KR102524275B1 - Plasticizer and tacky or adhesive composition for optical applications - Google Patents

Abstract

(purpose)
To provide a plasticizer that does not inhibit monomer polymerization of a heat/active energy ray-curable resin and has long-term heat resistance and excellent initial color/compatibility, which can be suitably used in an optical pressure-adhesive composition.
(solution)
A plasticizer containing rosin ester, wherein the rosin ester is a reaction product of rosin and a monohydric alcohol having 1 to 9 carbon atoms, has a Gardner color number of 1 or less, a glass transition temperature of -15 degrees or less, and an esterification degree of 94 A plasticizer having an abietic acid type resin acid having a conjugated double bond without an aromatic ring and an ester content of less than 10% by weight is used.

Description

Plasticizer and adhesive composition for optical use {PLASTICIZER AND TACKY OR ADHESIVE COMPOSITION FOR OPTICAL APPLICATIONS}

The present invention relates to a plasticizer and an optical adhesive composition.

Conventionally, by adding a plasticizer to various polymer resins, flexibility and elongation of the added resin are increased, or moldability is improved. As such a plasticizer, many kinds of plasticizers, such as adipic acid type, phosphoric acid type, and trimellitic acid type plasticizers, including phthalic acid type plasticizers, such as a phthalic acid diester, are mix|blended. In addition, epoxidized linseed oil and soybean oil having the action of a plasticizer may also be used. In particular, phthalic acid-based plasticizers are widely used as general-purpose plasticizers for polyvinyl chloride (PVC).

However, these plasticizers have problems such as low heat resistance and causing premature deterioration of color and resin over time. In addition, since phthalic acid-based plasticizers may have a harmful effect on human health or the environment, substitutes for phthalic acid-based plasticizers are strongly demanded.

On the other hand, in recent years, active energy rays such as ultraviolet rays have been used from the viewpoints of consideration for the environment and human body and energy saving, as they can be produced with high speed curing at room temperature and solvent-free. A resin that hardens by doing so is used. In particular, it is widely used in the fields of ink, paint, coating, adhesion, and sealing, and also in the field of electronic materials because of its ability to form patterns. In addition, when irradiation of active energy, such as ultraviolet rays, is not possible, a thermosetting resin may be used.

When a conventional plasticizer is used to impart flexibility to a cured product of such a thermosetting/active energy ray curable resin, shrinkage (dimension retention) and yellowing due to curing of the monomer have been problems. In this regard, for example, a compound containing an oxyalkylene group has been proposed as a plasticizer (see Patent Document 1).

However, while inhibiting polymerization inhibition of monomers and enabling high molecular weight of resin, excellent heat resistance and color tone, especially color tone over time (color tone over time), which are important in the fields of paints, adhesives, and electronic materials, etc. A plasticizer and an adhesive composition for optics have not yet been developed.

Japanese Unexamined Patent Publication No. 2012-111843

The present invention provides a plasticizer that does not inhibit monomer polymerization of active energy ray-curable and thermosetting resins, has excellent long-term heat resistance, and has excellent initial color and compatibility in a well-balanced manner, and an optical adhesive composition using the plasticizer. intended to provide

The inventors of the present invention, as a result of repeated intensive studies to develop the above plasticizer and optical adhesive composition, found that the above-mentioned subject could be solved by using a specific rosin ester. The present invention was completed based on these findings.

That is, this invention relates to the plasticizer and optical adhesive composition shown in following claim|item 1-7.

Article 1. As a plasticizer containing a rosin ester,

The rosin ester is a reaction product of rosin and a monohydric alcohol having 1 to 9 carbon atoms, has a Gardner color number of 1 or less, a glass transition temperature of -15 degrees or less, an esterification degree of 94% by weight or more, and an aromatic ring A plasticizer having an abietic acid type resin acid having no conjugated double bond and a content of its ester less than 10% by weight.

Article 2. The plasticizer according to the above item 1, wherein the rosin ester has an acid value of 2 mgKOH/g or less.

Article 3. The plasticizer according to item 1 or 2, wherein the rosin is at least one selected from the group consisting of disproportionated rosin and hydrogenated rosin.

Article 4. The plasticizer according to any one of the above items 1 to 3, wherein the rosin ester contains an abietic acid type resin acid having a conjugated double bond without an aromatic ring and a content of the ester of less than 5% by weight.

Article 5. The plasticizer according to item 4, wherein the content of dehydroabietic acid ester in the rosin ester is 50% by weight or more, or the content of dehydroabietic acid ester is 50% by weight or more.

Article 6. The plasticizer according to item 4 above, wherein the content of tetrahydroabietic acid ester in the rosin ester is 35% by weight or more.

Article 7. An optical adhesive composition containing the plasticizer, curing component, tackifier and polymerization initiator according to any one of the above items 1 to 6.

The plasticizer of the present invention does not inhibit monomer polymerization of active energy ray-curable and thermosetting resins, and has excellent long-term heat resistance. In addition, it has excellent initial color tone and compatibility. Therefore, the plasticizer of this invention can be used suitably for the thermal-active-energy-ray-curable adhesive composition for optics.

The present invention is a plasticizer containing a rosin ester,

The rosin ester is a reaction product of rosin and a monohydric alcohol having 1 to 9 carbon atoms, has a Gardner color number of 1 or less, a glass transition temperature of -15 degrees or less, and an esterification degree of 94% by weight or more. A plasticizer having an abietic acid-type resin acid having a conjugated double bond without an aromatic ring and a content of its ester of less than 10% by weight.

