomer having a carboxyl group such as acrylic acid, methacrylic acid, maleic acid or itaconic acid, or a hydroxyl group such as 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate or 4-hydroxybutyl acrylate is used. 20 parts by weight or less, more preferably 10 parts by weight or less of a monomer having a functional group such as a nitrogen-containing monomer such as N-vinylpyrrolidone, N-vinylcaprolactaacrylamide, methacrylamide, and N-isopropylacrylamide. Acrylic copolymers are preferably used.

In the acrylic emulsion composition according to the third aspect of the present invention, the weight average molecular weight of the acrylic copolymer according to the first aspect is limited to the range of 50,000 to 200,000. When the weight average molecular weight of the acrylic copolymer is less than 50,000, the coating film obtained from the acrylic emulsion composition has low cohesive force, heat resistance, etc. and sufficient mechanical strength cannot be obtained. When the weight average molecular weight is more than 200,000, when the acrylic copolymer is prepared by dispersing the acrylic copolymer in water to prepare an acrylic emulsion composition, the amount of the solvent used becomes large. Large energy loss.

In the acrylic emulsion composition of the present invention according to claim 3, an acrylic copolymer having a weight average molecular weight in the range of 50,000 to 200,000 is used and mixed with the acrylic emulsion composition according to claim 1. The weight average molecular weight of the acrylic polymer is limited to the range of 400,000 to 2,000,000.

When the weight average molecular weight of the acrylic polymer is less than 400,000, the cohesive force of the coating film obtained from the acrylic emulsion composition is low and the mechanical strength such as tensile strength cannot be sufficiently obtained. Further, the weight average molecular weight is 2
If it exceeds, 000,000, the adhesive strength of the acrylic emulsion composition will be low.

The above-mentioned acrylic polymer having a weight average molecular weight of 400,000 to 2,000,000 has a weight average molecular weight of 400,000 to 200.
In addition, the acrylic copolymer according to claim 1 may be used, or an ordinary acrylic polymer or acrylic copolymer generally available on the market may be used.

An emulsifier may be used in preparing the acrylic emulsion. The emulsifier is not particularly limited, but examples thereof include anionic emulsifiers such as dodecylbenzene sulfonates, alkyl sulfates, polyoxyethylene alkylphenyl ether sulfonates, polyoxyethylene alkylphenyl ethers, and polyoxyethylene. Examples include nonionic emulsifiers such as alkyl ethers. Further, polyoxyethylene monomethacrylate, methoxypolyoxyethylene monomethacrylate, allylated (methoxy) polyoxyethylene, propenyl group-added polyoxyethylene nonylphenyl ether, allyl used in the acrylic emulsion composition of the present invention according to claim 1. Anionic hydrophilic groups such as monomers having a nonionic hydrophilic group of group-added polyoxyethylene nonylphenyl ether, polyoxyethylene alkylphenyl ether sulfonates with allyl group, and polyoxyethylene alkylphenyl ether sulfonates with propenyl group A monomer having a is also suitably used as the emulsifier.

The tackifying resin is not particularly limited, but for example, gum rosin, tall oil rosin, wood rosin, polymerized rosin, hydrogenated rosin, disproportionated rosin,
Rosin ester, polymerized rosin ester, hydrogenated rosin ester, disproportionated rosin ester, rosin-based tackifying resin such as rosin-modified phenol resin, terpene resin, hydrogenated terpene resin, phenol resin, terpene phenol resin,
Examples of the tackifying resin include hydrogenated terpene phenol resin, xylene resin, aliphatic petroleum resin, alicyclic petroleum resin, aromatic petroleum resin, coumarone resin, and styrene resin. Further, these tackifying resins may be used alone or in combination of two or more kinds. The softening point of the tackifying resin is preferably 0 ° C or higher, more preferably 100 ° C or higher. The blending amount of the tackifying resin is 10 or more kinds of the (meth) acrylic monomer 10 described above.
It is preferably 5 to 100 parts by weight, more preferably 10 to 70 parts by weight, based on 0 parts by weight.

Since the acrylic emulsion composition of the present invention according to claim 1 is constituted as described above, in general, an acrylic emulsion composition containing a tackifying resin having reduced mechanical stability is Perhaps the acrylic copolymer wraps the tackifying resin molecule, it has excellent film-forming ability and strong adhesiveness even at low concentration, good dispersion stability, and excellent mechanical stability. Show. Therefore, it can be stably used even in applications where a high shearing force is applied, and exhibits excellent chemical stability.

