JPH05320607A - Production of resin for pressure-sensitive adhesive - Google Patents

Abstract

PURPOSE:To provide a resin for adhesive having improved low-temp. tackiness and initial tackiness by copolymerizing a specific acrylic ester with a polymerizable unsatd. monomer having a hydroxyl or carboxyl group in the molecule in the presence of a polyester resin. CONSTITUTION:100 pts.wt. monomer mixture comprising 65-99.99 acrylic ester of the formula (wherein R<1> is H or methyl; (n) is 0-5; and R<2> is 4-12C alkyl when (n) is 0 and 1-5C alkyl when (n) is 1-5), 0.1-10.0wt.% polymerizable unsatd. monomer having a hydroxyl or carboxyl group in the molecule, and, if necessary, another copolymerizable unsatd. monomer is polymerized in the presence of 10-40 pts.wt. polyester resin having a glass transition point of 0 deg.C or lower, a wt. average mol.wt. of 10,000-1,000,000, and a ratio of the wt.-average to the number-average mol.wt. of 3 or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a resin which gives a pressure-sensitive adhesive having excellent adhesion to a polyolefin-based adherend and good low-temperature adhesion and initial tack.

[0002]

2. Description of the Related Art As a resin for a pressure sensitive adhesive, an acrylic resin has been generally used. However, since the pressure-sensitive adhesive consisting only of acrylic resin has poor adhesion to polyolefin-based adherends, in practical use, in order to compensate for its drawbacks, rosin, rosin ester, rosin-modified resin, terpene resin, terpene It contains a tackifier such as phenol resin, phenol resin, xylene resin, coumarone resin, coumarone / indene resin, petroleum resin.

However, when a tackifier having a high softening point is blended, the adhesion to the polyolefin-based adherend is improved, but the initial tack is lowered, and the adhesive properties are particularly impaired at low temperatures.

Attempts have also been made to improve the adhesive properties at low temperatures by incorporating tackifiers, polymer plasticizers, etc., which are liquid at room temperature and have a low softening point. The adhesive strength improving effect on the body is hardly exhibited, and the adhesive strength is extremely reduced.

The action of the tackifier on the acrylic resin depends on the softening point of the tackifier, and the tackifying effect seen when the tackifier having a high softening point is compounded is an increase in resistance at the time of peeling. In this case, not only the initial tack is lowered because the glass transition temperature of the pressure-sensitive adhesive as a whole is increased, but also the adhesiveness to the polyolefin-based adherend at low temperature is reduced.

On the other hand, the effect of improving the tackiness observed when the tackifier having a low softening point is blended is based on the improvement of the wettability to the surface of the polyolefin-based adherend due to the improvement of the flow characteristics of the pressure-sensitive adhesive resin. However, in this case, since the glass transition temperature of the pressure-sensitive adhesive as a whole is low, the holding power is low.

As described above, in the conventional method for improving the tackiness using the tackifier, the tackiness to the polyolefin-based adherend, the low temperature tackiness, the initial tack and the like cannot be satisfied at the same time.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the problems of the prior art as described above, and its purpose is to have high adhesion to a polyolefin-based adherend, Another object of the present invention is to provide a resin for pressure-sensitive adhesive, which has good low-temperature adhesion and good initial tack.

[0009]

The method for producing a resin for pressure-sensitive adhesive according to the present invention, which has been able to solve the above-mentioned problems, comprises:

[0010]

[Chemical 2] (However, R ¹ is hydrogen or a methyl group, n is 0 or 1-
5 represents an integer of 5 and R ² has 4 to 1 carbon atoms when n is 0.
2 alkyl groups, and when n is an integer of 1 to 5, each represents an alkyl group having 1 to 5 carbon atoms), or two or more kinds of acrylic acid ester-based monomers: 65 to 99.99
%, And one or more polymerizable unsaturated monomers having a hydroxyl group in the molecule: 0.01 to 5.0% by weight and / or one polymerizable unsaturated monomer having a carboxyl group in the molecule Or two or more: a polymerizable unsaturated monomer mixture containing 0.1 to 10.0% by weight as a main polymerizable component, having a glass transition temperature of 0 ° C. or lower and a weight average molecular weight of 10,000 to 1,
And the ratio of weight average molecular weight / number average molecular weight is 3
It has the gist in that it is polymerized in the above polyester resin.