As the rosin, which is a component of the rosin ester, known various rosins can be used without particular limitation. As rosin, for example, natural rosin such as gum rosin including Indonesian gum rosin, tall oil rosin, wood rosin, and purified natural rosin Refined rosin obtained by grinding, hydrogenated rosin obtained by hydrogenating natural rosin, disproportionated rosin obtained by disproportionation of natural rosin, and the like are exemplified. As rosins, more preferred are disproportionated rosin and hydrogenated rosin. By using these, the Gardner color number of 1 or less of the adhesive composition obtained becomes easy to obtain, and the heat resistance of a plasticizer and the adhesive agent composition for optics can be improved more.

The purified rosin can be obtained using various known methods such as distillation, extraction, and recrystallization. In the distillation method, the natural rosin can be distilled under a reduced pressure of about 0.01 to 3 kPa at a temperature of about 200 to 300 degrees, for example. In the extraction method, purified rosin can be obtained by, for example, making the natural rosin into an alkaline aqueous solution, extracting insoluble insoluble substances (unsaponifiable substances) with various organic solvents, and then neutralizing the water layer. In the recrystallization method, for example, the natural rosin is dissolved in an organic solvent as a good solvent, and then the solvent is distilled off (distilled off) to obtain a thick solution, and a poor solvent Refined rosin can be obtained by adding an organic solvent as a solvent.

The said disproportionated rosin can be obtained using various well-known means. For example, disproportionated rosin can be obtained by subjecting raw material natural rosin or refined purified rosin to a heating reaction in the presence of a disproportionation catalyst. Examples of the disproportionation catalyst include supported catalysts such as palladium-carbon, rhodium-carbon, and platinum-carbon; metal powders such as nickel and platinum; Various known ones such as iodides such as iodine and iron iodide can be used. The amount of the catalyst used is usually about 0.01 to 5 parts by weight, preferably about 0.01 to 1 part by weight, based on 100 parts by weight of rosin. The reaction temperature is about 100 to 300 degrees, preferably about 150 to 290 degrees. Further, the disproportionated rosin is preferably purified by the distillation method from the viewpoint of improving heat resistance.

The hydrogenated rosin can be obtained by hydrogenating rosin under known hydrogenation conditions. Specifically, for example, hydrogenation is performed by heating rosin at about 2 to 20 MPa or about 100 to 300 degrees in a hydrogen atmosphere in the presence of a hydrogenation catalyst. The reaction pressure is preferably about 5 to 20 MPa. The reaction temperature is preferably about 150 to 300 degrees. As the hydrogenation catalyst, various known ones such as supported catalysts, metal powders, iodine, and iodides can be used. Examples of supported catalysts include palladium-carbon, rhodium-carbon, ruthenium-carbon, and platinum-carbon. As a metal powder, nickel, platinum, etc. are mentioned. As an iodide, iron iodide etc. are mentioned. Among these, palladium, rhodium, ruthenium, and platinum-based catalysts are preferable because the hydrogenation rate of rosin is high and the hydrogenation time is short. In addition, the amount of hydrogenation catalyst used is usually about 0.01 to 5 parts by weight, preferably about 0.01 to 2 parts by weight, based on 100 parts by weight of rosin.

In order to obtain the rosin ester, it is essential to use a monohydric alcohol having 1 to 9 carbon atoms as the alcohol. When a monohydric alcohol having more than 9 carbon atoms is used, the heat resistance of the obtained rosin ester tends to decrease. When an alcohol other than monohydric is used, there is a problem that the viscosity of the obtained rosin ester increases, the fluidity decreases, and the plasticity is insufficiently maintained. Among the above-mentioned monohydric alcohols having 1 to 9 carbon atoms, monohydric alcohols having 1 to 8 carbon atoms can be preferably used because of their excellent adhesive strength when used as a plasticizer and an optical point-and-adhesive composition. Specific examples of the monohydric alcohol having 1 to 8 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-butanol, sc-butanol, trc-butyl alcohol, n-octyl alcohol, and 2-ethylhexyl alcohol. . These can be used individually by 1 type or in combination of 2 or more types. More preferably, it is a C1-C4 monohydric alcohol, Most preferably, it is a C1 monohydric alcohol, ie, methanol.

The rosin ester has a Gardner color number of 1 or less, and preferably a Hazen color number of 200 H or less. When the Gardner color number of the rosin ester is 1 or less, not only the initial color tone of the plasticizer and the active energy ray-curable adhesive composition for heat and optical use is excellent, but also the long-term heat resistance is excellent. The Gardner color number and the Hazen color number are measured in Gardner units and Hazen units, respectively, according to JIS K 0071.

The rosin ester has a glass transition temperature (Tg) of -15 degrees or less. Since the glass transition temperature of the rosin ester is -15 degrees or less, it is possible to prevent a decrease in low-temperature adhesive strength without increasing the Tg of the adhesive composition for optical use. The glass transition temperature is preferably -15 degrees to -35 degrees. The glass transition temperature is measured by the method specified in JIS K 7121.

The rosin ester has an esterification degree of 94% by weight or more, preferably 97 to 100% by weight. Here, the degree of esterification is determined by the ratio between the total peak area of the rosin ester measured by gel permeation chromatography (GPC) and the peak area corresponding to the monoester in the ester. The higher the degree of esterification, the smaller the initial color tone and the change in color tone due to heating, and the better. Specifically, it is calculated by the following formula (1). When the rosin ester has a degree of esterification of 94% by weight or more, the plasticizer has excellent initial color tone and long-term heat resistance.