The acrylic emulsion composition of the present invention according to claim 2 is constituted as described above, and therefore, in general, an acrylic emulsion composition containing a tackifying resin having reduced mechanical stability is The acrylic emulsion composition according to claim 1, which shows extremely excellent mechanical stability, probably because the acrylic copolymer used in the acrylic emulsion composition according to claim 1 encloses the tackifying resin molecule. Combined with the film-forming ability of acrylic polymers other than the acrylic copolymer used for, it has excellent film-forming ability and strong adhesiveness even at low concentration, good dispersion stability, and excellent It is presumed that it exhibits excellent mechanical stability and, therefore, can be used stably even in applications where a high shear force is applied, and exhibits excellent chemical stability. .

The acrylic emulsion composition of the present invention according to claim 3 is constituted as described above, and therefore, in general, an acrylic emulsion composition containing a tackifying resin having a reduced mechanical stability, Weight average molecular weight 5
The acrylic emulsion composition according to claim 1, which contains an acrylic copolymer in the range of 10,000 to 200,000, may wrap the tackifying resin molecule, may exhibit extremely excellent mechanical stability, and may have a weight average molecular weight. In combination with the film-forming ability of the acrylic emulsion using the acrylic polymer in the range of 400,000 to 2,000,000, it has excellent film-forming ability and strong adhesiveness even at a low concentration, and has stable dispersion stability. It is presumed that it exhibits excellent mechanical stability, and therefore can be stably used even in applications where high shearing force is applied, and exhibits excellent chemical stability.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

(Example 1) n-butyl acrylate 43
Parts by weight, 43 parts by weight of 2-ethylhexyl acrylate,
Acrylic acid 4 parts by weight, Bremmer PE-350 (trade name, manufactured by NOF Corporation, 10 parts by weight of polycondensation product of 8 ethylene glycol monoacrylate ester terminals), 0.2 parts by weight of benzoyl peroxide, and 0.03 parts by weight of dodecyl mercaptan in 8% ethyl acetate
The reaction was carried out for a time to obtain an acrylic polymer solution having a solid content of 40% by weight.

A tackifying resin (manufactured by Arakawa Chemical Co., Ltd., trade name: Super Ester A-1) was added to the acrylic polymer solution.
00, a disproportionated rosin ester) in an ethyl acetate solution in a solid content weight ratio of (acrylic polymer) :( tackifying resin) = 100: 30 and mixed sufficiently to obtain the above acrylic polymer and tackifying resin. To prepare an ethyl acetate solution, which was then dispersed in ion-exchanged water according to a conventional method and the solvent was removed to prepare an acrylic emulsion having a solid content of 50% by weight.

(Example 2) In the polymerizable composition of Example 1, except for benzoyl peroxide, a photo-curing agent (manufactured by Nippon Ciba Geigy, trade name: Irgacure 651) was used.
1 part by weight was blended, and the solution polymerization in Example 1 using ethyl acetate as a solvent was replaced with ultraviolet polymerization using a high-pressure mercury lamp, and the polymerization reaction product was dissolved in ethyl acetate to obtain a solid content of 40 parts by weight. % Acrylic polymer solution was obtained to prepare an acrylic emulsion having a solid content of 50% by weight in the same manner as in Example 1.

(Example 3) In the polymerizable composition of Example 1, except for benzoyl peroxide, the compounding amount of dodecyl mercaptan was changed from 0.03 part by weight to 0.05 part by weight to prepare ion-exchanged water. Dispersion, 0.1 part by weight of ammonium persulfate was polymerized by emulsion polymerization according to a conventional method, and the polymerization reaction product was dried and then dissolved in ethyl acetate to obtain an acrylic polymer solution having a solid content of 40% by weight. An acrylic emulsion having a solid content of 50% by weight was produced in the same manner as in Example 1 except that the above was obtained.

(Comparative Example 1) n-butyl acrylate 48
Parts by weight, 48 parts by weight of 2-ethylhexyl acrylate,
Acrylic acid 4 parts by weight, propenyl group-added polyoxyethylene nonylphenyl ether ammonium sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-10) 0.6
Parts by weight and 0.05 parts by weight of dodecyl mercaptan are dispersed in ion-exchanged water, followed by a conventional method using 0.1 parts by weight of ammonium persulfate, polymerized by emulsion polymerization, and an acrylic emulsion obtained by the polymerization reaction, Tackifying resin (Arakawa Chemical Co., Ltd., trade name: Super Ester E-
720, emulsion of disproportionated rosin ester) was mixed at a solid content weight ratio of (acrylic polymer) :( tackifying resin) = 100: 30 to prepare an acrylic emulsion having a solid content of 50% by weight.

Comparative Example 2 Of the polymerizable composition of Comparative Example 1, the polymerizable composition excluding dodecyl mercaptan and the tackifying resin of Example 1 were mixed at a weight ratio of 100: 30, and the mixed composition was prepared. Was dispersed in ion-exchanged water, and 0.1 part by weight of ammonium persulfate was used to polymerize by emulsion polymerization according to a conventional method to prepare an acrylic emulsion having a solid content of 50% by weight.