[0011]

The present inventors pay attention to the problems of the prior art as described above, and increase the adhesive force to a polyolefin-based adherend without impairing the adhesive property of the acrylic pressure-sensitive adhesive at low temperature. Various studies have been advanced for the purpose.

As a result, it was considered that the above-mentioned various effects can be expected in a polyester resin whose glass transition temperature (Tg) is low and whose molecular weight is large enough not to hinder the holding power.

However, according to a confirmation experiment, since such a polyester resin has a poor compatibility with an acrylic resin, the expected effect of enhancing the adhesive force to a polyolefin adherend can be obtained. I couldn't.

However, as will be described in detail later, if the monomer components that can be used as the acrylic pressure-sensitive adhesive resin are polymerized in the presence of a polyester resin having a specific molecular weight range and molecular weight distribution, they will be compatible with each other. However, it has become clear that it becomes a resin for pressure-sensitive adhesive which is excellent in both the adhesive strength to a polyolefin-based adherend and the low-temperature adhesive property.

The polyester resin coexisting in the polymerization system of the monomer for producing an acrylic resin and the monomer component used for producing an acrylic resin in the present invention will be described in detail below.

First, the polyester resin used in the present invention is produced by a known method using polyhydric alcohol and polycarboxylic acid as raw materials. To achieve the object of the present invention, the glass transition temperature ( Tg) is 0 ° C. or lower, and the weight average molecular weight is 10,000 to 1,000,000 and the “weight average molecular weight to number average molecular weight ratio” (Mw / Mn ratio) which is an index of the molecular weight distribution is 3 or more. There is a need.

If the Tg exceeds 0 ° C., the low-temperature adhesive property of the pressure-sensitive adhesive becomes poor. However, if the Tg is too low, the holding power is lowered and it cannot be put to practical use.
It is desirable to use one having a temperature of 0 ° C. or higher.

If the weight average molecular weight of the polyester resin is too small, the holding power of the pressure-sensitive adhesive obtained will be insufficient, while if it is a high-molecular weight polyester resin exceeding 1,000,000, the tackiness of the pressure-sensitive adhesive obtained will be insufficient. Properties, especially low temperature adhesion and initial tack, are reduced. The more preferable weight average molecular weight of the polyester resin is in the range of 10,000 to 100,000.

Next, the Mw / Mn ratio of the polyester resin is set to 3 or more, because the acrylic resin obtained by polymerizing in the polyester resin by making the polyester resin having a wide molecular weight distribution. This is to improve the compatibility with and if the Mw / Mn ratio is too small,
The compatibility with the acrylic resin deteriorates, resulting in poor adhesion to a polyolefin-based adherend and low-temperature adhesion properties.

The above polyester resin can be produced by a known method using polyhydric alcohol and polyhydric carboxylic acid as raw materials. Examples of the polyhydric alcohol used here include ethylene glycol, diethylene glycol,
Triethylene glycol, tetraethylene glycol,
Propylene glycol, dipropylene glycol, 1,
4-butanediol, 1,3-butylene glycol, 3
-Methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, trimethylolpropane, trimethylolethane, pentaerythritol and the like are exemplified.