Esterification degree of rosin ester (%) = [A/sum of all peak areas] × 100 (1)

In formula (1), A represents the peak area (peak area corresponding to the monoester form in rosin ester) at a weight average molecular weight (value in terms of polystyrene) of 240.

In the rosin ester, the content of an abietic acid-type resin acid having a conjugated double bond without an aromatic ring and an ester thereof is less than 10% by weight. When it is 10% by weight or more, polymerization inhibition of the thermosetting component and the active energy ray curing component cannot be suppressed, and the polymerization rate is lowered. As a result, it becomes difficult to obtain a high molecular weight thermosetting type and active energy ray curable type resin. It is preferably less than 5% by weight, more preferably substantially less than 0% by weight (to an undetectable level). The content is measured by gas chromatograph analysis (GC). Rosin ester undergoes the following pretreatment, prepares a solution, and measures GC under the following conditions.

(Sample pretreatment method)

10 mg of rosin ester was precisely weighed (precisely weighed; precisely measured), and 2 mL of a mixture of MOE/toluene (50/50) was added to dissolve. A 10% hexane solution of trimethylsilyldiazomethane is added dropwise, the sample is methyl esterified and analyzed.

(GC measurement condition)

Type : AGCｌｅｎｔ 6890 Ｓｅｒｉｅｓ

Column: BDS (manufactured by SUCCO) 0.3 mm Φ × 25 m, film thickness 0.25 μm

Detector: Hydrogen salt ionization detector (FID)

Column temperature: 190 degrees for 30 minutes

Inlet temperature: 250 degrees

Detector temperature: 280 degrees

Carrier gas: N2 100kPa, 2.2mL/mn

Split ratio: 50/1

Injection amount: 1.0μL

Abietic acid-type resin acids having a conjugated double bond without an aromatic ring include abietic acid and its isomers. Examples of isomers of abietic acid include neoabietic acid, levopimaric acid, and palustric acid, but dehydroabietic acid having an aromatic ring is not included. . Further, pimaric acid-type resin acids such as pimaric acid, isopimaric acid, and sandaracopimaric acid are not included.

The method for producing the rosin ester is not particularly limited, and a known esterification method can be employed. The amount of rosin and alcohol added is not particularly limited, but is usually determined so that the OH group of alcohol / COOH group (equivalent ratio) of rosin is in the range of about 0.8 to 8, preferably about 3 to 7 do. The reaction temperature of the esterification reaction is usually about 150 to 320 degrees, preferably about 150 to 300 degrees. The reaction time is usually about 2 to 24 hours, preferably about 2 to 7 hours. In addition, for the purpose of shortening the reaction time, the esterification reaction may proceed in the presence of a catalyst. Examples of the catalyst include acid catalysts such as p-toluenesulfonic acid; metal hydroxides such as calcium hydroxide and magnesium hydroxide; Metal oxides, such as calcium oxide and magnesium oxide, etc. are mentioned. Since water is produced as a result of the esterification reaction, the reaction can proceed while removing the produced water out of the system. Considering the color tone of the obtained rosin ester, it is preferable to carry out the reaction under an inert gas stream. This reaction can be carried out under pressure as needed. It is also possible to carry out the reaction in an organic solvent that is non-reactive with respect to rosin and alcohol. Examples of the organic solvent include hexane, cyclohexane, toluene, and xylene. Moreover, when an organic solvent is used, if it is necessary to distill off the solvent or unreacted raw materials, it can be suitably carried out under reduced pressure.

When purified rosin, disproportionated rosin, or hydrogenated rosin is used as rosin, natural rosin is purified, disproportionated, or hydrogenated after esterification of natural rosin and alcohols, or natural rosin is purified or hydrogenated. It is possible to esterify rosin and alcohol obtained by equalization or hydrogenation.

As the rosin ester used in the present invention, it is preferable to use one having an acid value of 2 mgKOH/g or less. A more preferable acid value is 1 mgKOH/g or less. Thereby, heat resistance improves. An acid value is measured according to JIS K0070.

Among the rosin esters used in the present invention, it is preferable that the content of dehydroabietic acid ester is 50% by weight or more or the content of dehydroabietic acid ester is 50% by weight or more. In this way, inhibition of polymerization of the heat/active energy ray-curable component can be further suppressed, and a heat/active energy ray-curable type resin having plasticity and high molecular weight can be formed.

Among the rosin esters used in the present invention, the tetrahydroabietic acid ester content is preferably 35% by weight or more, and more preferably 90% by weight or more. In this way, the polymerization inhibition of the active energy ray-curing component can be further suppressed, and the polymerization rate can be improved. Therefore, it is possible to form a heat/active energy ray-curable resin having plasticity and having a higher molecular weight.

The plasticizer and optical adhesive composition of the present invention can be obtained using the above rosin ester. Since the plasticizer and the adhesive composition for optics of the present invention are excellent in heat resistance, they can be suitably used in applications in which heat resistance is important. For example, hot-melt type adhesives used for packaging, bookbinding, and attachment in disposable diapers or sanitary products in which coloration with age at high temperatures is important; Optical plasticizers and adhesives for optics added to optical resins for which transparency is important, such as OCC (OCC), ACAC, and OCA (OCC) ｌｙＣｌｅａｒ Ｒｅｓｉｎ); It can be suitably used for adhesives and adhesives for films. The content of the rosin ester is preferably about 1 to 100 parts by weight based on 100 parts by weight of the composition. By setting the content of the rosin ester within this range, the effect of improving plasticity and adhesive performance by adding the rosin ester is expressed. A more preferable content is about 1 to 40 parts by weight.

