JP2017052945A - Plasticizer and adhesive composition for optical use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasticizer which has long-term heat resistance and excellent initial tone and compatibility without inhibiting polymerization of a monomer of a thermosetting and/or active energy ray-curable resin and which can be suitably used for an adhesive composition for optical use.SOLUTION: The plasticizer comprises a rosin ester. The rosin ester is a reaction product of rosin and a monohydric alcohol having 1 to 9 carbon atoms and has a Gardner color scale of 1 or less, a glass transition temperature of -15°C or lower, and an esterification degree of 94 wt.% or more, in which a content of an abietic acid type resin acid having a conjugate double bond and no aromatic ring and its ester is less than 10 wt.%.SELECTED DRAWING: None

Description

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

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

However, these plasticizers have problems such as low heat resistance and causing early deterioration of color and resin over time. In addition, since phthalic acid plasticizers may have harmful effects on human health and the environment, an alternative to phthalic acid plasticizers is strongly desired.

On the other hand, in recent years, resins that are cured using active energy rays such as ultraviolet rays have been used from the viewpoint of environmental and human consideration and energy saving because they can be produced at room temperature with high-speed curability and without solvent. In particular, it is widely used in the fields of inks, paints, coatings, adhesions and seals, and in the field of electronic materials because it can form patterns. In the case where active energy such as ultraviolet rays cannot be irradiated, a thermosetting resin may be used.

In order to give flexibility to the cured product of such thermosetting and active energy ray curable resins, when using a conventional plasticizer, shrinkage (dimension maintenance) and yellowing associated with curing of the monomer are problems. It was. For this, for example, a compound containing an oxyalkylene group has been proposed as a plasticizer (see Patent Document 1).

However, a plasticizer with excellent heat resistance, color tone, especially color tone over time, which is regarded as important in the fields of paints, adhesives, electronic materials, etc., while suppressing the inhibition of monomer polymerization and increasing the molecular weight of the resin And an optical adhesive composition has not been developed yet.

JP 2012-1111843 A

The present invention relates to 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 tone and compatibility in good balance, and uses the same. It is an object of the present invention to provide an optical adhesive composition for optical use.

  As a result of intensive studies to develop the above-described plasticizer and optical adhesive composition as described above, the present inventors have found that the above-mentioned problems can be solved by using a specific rosin ester. The present invention has been completed based on such findings.

  That is, the present invention relates to the plasticizer and optical adhesive composition shown in the following items 1 to 7.

Item 1. A plasticizer containing a rosin ester,
The rosin ester is a reaction product of a 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 ° C. or less, and an esterification degree of 94 wt. % Of a plasticizer having an abietic acid type resin acid having a conjugated double bond having no aromatic ring and its ester content of less than 10% by weight.

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

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

  Item 4. Item 4. The plasticizer according to any one of Items 1 to 3, wherein the rosin ester has an abietic acid type resin acid having a conjugated double bond having no aromatic ring and the ester content is less than 5% by weight.

  Item 5. Item 5. The plasticizer according to Item 4, wherein the content of dihydroabietic 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.

  Item 6. Item 5. The plasticizer according to Item 4, wherein the content of tetrahydroabietic acid ester in the rosin ester is 35% by weight or more.

  Item 7. The optical adhesive composition containing the plasticizer in any one of said items 1-6, a hardening component, a tackifier, and a polymerization initiator.

  The plasticizer of the present invention does not inhibit the monomer polymerization of the active energy ray-curable and thermosetting resins, and is excellent in long-term heat resistance. It also has excellent initial color tone and compatibility. Therefore, the plasticizer of this invention can be used conveniently for the thermal and active energy ray hardening-type adhesive composition for optics.

The present invention is a plasticizer containing a rosin ester,
The rosin ester is a reaction product of a 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 ° C. or less, and an esterification degree of 94 wt. % Of a plasticizer having an abietic acid type resin acid having a conjugated double bond having no aromatic ring and its ester content of less than 10% by weight.

  Various known rosins can be used without particular limitation as rosins that are constituents of the rosin ester. Examples of rosins include gum rosin including Nesia rosin, natural rosin such as tall oil rosin and wood rosin, purified rosin obtained by purifying natural rosin, hydrogenated rosin obtained by hydrogenating natural rosin, and natural rosin. Examples thereof include disproportionated rosin obtained by a leveling reaction. As rosins, disproportionated rosin and hydrogenated rosin are more preferable. By using these, it becomes easy to obtain the obtained adhesive composition having a Gardner color number of 1 or less, and the heat resistance of the plasticizer and the optical adhesive composition can be further improved. .