As the polycarboxylic acid, maleic anhydride, fumaric acid, itaconic acid, trimellitic acid, adipic acid, sebacic acid, phthalic anhydride, isophthalic acid, terephthalic acid and the like are used. However, in the case of a polyester resin containing a large amount of an aliphatic unsaturated dibasic acid such as maleic anhydride, fumaric acid or itaconic acid as the polycarboxylic acid, the polymerizable unsaturated monomer mixture is polymerized in the polyester resin. At times, graft reaction and three-dimensionalization reaction easily occur, the flow characteristics of the obtained resin deteriorate, and the coating workability deteriorates.In particular, adhesive products that require an adhesive surface with excellent transparency and smoothness are required. When attempting to obtain it, problems such as insufficient transparency and smoothness may occur, so the amount of aliphatic unsaturated dibasic acid used should be approximately 5% of the polycarboxylic acid component. It is desired that the amount be less than 0.5%, more preferably less than 0.5%. It is also possible to use polymerized rosin or the like as one of the polybasic acids. Next, as the acrylic acid ester-based monomer represented by the general formula (1) used in the present invention, for example, acrylic acid butyl ester, acrylic acid isobutyl ester, acrylic acid secondary butyl ester, and acrylic acid secondary monomer. Tertiary butyl ester, acrylic acid amyl ester, acrylic acid isoamyl ester, acrylic acid hexyl ester, acrylic acid cyclohexyl ester, acrylic acid heptyl ester, acrylic acid octyl ester, acrylic acid isooctyl ester, acrylic acid 2-ethylhexyl ester, acrylic acid Nonyl esters, acrylic acid isononyl esters, acrylic acid decyl esters, acrylic acid dodecyl esters, acrylic acid butoxy esters, acrylic acid ethyl carbitol esters, acrylic acid methyl triglycol ester Ether, may be mentioned acrylic acid dipropylene glycol methyl ether ester, it may be used alone or can be used in combination of two or more.

The acrylic acid ester-based monomer is an essential component for imparting initial tack and tack to the pressure-sensitive adhesive, and its preferable blending amount is a ratio in the total amount of the polymerizable monomer. The range is 65 to 99.99% by weight.

If the amount is too small, the pressure-sensitive adhesive obtained cannot have sufficient initial tack and tackiness. On the other hand, if the amount is too large, the polymerizable unsaturated monomer having a hydroxyl group in the molecule and the molecule to be described later are used. Since the absolute amount of the polymerizable unsaturated monomer having a carboxyl group therein is insufficient, the resulting copolymer is insufficiently cross-linked, and the pressure-sensitive adhesive cannot be satisfactorily retained.

Next, as the polymerizable unsaturated monomer having a hydroxyl group in the molecule, for example, 2-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, hydroxybutyl (meth) acrylate,
Caprolactone-modified hydroxy (meth) acrylate [eg Daicel Chemical Company, trade name "Placcel F
M ″], a mono (meth) acrylate of polyester diol obtained from phthalic acid and propylene glycol,
(Meth) acrylic acid ester having a hydroxyl group such as mono (meth) acrylate of polyester diol obtained from succinic acid and propylene glycol, polyethylene glycol mono (meth) acrylate, polypropylene glycol mono (meth) acrylate, and the like. Can be used alone or in combination of two or more.

Specific examples of the polymerizable unsaturated monomer having a carboxyl group in the molecule include unsaturated monobasic acids such as acrylic acid, methacrylic acid and crotonic acid: maleic acid, fumaric acid, itaconic acid, Examples thereof include unsaturated dibasic acids such as citraconic acid and their monoesters. These may be used alone or in combination of two or more.

Any of these polymerizable unsaturated monomers and these acts as a crosslinkable component to enhance the holding power of the pressure-sensitive adhesive, and these monomers and may be used in combination, or The purpose can also be achieved by using only one.

The preferred amount of the polymerizable unsaturated monomer used is 0.01 to 5.
0% by weight, more preferably 0.1 to 3.0% by weight, and the preferable amount of the polymerizable unsaturated monomer used is 0.01 to 10.0% by weight, more preferably 0.5 to 10% by weight in the total amount of the polymerizable unsaturated monomer. If it is in the range of 5.0% by weight and the amount used is insufficient, a pressure-sensitive adhesive with satisfactory holding power cannot be obtained. Is reduced.