The plasticizer of the present invention may contain other additives in addition to the above rosin esters within a range not impairing the effects of the present invention. Examples of other additives include antioxidants, polymerization inhibitors, and sensitizers. Other additives are preferably 0.5 to 10 parts by weight based on 100 parts by weight of the plasticizer.

An optical pressure-adhesive composition containing a plasticizer, a curing component, a tackifying resin, and a polymerization initiator of the present invention is also one of the present invention. The curing component includes a thermosetting component and an active energy ray curing component.

As the thermosetting component, a thermosetting resin such as an epoxy resin, a phenol resin, an unsaturated polyester resin, a urea resin, a melamine resin, a diallyl phthalate resin, a silicon resin, a vinyl ester resin, a polyimide resin, a polyurethane resin, etc. It will not specifically limit if it can form, It can use 1 type or in combination of 2 or more types. Specifically, "Compoceran", "ARACOAT", and "ARAKYD" manufactured by Arakawa Chemical Industries, Ltd. are exemplified.

Examples of the active energy ray-curing component include compounds curable by active energy rays (electron beams, ultraviolet rays, etc.) such as monomers, oligomers and polymers.

Specific examples of the monomer and oligomer include butyl acrylate, butadiene acrylate, urethane acrylate, silicone acrylate and epoxy acrylate. A monomer is also called a monomer and is a raw material in the case of synthesizing a polymer by a curing reaction. Oligomers are also called oligomers, and have a relatively low polymerization degree of about 2 to 20, but are raw materials in the case of synthesizing a polymer by a curing reaction.

As the polymer, various known polymers can be used without particular limitation as long as they are compounds capable of radically polymerizing with active energy rays such as ultraviolet rays or electron beams to form a cured film. Specifically, polyacryl acrylate, polyurethane acrylate, polyester acrylate, etc. (for example, Arakawa Chemical Industry Co., Ltd. "beam set series") are mentioned.

The tackifier is not particularly limited as long as it is generally used as a tackifying resin, and examples thereof include petroleum resins, phenolic resins, xylene resins, coumarone resins, rosin-based resins, and terpene-based resins. ) resin, hydrogenated petroleum resin, hydrogenated rosin-based resin, hydrogenated terpene-based resin, etc. can be used. Among them, it is preferable that the color tone is Gardner color number 1 or less. As a thing whose color tone is Gardner color number 1 or less, hydrogenated petroleum resin and hydrogenated rosin-type resin are mentioned, for example. Since these hydrogenated resins usually have a Gardner color number of 1 or less, they are tackifiers excellent in transparency and improve the transparency of the pressure-sensitive adhesive for optics and the pressure-sensitive adhesive layer. In addition, since these hydrogenated resins are less likely to inhibit polymerization during polymerization by thermal curing or irradiation with active energy rays such as ultraviolet rays, use of these hydrogenated resins results in optical adhesives with excellent curability. These can use 1 type or 2 or more types. Specifically, hydrogenated rosin-type resins of the Fine Crystal series (Fine Crystal KE-311, Fine Crystal KE-100, etc.) of Arakawa Chemical Industry Co., Ltd. are mentioned, for example. Among these, the use of KE-311, which has a particularly good color tone and low polymerization inhibitory property, is preferable. More preferably, it is a completely hydrogenated rosin-type resin. Fully hydrogenated rosin ester is very suitable as an optical tackifier because it has completely colorless initial color, excellent aging stability, and good heating stability. Therefore, the pressure-sensitive adhesive composition using the fully hydrogenated rosin ester and the plasticizer of the present invention as a tackifier can not only suppress the inhibition of polymerization of the base resin included in the pressure-sensitive adhesive composition, but also impart plasticity. Since it can be used as a point-adhesive having excellent color tone and stability over time, it is suitable as an point-and-adhesive composition for optics.

The polymerization initiator is not particularly limited as long as it can initiate polymerization by generating radicals by heat and active energy rays, and known ones can be used. As the photopolymerization initiator, for example, benzophenone, benzyl, Michler's ketone, thioxanthone, anthraquinone, etc., a type compound that generates radicals by hydrogen extraction. However, compounds of a type that generate radicals by intramolecular cleavage, such as benzoin, dialkoxyacetophenone, acyloxime ester, benzyl ketal, hydroxyalkylphenone, and halogenoketone, can be appropriately selected and employed. Examples of the polymerization inhibitor include hydroquinone, benzoquinone, toluhydroquinone, and paratertiary butyl catechol. Examples of photosensitizers include amines such as aliphatic amines and aromatic amines, urea such as o-tolylthiourea, sodium diethyldithiophosphate, and s-benzylisothiourea-p- Sulfur compounds, such as toluenesulfonate, etc. are mentioned. These can be used individually or in combination of 2 or more types. In particular, from the viewpoint of handling properties and compatibility due to non-yellowing, 2-hydroxy-2-methyl-1-phenyl-propan-1-one is preferable.

The optical pressure-sensitive adhesive composition of the present invention can be prepared by mixing the plasticizer, the curing component, and the tackifying resin in the following ratio at a temperature of 10 to 70 degrees under atmospheric pressure, and then adding the polymerization initiator.

The ratio (solid weight parts) of the optical adhesive composition containing the plasticizer, the curing component, the tackifying resin and the polymerization initiator in the optical adhesive composition of the present invention is 1 to 60:40 to 98:1 It is preferably -60:0.1-10. More preferably, it is 1 to 40:60 to 95:1 to 40:0.5 to 8.