Example 4 Preparation of Acrylic Emulsion-1: 48 parts by weight of n-butyl acrylate, 48 of 2-ethylhexyl acrylate
Parts by weight, acrylic acid 4 parts by weight, propenyl group-added polyoxyethylene nonylphenyl ether ammonium sulfate (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., trade name: Aqualon HS-1
0) 0.6 parts by weight and 0.05 parts by weight of dodecyl mercaptan were dispersed in ion-exchanged water to prepare acrylic emulsion-1 having a solid content of 50% by weight.

Preparation of acrylic emulsion-2: To the acrylic polymer solution of the polymerization reaction product of Example 1, was added an ethyl acetate solution of tackifying resin (super ester A-100) at a solid content weight ratio of (acrylic polymer). ): (Tackifying resin) = 1: 1, except that the acrylic emulsion having a solid content of 50% by weight was prepared in the same manner as in Example 1.
2 was produced.

The above acrylic emulsion-1 and acrylic emulsion-2 were mixed in a solid content weight ratio of (acrylic polymer) :( tackifying resin) = 100: 30 to obtain an acrylic emulsion (solid content of 50 weight). %)
Was produced.

(Example 5) In preparation of the acrylic emulsion-2 of Example 4, the acrylic polymer solution of the polymerization reaction product of Example 1 was replaced by the acrylic polymer solution of the polymerization reaction product of Example 2. An acrylic emulsion (solid content: 50% by weight) was prepared in the same manner as in Example 4 except that

Example 6 In the preparation of the acrylic emulsion-2 of Example 4, the acrylic polymer solution of the polymerization reaction product of Example 1 was replaced with the acrylic polymer solution of the polymerization reaction product of Example 3. An acrylic emulsion (solid content: 50% by weight) was prepared in the same manner as in Example 4 except that

(Comparative Example 3) The acrylic emulsion-1 of Example 4 and the tackifying resin (Super Ester E-720) of Comparative Example 1 were used in a solid content weight ratio of (acrylic polymer) :( tackifying resin) = The mixture was mixed at 100: 30 to prepare an acrylic emulsion (solid content 50% by weight).

The "solid content of emulsion" used in the above Examples and Comparative Examples was measured by the following method. (Measurement method of solid content) 1.5 g of the emulsion was placed in an aluminum cup and dried at 110 ° C. for 3 hours, and the residual amount (weight: g) was divided by the weight of the collected emulsion (1.5 g) to obtain a percentage. The solid content was used.

In order to evaluate the mechanical stability of the acrylic emulsions obtained in the above Examples and Comparative Examples, they were tested by the method shown below. The test results are shown in Table 1.

1. Mechanical stability (%): Marlon type mechanical stability tester (Kyowa Interface Science Co., Ltd., trade name: emulsion / latex mechanical stability measurement-recorder CMS-A
Type), 50 g of emulsion as a sample is sampled in a test container and 1000 rp under a pressure of 10 kg / cm ^2.
After rotating for 5 minutes at m, the aggregate in the test container was
Filter through a 0 mesh wire mesh and dry at 110 ° C. for 3 hours,
As in the following formula, the mechanical stability (%) was defined as the percentage of the value obtained by dividing the dry residual amount (weight: g) by the weight of the sampled emulsion (50 g).

[0047]

[Equation 1]

[0048]

[Table 1]

[0049]

Since the acrylic emulsion composition of the present invention is constructed as described above, it has excellent film-forming ability and strong adhesiveness even at a low concentration, has good dispersion stability, and is excellent. It exhibits mechanical stability. Therefore, it can be stably used even in applications where a high shearing force is applied, and exhibits excellent chemical stability.

Claims (3)

[Claims] 1. A hydrophilic-lipophilic balance comprising at least one (meth) acrylic monomer and at least one hydrophilic-lipophilic balance.
Acrylic copolymer obtained from a monomer having an ethylene oxide nonionic hydrophilic group having a hydrophilic-balance of 12 to 20 is mixed with a tackifying resin, and then the mixture is dispersed in water. An acrylic emulsion composition comprising: 2. The acrylic emulsion composition according to claim 1 is mixed with an acrylic emulsion in which an acrylic polymer other than the acrylic copolymer used in the acrylic emulsion composition is dispersed in water. Acrylic emulsion composition. 3. The acrylic emulsion composition according to claim 1, which uses an acrylic copolymer having a weight average molecular weight of 50,000 to 200,000, and a weight average molecular weight of 400,000 to 20.
An acrylic emulsion composition prepared by mixing an acrylic polymer in the range of 0,000 with an acrylic emulsion in which water is dispersed.