The essential polymerizable unsaturated monomer component in the present invention is as described above, but as another component, if necessary, the polymerizable unsaturated monomer, or a polymerizable unsaturated monomer other than It is also possible to use one type or two or more types together. Specific examples of such other polymerizable unsaturated monomers include aliphatic unsaturated hydrocarbons such as ethylene and butadiene; halogen-substituted aliphatic unsaturated hydrocarbons such as vinyl chloride; styrene, α -Aromatic unsaturated hydrocarbons such as methylstyrene and divinylbenzene; vinyl esters such as vinyl acetate; vinyl ethers; esters of allyl alcohol with various organic acids; unsaturated cyan compounds such as acrylonitrile; (meth) acrylamide Unsaturated amide compounds such as; unsaturated glycidyl compounds such as glucidyl (meth) acrylate; alkyl groups having 1 to 1 carbon atoms
8 methacrylic acid alkyl ester; acrylic acid alkyl ester having an alkyl group other than 4 to 12 carbon atoms and (meth) acrylic acid aryl ester; various esters of unsaturated dibasic carboxylic acid such as crotonic acid; maleic acid, Examples thereof include various diesters of unsaturated dibasic carboxylic acids such as fumaric acid.

In the present invention, the polymerizable unsaturated monomer mixture containing the above-mentioned polymerizable unsaturated monomer and / or optionally further in the presence of one or more of the above polyester resins. At this time, the polyester resin is used in an amount of 10 to 40 parts by weight based on 100 parts by weight of the polymerizable unsaturated monomer mixture. However, when the amount of polyester resin is insufficient, the adhesive force to the olefin-based adherend cannot be sufficiently increased. On the contrary, when the amount is too large, the compatibility between the obtained copolymer and the polyester resin becomes poor. This is because not only the initial tack and the adhesive strength become insufficient, but also the holding power decreases.

There is no limitation on the polymerization method, and conventionally known methods such as solution polymerization, emulsion polymerization and bulk polymerization can be appropriately selected and adopted, but the most preferable method is to improve the compatibility. Is a solution polymerization method.

Examples of the polymerization initiator used when the solution polymerization method is adopted include azo compounds such as azobisisobutyronitrile; benzoyl peroxide, dimetatoluyl peroxide, 3-methylbenzoyl peroxide, and deca. Diacyl peroxides such as noyl peroxide; dialkyl peroxides such as di-t-butyl peroxide; hydroperoxides such as t-butyl hydroperoxide; 1,1-bis (t
-Butyl peroxy) Peroxyketals such as 3,3,5-trimethylcyclohexane; Radical polymerization of peroxy esters such as t-butylperoxy-2-ethylhexanoate and t-butylperoxybenzoate The initiator is exemplified as a preferable one. Among these, diacyl peroxides are preferable in order to further improve the compatibility between the polyester resin and the polymerizable unsaturated monomer copolymer.

Examples of the polymerization solvent include toluene, xylene and other high boiling aromatic solvents, ethyl acetate,
Ester solvents such as butyl acetate and cellosolve acetate, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, methyl alcohol, ethyl alcohol,
Examples thereof include alcohol solvents such as propyl alcohol and butyl alcohol, and these can be used as a single solvent or as a mixed solvent.

The pressure-sensitive adhesive resin of the present invention thus obtained is well compatible with the polyester resin coexisting during the polymerization, and is obtained as a uniform solution or emulsion as a whole. Therefore, as it is, or if necessary, add additives such as a filler, a cross-linking agent, a diluent, and an anti-aging agent,
Or, if necessary, after adding a tackifier within a range not deviating from the gist of the present invention, and coating the base paper, plastic film, non-woven fabric or release paper, and drying the mixture, the olefin-based coating is adhered. A pressure-sensitive adhesive layer excellent in adhesive strength to the body, initial tack at low temperature, holding power, etc. is formed.