Examples of the type of the adhesive composition include an acrylic adhesive composition, a styrene-conjugated diene block copolymer adhesive composition, and an ethylene hot melt adhesive composition. Among these, acrylic point-and-adhesive compositions are preferred because of their excellent heat resistance and the ability to control adhesive strength in a wide range.

The acrylic adhesive composition of the present invention contains the above rosin ester and acrylic polymer. The acrylic adhesive composition can be obtained, for example, by blending a rosin ester with an acrylic polymer as a base polymer. The content of the acrylic polymer is preferably about 1 to 50 parts by weight based on 100 parts by weight of the composition. By setting the content of the acrylic polymer within this range, the effect of improving the plasticity performance by adding the rosin ester is expressed. A more preferable content is about 1 to 40 parts by weight.

The acrylic polymer is not particularly limited, and various known homopolymers or copolymers used as the acrylic pressure-sensitive adhesive composition can be used as they are. As the monomer used for the acrylic polymer, various (meth)acrylic acid esters ("(meth)acrylic acid ester" is the meaning of acrylic acid ester and/or methacrylic acid ester, and the following "(meth)acrylic acid" is also synonymous). can be used Specific examples of such (meth)acrylic acid esters include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. These can be used individually by 1 type or in combination of 2 or more types. In addition, in order to impart polarity to the obtained acrylic polymer, a small amount of (meth)acrylic acid may be used in place of a part of the above (meth)acrylic acid ester. In addition, as a crosslinkable monomer, glycidyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N-methylol (meth)acrylamide and the like can be used in combination. Further, if desired, other copolymerizable monomers such as vinyl acetate and styrene may be used in combination to the extent that the adhesive properties of the (meth)acrylic acid ester polymer are not impaired. As the polymerization method, various known methods can be used. In addition to using a general radical polymerization method, methods such as a cationic polymerization method, a living radical polymerization method, and a living anionic polymerization method can be used.

The glass transition temperature of the acrylic polymer containing (meth)acrylic acid ester as a main component is not particularly limited, and is usually in the range of -90 to 0 degrees, preferably -80 to -10 degrees. When the glass transition temperature is too high than 0 degrees, the adhesive strength tends to decrease, and when it is too low than -90 degrees, the adhesive strength tends to decrease. In addition, the molecular weight of the acrylic polymer is not particularly limited, and usually the weight average molecular weight is about 50,000 to 2,000,000, preferably about 100,000 to 1,000,000. By making molecular weight into this range, adhesiveness becomes favorable. In addition, a weight average molecular weight is a standard polystyrene conversion value measured by gel permeation chromatography (GPC).

As the method for producing the acrylic polymer, various known methods may be employed. As a method for producing the acrylic polymer, for example, a radical polymerization method such as bulk polymerization method, solution polymerization method, or suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various well-known azo-based and peroxide-based ones can be used. The reaction temperature is usually about 50 to 85 degrees. The reaction time is about 1 to 8 hours. As the solvent for the acrylic polymer, solvents such as ethyl acetate and toluene are generally used, and the concentration of the solution is preferably about 40 to 60% by weight.

In the acrylic adhesive composition of the present invention, a crosslinking agent such as polyisocyanate, polyamine, melamine resin, urea resin, or epoxy resin may be added to the acrylic polymer and tackifying resin. Cohesive force and heat resistance can be further improved by adding a crosslinking agent. Among these crosslinking agents, polyisocyanate is particularly preferably used. As polyisocyanate, a conventionally well-known thing can be widely used. Specific examples thereof include 1,6-hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate, and 4,4-diphenylmethane diisocyanate. In addition, additives such as fillers, antioxidants, and ultraviolet absorbers may be appropriately used in the acrylic adhesive composition of the present invention, if necessary. In addition, various known tackifying resins other than the above-mentioned rosin ester may be used together in the acrylic adhesive composition of the present invention within a range not departing from the object of the present invention.

The styrene-conjugated diene-based block copolymer adhesive agent composition contains the rosin ester and the styrene-conjugated diene-based block copolymer.

The styrene-conjugated diene-based block copolymer is a block copolymer obtained by copolymerizing styrenes such as styrene and methylstyrene with conjugated dienes such as butadiene and isoprene, appropriately selected according to the purpose of use. Usually, the weight ratio of styrene/conjugated diene is 10/90 to 50/50. Preferable specific examples of such a block copolymer include, for example, a SBS type block copolymer in which the weight ratio of styrene (S)/butadiene (B) is in the range of 10/90 to 50/50, styrene (S)/isoprene ( and SiS type block copolymers in which the weight ratio of I) is in the range of 10/90 to 30/70. Moreover, what hydrogenated the conjugated diene component of the said block copolymer is contained in the styrene-conjugated diene system block copolymer. Specific examples of hydrogenated materials include so-called SES type block copolymers and SES type block copolymers.

Additives such as oil, tackifier, filler, and antioxidant may be added to the styrene-conjugated diene-based block copolymer pressure-sensitive adhesive composition, if necessary.

The ethylene-based hot-melt adhesive composition contains an ethylene-based copolymer and the rosin ester.

The above ethylene-based copolymer is a copolymer of ethylene and a monomer copolymerizable with ethylene, and those conventionally used for hot melt adhesives can be used. As a monomer copolymerizable with ethylene, vinyl acetate etc. are mentioned, for example. The content of vinyl acetate is usually about 20 to 45% by weight. Further, the melt index (190 degrees, load 2160 g, 10 minutes) of the ethylenic copolymer is preferably about 10 to 400 g/10 minutes.

Further, additives such as wax, tackifier, filler, and antioxidant may be added to the ethylene-based hot-melt adhesive composition, if necessary.

[Example]

Hereinafter, the method of the present invention will be described in more detail by giving Examples and Comparative Examples, but the present invention is not limited thereto. In Examples, "%" indicates "% by weight", and "part" indicates "part by weight".

Production Example 1 (Production of Rosin Ester 1)

100 g of Chinese disproportionated rosin (manufactured by Guangxi Wuzhou Arakawa Chemical Industries, Ltd) and 300 g of methanol were placed in a 1 L autoclave, and the temperature was raised to 290 degrees after removing oxygen in the system. The internal pressure of the autoclave reached a maximum of 14 MPa. Esterification was carried out for 2 hours while depressurization was performed every 20 minutes to discharge water vapor. After concentrating the obtained reaction liquid with a rotary evaporator, 5 g of calcium hydroxide was added, and by simple distillation under conditions of a liquid temperature of 150 to 270 degrees and a pressure of 0.4 kPa, the main ) 68 g of rosin ester 1 was obtained as a fraction.

Production Example 2 (Production of Rosin Ester 2)

Rosin ester 2 in the same manner as in Production Example 1, except that Chinese disproportionated rosin was replaced with Chinese hydrogenated rosin (manufactured by Wuzhou Sun Shine Forestry and Chemicals Co., Ltd. of Guangxi). 65 g was obtained.

Production Example 3 (Production of Rosin Ester 3)

In Production Example 1, 66 g of rosin ester 3 was obtained in the same manner except that Chinese disproportionated rosin was replaced with distilled disproportionated rosin (manufactured by Arakawa Chemical Industry Co., Ltd.).

Production Example 4 (Production of Rosin Ester 4)

100 g of rosin ester 3 obtained in Production Example 3 and 100 g of 2-propanol were added to a 300 ml flask equipped with a stirrer, a cooling tube and a nitrogen inlet tube, and the temperature was raised to 40 degrees to dissolve, and then the vessel was immersed in a constant temperature circulator. The temperature was lowered from 40 degrees, and a seed crystal was introduced in the middle. After the cotton-like white crystals rapidly increased, the temperature of the apparatus was lowered to 5 degrees and maintained for 1.5 hours. Thereafter, in the suction filtration, the crystals were washed with 1/3 to 1/2 times the amount of 2-propanol charged as the raw material, and subsequently dried at 50 degrees and 10 Tlor for 2 hours under reduced pressure to obtain 49 g of rosin ester 4.

Production Example 5 (Production of Rosin Ester 5)

100 g of rosin ester 3 obtained in Production Example 3 and 100 g of 2-propanol were added to a 300 ml flask equipped with a stirrer, a cooling tube and a nitrogen inlet tube, heated to 40 degrees to dissolve, and then the vessel was immersed in a constant temperature circulator. The temperature was lowered from 40 degrees, and seed crystals were introduced on the way. After the white crystals in the form of planes rapidly increased, the temperature of the apparatus was lowered to 5 degrees and held for 1.5 hours. Thereafter, in the suction filtration, the crystals are washed with 1/3 to 1/2 times the amount of 2-propanol charged as the raw material, and subsequently dried at 50 degrees and 10 Tlor for 2 hours under reduced pressure. 28 g of rosin ester 5 was obtained by repeating the above-mentioned recrystallization operation twice more with respect to the obtained crystals.

Production Example 6 (Production of Rosin Ester 6)

64g of rosin ester 6 was obtained in the same manner as in Production Example 1, except that the Chinese disproportionated rosin was replaced with a highly hydrogenated rosin (made by FCOCC, LCCO, LTP).

Production Example 7 (Production of Rosin Ester 7)

Distilled hydrogenated rosin (distillate of hydrogenated rosin; product of Arakawa Chemical Industry Co., Ltd., dihydroabietic acid: 68.9%, tetrahydroabietic acid: 20.6%) 500g and palladium/carbon catalyst 5C-50W (N E 15 g of Chemcat Co., Ltd. (manufactured by N.E. CHEMCAT Corporation, 50% product (containing water)) was placed in a 1 L flask, and after N2 sealing, the temperature was raised to 190 degrees and dehydrated for 1 hour. Next, the molten material was transferred to a 2 L autoclave, diluted with 500 g of methylcyclohexane, and hydrogenated for 3 hours under conditions of 7 to 10 MPa and 150 to 300 degrees. After the catalyst was removed by filtration, the reaction solution was transferred to a 1 L flask, heated to 200 degrees to remove methylcyclohexane, and thereafter distilled under reduced pressure at 15 mmHg for 30 minutes. Thereafter, the above reaction liquid and 1500 g of methanol were put into a 5 L autoclave, and after removing oxygen in the system, the temperature was raised to 290 degrees, the pressure was reduced every 20 minutes, and esterification was carried out for 2 hours while discharging water vapor. At that time, the internal pressure of the autoclave reached a maximum of 14 MPa. After concentrating the obtained reaction liquid in a rotary evaporator, 25 g of calcium hydroxide was added, and 60 g of rosin ester 7 was obtained as a main fraction by simple distillation under conditions of a liquid temperature of 150 to 270 degrees and a pressure of 0.4 kPa.

Production Example 8 (Production of Rosin Ester 8)

51 g of rosin ester 8 was obtained by adding 48 g of rosin ester 2 and 3 g of rosin ester 11 described later to a 200 ml beaker, and stirring in a water bath at 70 degrees for 30 minutes.