[0034]

EFFECTS OF THE INVENTION The present invention is constituted as described above, and by adhering a specific polymerizable unsaturated monomer in a polyester resin having a wide molecular weight distribution, the adhesive force to a polyolefin-based adherend, It has become possible to provide a resin for pressure-sensitive adhesives, which has well-balanced performances such as holding power, adhesive strength at low temperature, and initial tack.

[0035]

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited by these examples. In the following examples, "parts" and "%" mean "parts by weight" and "% by weight" unless otherwise specified.

(Production of Polyester Resin) Reference Example 1 In a four-necked flask equipped with a stirrer, a thermometer, an inert gas introducing tube, and a generated water removing device, 404 parts of sebacic acid, 246 parts of 3-methylpentanediol and Dibutyltin oxide
Charge 0.25 parts, stir in an inert gas stream, raise the temperature to 220 ° C., hold for 8 hours to carry out condensation polymerization, acid value 1.
1 polyester resin was obtained. This product had a glass transition temperature of −68 ° C., a weight average molecular weight of 15,000 and a weight average molecular weight / number average molecular weight ratio of 4.3.

Reference Example 2 Adipic acid 278 was added to the same apparatus used in Reference Example 1.
Parts, maleic anhydride 5 parts, 3-methylpentanediol
246 parts and 0.27 part of dibutyltin oxide were charged, stirred under an inert gas stream, heated to 220 ° C. and held for 9 hours to carry out condensation polymerization to obtain a polyester resin having an acid value of 0.4. This had a glass transition temperature of -61 ° C, a weight average molecular weight of 16,000, and a weight average molecular weight / number average molecular weight ratio of 4.8.

Reference Example 3 Adipic acid 292 was added to the same apparatus used in Reference Example 1.
Part, diethylene glycol 106 parts, 1,3-butylene glycol 90 parts, trimethylolpropane 54 parts and dibutyltin oxide 0.33 parts were charged, stirred under an inert gas stream, heated to 220 ° C., and held for 9 hours. Condensation polymerization was performed to obtain a polyester resin having an acid value of 1.5. This product has a glass transition temperature of -43 ° C and a weight average molecular weight of 4
8,000, the weight average molecular weight / number average molecular weight ratio was 12.3.

Reference Example 4 Sebacic acid 343 was added to the same apparatus used in Reference Example 1.
Part, Daimalex resin (polymerized rosin manufactured by Rika Hercules Co., Ltd.) 132 parts, 3-methylpentanediol 246
And 0.25 part of dibutyltin oxide were charged, stirred under an inert gas stream, heated to 220 ° C. and held for 14 hours to carry out condensation polymerization to obtain a polyester resin having an acid value of 4.5. This compound has a glass transition temperature of -38 ° C, a weight average molecular weight of 13,000, and a weight average molecular weight / number average molecular weight ratio of
It was 5.7.

Comparative Reference Example 1c phthalic anhydride 356 was added to the same equipment used in Reference Example 1.
, 1,3-butylene glycol (227 parts) and dibutyltin oxide (0.33 parts) were charged, the mixture was stirred under an inert gas stream, heated to 220 ° C and held for 9 hours to carry out condensation polymerization. Comparison of acid value 4.7 A polyester resin was obtained. The glass transition temperature of this product is 28 ° C, the weight average molecular weight is 11,000,
The weight average molecular weight / number average molecular weight ratio was 4.1.

Comparative Reference Example 2c A comparative polyester resin having an acid value of 16.3 was obtained in the same manner as in Reference Example 1 except that the temperature was raised to 220 ° C. and the holding time at the same temperature was changed to 5 hours. The glass transition temperature of this product is -72.
° C, weight average molecular weight was 7,600, and weight average molecular weight / number average molecular weight ratio was 2.5.

Comparative Reference Example 3c ADEKA CIZER PN-25 was used as a general polymer plasticizer.
0 (polymer plasticizer manufactured by ADEKA ARGUS CORPORATION) was used as a comparative resin. This had a weight average molecular weight of 5,200 and a weight average molecular weight / number average molecular weight ratio of 2.1.