Preparation Example 9 (Preparation of Rosin Ester 9)

51 g of rosin ester 9 was obtained by adding 45 g of rosin ester 2 and 6 g of rosin ester 11 described later to a 200 ml beaker, and stirring in a water bath at 70 degrees for 30 minutes.

Production Example 10 (Preparation of Rosin Ester 10)

70 g of rosin ester 10 was obtained in the same manner as in Production Example 1, except that methanol was changed to 2-ethylhexanol.

Comparative Preparation Example 1 (Preparation of Rosin Ester 11)

In Production Example 1, 65 g of rosin ester 11 was obtained in the same manner as in Production Example 1, except that Chinese disproportionated rosin was replaced with Chinese gum rosin (manufactured by Guangxi Wuzhou Arakawa Chemical Industry Co., Ltd.).

Comparative Preparation Example 2 (Preparation of Rosin Ester 12)

71 g of rosin ester 12 was obtained in the same manner as in Production Example 1, except that methanol was changed to n-decanol.

Comparative Preparation Example 3 (Preparation of Rosin Ester 13)

37 g of rosin ester 2 and 13 g of rosin ester 11 were added to a 200 mL beaker, and 50 g of rosin ester 13 was obtained by stirring in a water bath at 70 degrees for 30 minutes.

Also, as the rosin ester 14, Hercoline D (hydrogenated rosin methyl ester, manufactured by Estmn Co., Ltd.) was used.

The physical properties of the rosin esters 1 to 14 were measured as follows. The results are shown in Table 1. Melting point and glass transition temperature (Tg): measured by differential scanning calorimetry (heat flux DC) specified in JIS K 7121.

DSC measuring device: DSC8230B manufactured by Rigaku Corporation

Color tone: According to JIS K 0071, it was measured in Gardner units and Hazen units.

Acid value: measured according to JIS K0070.

<Calculation of degree of esterification>

Rosin esters 1 to 14 were dissolved in tetrahydrofuran to prepare a 0.5% solution. About this solution, GPC measurement was carried out under the following conditions, and the degree of esterification was calculated from the following formula (1).

(GPC measurement conditions)

Model: Product name "HC-8220", manufactured by Tosoh Corporation

Column: Product name "TSKIGIL G2500HL", one product from Tosoh Co., Ltd.

Product name 「TSKIGIL G2000ＨＸＬ」, Tosoh Co., Ltd. product 2 pieces and

Product name 「TSKIGIL G1000ＨＸＬ」, product of Tosoh Co., Ltd. 1 connection

Developing solvent flow rate: tetrahydrofuran, 1㎖/min

Measurement temperature: 40 degrees

Detector: RII

Degree of esterification of rosin esters 1 to 14 (%) = [A/sum of all peak areas] × 100 ... (1)

In Formula (1), A represents the peak area (peak area corresponding to the monoester form of rosin esters 1 to 14) at a weight average molecular weight (value in terms of polystyrene) of 240.

<Analysis of rosin ester composition ratio>

Regarding the analysis of the composition ratio of the rosin component (resin acid component) in the rosin ester in the present invention, it was analyzed by gas chromatograph analysis (GC). The rosin ester was subjected to the following pretreatment, the solution was adjusted, and GC measurement was performed under the following conditions. The results are shown in Table 2.

(Sample pretreatment method)

10 mg of rosin ester was precisely weighed and dissolved by adding 2 mL of a mixture of methanol/toluene (50/50). A 10% hexane solution of trimethylsilyldiazomethane was added dropwise, the sample was methyl esterified and analyzed.

(GC measurement conditions)

Type : AGCｌｅｎｔ 6890 Ｓｅｒｉｅｓ

Column: BDS (manufactured by SUCCO) 0.3 mm Φ × 25 m, film thickness 0.25 μm

Detector: Hydrogen salt ionization detector (FID)

Column temperature: 190 degrees for 30 minutes

Inlet temperature: 250 degrees

Detector temperature: 280 degrees

Carrier gas: N2 100kPa, 2.2mL/mn

Split ratio: 50/1

Injection volume: 1.0μL

The composition ratio of the rosin ester was calculated separately for each of the following retention times (hereinafter also referred to as RT).

Neutral component: peak detected at RT 0 to 4.1 minutes

Tetrahydroabietic acid ester: Among the peaks detected at 4.1 to 10 minutes of RT, the peaks detected at 4.6 minutes, 5.1 minutes, 5.3 minutes, 5.6 minutes, 5.8 minutes, 6.0 minutes, 6.1 minutes, 6.4 minutes, and 7.0 minutes

Dihydroabietic acid ester: Among the peaks detected at RT 4.1 to 10 minutes, those other than tetrahydroabietic acid ester

Abietic acid ester: peak detected at RT 11.2 minutes

Dehydroabietic acid ester: peak detected at RT 11.7 minutes

<Various performance evaluation>

Examples 1 to 10, Comparative Examples 1 to 5

Rosin esters 1 to 14 were used as plasticizers, respectively, and polymerization inhibitory properties, heat resistance and adhesive strength were evaluated. In addition, conditions in which no plasticizer was used were described in Comparative Example 1. The results are shown in Table 4.

<Evaluation of polymerization inhibition rate>

Samples for evaluation of polymerization inhibitory properties were prepared as follows. After dissolving 78 parts of butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.), 2 parts of Irgacure 1173 (manufactured by BASF) and 20 parts of plasticizer (rosin ester 1) , 2 ml was taken out into an aluminum cup and used as a sample for evaluation of polymerization inhibition. In addition, the plasticizer was changed as shown in Table 3, and the same evaluation samples were also prepared.