(Production of Pressure-Sensitive Adhesive Sheet) Example 1 139.5 parts of 2-ethylhexyl acrylate, 120 parts of butyl acrylate, 30 parts of vinyl acetate, 9 parts of acrylic acid,
120 parts of 300 parts of a polymerizable unsaturated monomer mixture consisting of 1.5 parts of 2-hydroxyethyl acrylate and Reference Example 1
60 parts of the polyester resin obtained in 1. and 300 parts of ethyl acetate were placed in a four-necked flask equipped with a stirrer, a thermometer, an inert gas introducing tube, a condenser, and a dropping funnel.

The mixture was stirred under a nitrogen stream, and 0.6 part of Niper BMT-K40 (organic peroxide manufactured by NOF CORPORATION) was added as a polymerization initiator at 80 ° C. to initiate the polymerization, and 15 minutes after the initiation of the polymerization, The remaining 180 parts of the polymerizable unsaturated monomer was continuously added dropwise over 2 hours, and after completion of the addition, toluene was added.
0.3 parts of 240 parts and polymerization initiator Niper BMT-K (same as above)
After adding 3 parts and reacting at 85 ° C for 3 hours, the nonvolatile content was 39.7
%, A solution of pressure-sensitive adhesive resin having a viscosity of 5,200 cps was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (isocyanate compound manufactured by Nippon Polyurethane Industry Co., Ltd.) was added as a cross-linking agent, and the thickness after drying was applied onto a polyester film having a thickness of 25 μm. To be 25 μm, and heat-dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet.

Example 2 In Example 1, azobisisobutyronitrile was used in place of the Niper BMT-K40 (same as above), and 0.6 part of azobisisobutyronitrile was added at 75 ° C. to initiate the polymerization. After 15 minutes from the start, the remaining 180 parts of the polymerizable incompatible monomer was continuously added dropwise over 2 hours, and 2 hours after the end of the addition, 240 parts of toluene and 0.3 parts of azobisbutyronitrile as a polymerization initiator were added. A non-volatile content of 40.0% was obtained in the same manner as in Example 1 except that a part was added and the reaction was carried out at 80 ° C. for 3 hours.
%, A solution of a resin for pressure-sensitive adhesive having a viscosity of 4,800 cps was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a crosslinking agent was added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Example 3 In the same manner as in Example 2 except that 60 parts of the polyester resin obtained in Reference Example 2 was used in place of the polyester obtained in Reference Example 1, the nonvolatile content was 39.5% and the viscosity was 39.5%. 12,4
A solution of 00 cps pressure sensitive adhesive resin was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a crosslinking agent was added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Example 4 In the same manner as in Example 1 except that 60 parts of the polyester resin obtained in Reference Example 3 was used in place of the polyester obtained in Reference Example 1, a nonvolatile content of 39.9% and a viscosity were determined. 8,90
A 0 cps solution of pressure sensitive adhesive resin was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a cross-linking agent were added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Example 5 In the same manner as in Example 1 except that 60 parts of the polyester resin obtained in Reference Example 4 was used in place of the polyester obtained in Reference Example 1, a nonvolatile content of 39.8% and a viscosity were obtained. 6,10
A 0 cps solution of pressure sensitive adhesive resin was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a crosslinking agent was added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes. Example 6 In Example 1, as the polymerizable unsaturated monomer mixture,
Nonvolatile content: 39.7%, viscosity: 7, as in Example 1 except that 288 parts of butyl acrylate and 12 parts of acrylic acid were used.
A 200 cps solution of pressure sensitive adhesive resin was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a crosslinking agent was added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Example 7 To 100 parts of the solution of the pressure-sensitive adhesive resin obtained in Example 1, 4 parts of a polymerized rosin ester, pentaline CJ (manufactured by Hercules Co., Ltd.) was added and dissolved, and then used as a crosslinking agent. After adding 2 parts of Coronate L (same as above), it is coated on a 25 μm thick polyester film so that the thickness after drying becomes 25 μm, and heat dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet. It was