About the polymerization inhibitory property of the plasticizer in this invention, the polymerization rate and weight average molecular weight were computed and evaluated by GPC. Details are described below.

The obtained sample was placed in a UV irradiation box (manufactured by JATEC), and irradiated with a high-pressure mercury lamp for 30 seconds from a UV irradiation device (TOSHIBA LIGHTING & TECHNOLOGY CORPORATION, TOSHIBA LIGHTING & TECHNOLOGY CORPORATION, TOSHIBA LIGHTING & TECHNOLOGY CORPORATION) for 30 seconds. . After irradiation for 10 seconds and 30 seconds, samples were taken to measure GPC.

(GPC measurement condition)

Model: Product name "HC-8220", manufactured by Tosoh Co., Ltd.

Column: Product name "TSKGEI" x 3 pieces

Developing solvent flow rate: tetrahydrofuran, 0.6 ml/min

Measurement temperature: 40 degrees

Detector: RII

(polymerization rate)

Polymerization rate (%) = P / (P + M) ... (2)

P: GPC peak area ratio of acrylic polymer (peak detected at retention time 8 to 13 minutes)

M: GPC peak area ratio of acrylic monomer (peak detected at retention time of 15.5 to 16.5 minutes)

The higher the polymerization rate is, the lower the polymerization inhibitory property is.

(weight average molecular weight)

Weight average molecular weight = (Mp×P + Mm×M) / (P+M) ... (3)

MP: weight average molecular weight of the acrylic polymer part

MM: Weight average molecular weight of the acrylic monomer part

The higher the weight average molecular weight is, the lower the polymerization inhibitory property is.

The results of polymerization rate and weight average molecular weight are shown in Table 4.

<Heat Resistance>

5 g of rosin ester 1 was collected in a glass test tube (outer diameter: 15 mm, length: 150 mm, thickness: 10 mm), and the test tube was left standing in a hot air circulation dryer at 95 degrees for 10 days while standing vertically on the test tube stand. The color tone before heating and after heating for 10 days was evaluated in Gardner units. Moreover, when it did not satisfy 1 Gardner, it evaluated by the Hazen color number. Also, rosin esters 2 to 14 were evaluated in the same manner.

<Interface Adhesion>

(Preparation of adhesive composition for optical use)

26.5 parts of urethane acrylate (trade name "UA-160TM", manufactured by Shin Nakamura Chemical Co., Ltd.), as a monomer, dodecyl acrylate (LA, manufactured by Wako Pure Chemical Industries, Ltd.) ) 19.9 parts and isobornyl acrylate (IAXA, manufactured by Tokyo Chemical Industry Co., Ltd.) 12.4 parts, plasticizer (rosin ester 1) 40.0 parts, Irgacure TPO as a photoinitiator (BASF Co., Ltd.) Product) 0.3 part and Irgacure 184 (product of BASF Co.) 0.9 part were added and dissolved. Also, samples for evaluation were similarly prepared for rosin esters 2 to 14.

(Preparation of test piece)

Two glass plates (76 mm × 26 mm × 1.2-1.5 mm, Matsunami Glass Ind., Ltd.) were prepared, a 150 μm PET film was placed as a spacer on one glass plate, and the other glass plate A small amount of the adhesive agent composition for optics prepared from rosin ester 1 was dropped at the center of, and two glass plates were bonded crosswise. The amount of the sample was adjusted so that the adhesive surface to which the pressure-sensitive adhesive composition was bonded had a diameter of about 10 mm in order to prevent protrusion or sticking to the spacer. Thereafter, using a high-pressure mercury lamp, ultraviolet rays were irradiated at an illuminance of 150 mJ/cm ² and a cumulative light amount of 3,000 mJ/cm ² to prepare a test piece. Test pieces were similarly prepared for the adhesive composition for optics prepared from rosin esters 2 to 14. The test piece was kept warm for 3 hours in a 25 degree incubator.

(Measurement of surface adhesion)

The above test piece is set in the jig for interview test attached to the Autograph, and tested at a tensile speed of 5 mm/min using a precision universal testing machine (Autograph AGS-X manufactured by SHIMADZU CORPORATION). Force (N) was measured. In addition, the surface adhesion force (N/cm ² ) was calculated by dividing the test force by the area (cm ² ) of the adhesive surface of the composition of the test piece.

Claims (7)

As a plasticizer containing rosin ester,
The rosin ester is a reaction product of rosin and a monohydric alcohol having 1 to 9 carbon atoms, has a Gardner color number of 1 or less, a glass transition temperature of -15 degrees or less, and an esterification degree of 94% by weight or more. A plasticizer wherein the content of an abietic acid-type resin acid having a conjugated double bond without an aromatic ring and an ester thereof is less than 10% by weight.
According to claim 1,
A plasticizer having an acid value of the rosin ester of 2 mg KOH/g or less.
According to claim 1 or 2,
A plasticizer wherein the rosin is disproportionated rosin and/or hydrogenated rosin.
According to claim 1 or 2,
A plasticizer wherein the rosin ester contains an abietic acid-type resin acid having a conjugated double bond without an aromatic ring and the content of the ester is less than 5% by weight.
According to claim 4,
A plasticizer wherein the content of dehydroabietic acid ester in the rosin ester is 50% by weight or more, or the content of dehydroabietic acid ester is 50% by weight or more.
According to claim 4,
A plasticizer characterized in that the content of tetrahydroabietic acid ester in the rosin ester is 35% by weight or more.
An optical adhesive composition containing the plasticizer, curing component, tackifier and polymerization initiator according to claim 1 or 2.