Example 8 In the same manner as in Example 1 except that 60 parts of the polyester resin obtained in Reference Example 1 was changed to 20 parts,
A solution of a resin for pressure-sensitive adhesive having a nonvolatile content of 37.2% and a viscosity of 4,800 cps was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a cross-linking agent were added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Example 9 In the same manner as in Example 1 except that 60 parts of the polyester resin obtained in Reference Example 1 was changed to 150 parts,
A solution of a pressure-sensitive adhesive resin having a non-volatile content of 45.3% and a viscosity of 12,800 cps was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a crosslinking agent were added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Example 10 In Example 1, 105 parts of the polyester resin obtained in Reference Example 3 was used in place of the polyester resin obtained in Reference Example 1, and 195 parts of isooctyl acrylate as a polymerizable unsaturated monomer mixture. , Vinyl acetate 60 parts, ethyl acrylate 33 parts, acrylic acid 9 parts, and 2-hydroxyethyl methacrylate 3 parts were used in the same manner as in Example 1 for a pressure-sensitive adhesive having a nonvolatile content of 40.3% and a viscosity of 8,900 cps. A solution of resin was obtained.

To 100 parts of this pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a cross-linking agent was added, and then 2
A pressure-sensitive adhesive sheet was obtained by coating on a polyester film having a thickness of 5 μm so that the thickness after drying was 25 μm, and heat-drying at 100 ° C. for 3 minutes.

Comparative Example 1 Non-volatile content was 35.6% and viscosity was 3100 cp in the same manner as in Example 1 except that the polyester resin was omitted.
A solution of the comparative pressure-sensitive adhesive resin of s was obtained.

To 100 parts of this comparative pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a cross-linking agent was added, and the thickness after drying was 25 μm on a 25 μm thick polyester film. Similarly, it was dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet.

Comparative Example 2 To 100 parts of the solution of the resin for the comparative pressure-sensitive adhesive obtained in Comparative Example 1,
After 7 parts of pentaline C-J (same as above) was added and dissolved,
After adding 2 parts of Coronate L (same as above) as a crosslinking agent,
A pressure-sensitive adhesive sheet was obtained by coating on a 25 μm-thick polyester film so that the thickness after drying would be 25 μm, and thermally drying at 100 ° C. for 3 minutes.

Comparative Example 3 To 100 parts of the solution of the resin for comparative pressure-sensitive adhesive obtained in Comparative Example 1,
After adding 7 parts of the polymer plasticizer described in Comparative Reference Example 3c and adding 2 parts of Coronate L (same as above) as a cross-linking agent, the thickness after drying becomes 25 μm on a polyester film having a thickness of 25 μm. Similarly, it was dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet.

Comparative Example 4 To 100 parts of the solution of the resin for comparative pressure-sensitive adhesive obtained in Comparative Example 1,
10 parts of the polyester resin obtained in Reference Example 1 was mixed,
Both became incompatible with each other.

Comparative Example 5 To 100 parts of the solution of the resin for comparative pressure-sensitive adhesive obtained in Comparative Example 1,
3.5 parts of the pentaline CJ (same as above) and 3.5 parts of the polyester resin obtained in Reference Example 1 were mixed, but they were not compatible and became non-uniform.

Comparative Example 6 A nonvolatile matter was prepared in the same manner as in Example 1 except that 60 parts of the comparative polyester resin obtained in Comparative Reference Example 1c was used in place of the polyester resin obtained in Reference Example 1. A solution of a resin for comparative pressure-sensitive adhesive having a viscosity of 40.0% and a viscosity of 8,200 cps was obtained.

Two parts of Coronate L (same as above) as a cross-linking agent was added to 100 parts of the solution of the comparative pressure-sensitive adhesive resin, and the thickness after drying was 25 μm on a polyester film having a thickness of 25 μm. Similarly, it was dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet.

Comparative Example 7 A nonvolatile matter was prepared in the same manner as in Example 1 except that 60 parts of the comparative polyester resin obtained in Comparative Reference Example 2c was used in place of the polyester resin obtained in Reference Example 1. A solution of a resin for comparative pressure-sensitive adhesive having a viscosity of 40.0% and a viscosity of 8,200 cps was obtained.

To 100 parts of this comparative pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) was added as a cross-linking agent, and then the thickness after drying was 25 μm on a 25 μm thick polyester film. Similarly, it was dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet.

Comparative Example 8 In Example 1, as the polymerizable unsaturated monomer mixture,
2-ethylhexyl acrylate 171 parts, vinyl acetate 1
A solution of a resin for comparative pressure-sensitive adhesive having a nonvolatile content of 33.1% and a viscosity of 8,900 cps was obtained in the same manner as in Example 1 except that 20 parts and 9 parts of acrylic acid were used.

To 100 parts of this comparative pressure-sensitive adhesive resin solution, 2 parts of Coronate L (same as above) as a cross-linking agent was added, and the thickness after drying was 25 μm on a 25 μm thick polyester film. Similarly, it was dried at 100 ° C. for 3 minutes to obtain a pressure-sensitive adhesive sheet.

With respect to the resins for pressure-sensitive adhesives and pressure-sensitive adhesive sheets obtained in the above Examples and Comparative Examples, the compatibility, coating suitability, adhesive strength, initial tack and adhesive holding power were measured by the following methods, The results shown in Tables 1 and 2 were obtained.

[0075] compatibility: A solution of a pressure sensitive adhesive resin was visually observed. ◎ transparent ○ slightly cloudy △ cloudy × incompatible coating suitability: was the coated surface of the pressure-sensitive adhesive sheet visual observation. ◎ Smooth ○ Slightly uneven adhesive strength : Test pressure-sensitive adhesive sheet (25 mm) in an atmosphere of a temperature of 23 ° C. and a humidity of 65%, and an atmosphere of a temperature of 5 ° C.
(Width) is laminated on a polyethylene plate by reciprocating a 2 kg rubber roller once. And 25 minutes later 1
The resistance value when peeled off at a speed of 300 mm / min in the direction of 80 degrees was measured.

Initial tack : temperature of 23 ° C. and humidity of 65%
Of the test pressure-sensitive adhesive sheet attached to the probe tack tester (manufactured by Nichiban Co., Ltd.) in the atmosphere of 5 ° C. and at a temperature of 5 ° C. and peeled off at a contact time of 1 second at a speed of 1 cm / second. Was measured.

Holding power : Stainless steel plate (SUSU30
The pressure-sensitive adhesive test sheet was attached to 4) in an area of 25 mm × 25 mm, and after 20 minutes, a load of 1 kg was applied at 80 ° C. and the time required for dropping was measured.

[0078]

[Table 1]

[0079]

[Table 2]

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Meiwa Baba 5-8 Nishimitabicho, Suita City, Osaka Prefecture Nihon Shokubai Kagaku Kogyo Co., Ltd. Suita Works

Claims (1)

[Claims] 1. The following general formula (1): (However, R ¹ is hydrogen or a methyl group, n is 0 or 1-
5 represents an integer of 5 and R ² has 4 to 1 carbon atoms when n is 0.
2 alkyl groups, and when n is an integer of 1 to 5, each represents an alkyl group having 1 to 5 carbon atoms), or two or more kinds of acrylic acid ester-based monomers: 65 to 99.99
%, And one or more polymerizable unsaturated monomers having a hydroxyl group in the molecule: 0.01 to 5.0% by weight and / or one polymerizable unsaturated monomer having a carboxyl group in the molecule Or 2 or more: a polymerizable unsaturated monomer mixture containing 0.1 to 10.0% by weight as a main polymerizable component, having a glass transition temperature of 0 ° C. or lower, a weight average molecular weight of 10,000 to 1,000,000, and a weight average molecular weight. / A method for producing a resin for pressure-sensitive adhesive, which comprises polymerizing in a polyester resin having a number average molecular weight ratio of 3 or more.