  The purified rosin can be obtained using various known means such as a distillation method, an extraction method, and a recrystallization method. In the distillation method, for example, the natural rosin can be distilled under a temperature of about 200 to 300 ° C. and a reduced pressure of about 0.01 to 3 kPa. In the extraction method, for example, purified rosin can be obtained by using the above natural rosin as an alkaline aqueous solution, extracting an insoluble unsaponified product with various organic solvents, and then neutralizing the aqueous layer. In the recrystallization method, for example, the above-mentioned natural rosin is dissolved in an organic solvent as a good solvent, then the solvent is distilled off to obtain a concentrated solution, and further, an organic solvent as a poor solvent is added to obtain a purified rosin. it can.

  The disproportionated rosin can be obtained using various known means. For example, a disproportionated rosin can be obtained by subjecting a raw natural rosin or a purified purified rosin to a heat reaction in the presence of a disproportionation catalyst. As the disproportionation catalyst, palladium-carbon, rhodium-carbon, platinum-carbon and other supported catalysts; nickel, platinum and other metal powders; Can do. 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 ° C, preferably about 150 to 290 ° C. 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 rosins using known hydrogenation conditions. Specifically, for example, hydrogenation is performed by heating rosins to about 100 to 300 ° C. in the presence of a hydrogenation catalyst in a hydrogen atmosphere at about 2 to 20 MPa. The reaction pressure is preferably about 5 to 20 MPa. The reaction temperature is preferably about 150 to 300 ° C. As the hydrogenation catalyst, various known catalysts such as a supported catalyst, metal powder, iodine, and iodide can be used. Examples of the supported catalyst include palladium-carbon, rhodium-carbon, ruthenium-carbon, platinum-carbon, and the like. Examples of the metal powder include nickel and platinum. Examples of the iodide include iron iodide. Among these, palladium, rhodium, ruthenium, and platinum-based catalysts are preferable because the hydrogenation rate of rosins is increased and the hydrogenation time is shortened. In addition, the usage-amount of a hydrogenation catalyst is about 0.01-5 weight part normally with respect to 100 weight part of rosins, Preferably it is about 0.01-2 weight part.

  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 9 or more carbon atoms is used, the heat resistance of the obtained rosin ester tends to be lowered. When an alcohol other than monovalent alcohol is used, there is a problem that the viscosity of the obtained rosin ester is increased, fluidity is lowered, and plasticity is not sufficiently maintained. Among the monohydric alcohols having 1 to 9 carbon atoms, when the monohydric alcohol having 1 to 8 carbon atoms is used as a plasticizer and an optical adhesive composition, it can be preferably used in terms of excellent adhesive strength. . Specific examples of the monohydric alcohol having 1 to 8 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butyl alcohol, n-octyl alcohol, 2-ethylhexyl alcohol and the like. It is done. These can be used individually by 1 type or in combination of 2 or more types. More preferred is a monohydric alcohol having 1 to 4 carbon atoms, and most preferred is a monohydric alcohol having 1 carbon atom, that is, methanol.

  The rosin ester has a Gardner color number of 1 or less, 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 thermal / optical active energy ray-curable adhesive composition is excellent, but also the long-term heat resistance is excellent. The number of Gardner colors and the number of Hazen colors are measured in units of Gardner and Hazen, respectively, according to JIS K0071.

  The rosin ester has a glass transition temperature (Tg) of −15 ° C. or lower. When the glass transition temperature of the rosin ester is −15 ° C. or lower, a decrease in low-temperature adhesive force can be prevented without increasing the Tg of the optical adhesive composition. The glass transition temperature is preferably −15 ° C. to −35 ° C. The glass transition temperature is measured by the method specified in JIS K7121.

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 at the time of gel permeation chromatography (GPC) measurement of the rosin ester and the peak area corresponding to the monoester body in the ester. The greater the degree of esterification, the better the initial color tone and the color tone change due to heating. Specifically, it is calculated by the following equation (1). When the degree of esterification of the rosin ester is 94% by weight or more, the plasticizer is excellent in initial color tone and long-term heat resistance.
Degree of esterification of rosin ester (%) = [A / total peak area] × 100 (1)
In Formula (1), A shows the peak area (peak area corresponding to the monoester body in rosin ester) of the weight average molecular weight (polystyrene conversion value) 240.

The rosin ester contains less than 10% by weight of an abietic acid type resin acid having a conjugated double bond having no aromatic ring and its ester. 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 high molecular weight thermosetting and active energy ray curable resins. Preferably, it is less than 5% by weight, more preferably less than 0% by weight (to an extent that it cannot be detected). The content was measured by gas chromatographic analysis (GC). The rosin ester is subjected to the following pretreatment, a solution is prepared, and GC measurement is performed under the following conditions.

(Sample pretreatment method)
10 mg of rosin ester is thoroughly evaluated, and 2 mL of MeOH / toluene (50/50) mixed solution is added and dissolved. A 10% hexane solution of trimethylsilyldiazomethane is added dropwise, the sample is converted to methyl ester, and the analysis is performed.

(GC measurement conditions)
Model: Agilent 6890 Series
Column: BDS (manufactured by Supelco) 0.3 mmΦ × 25 m, film thickness 0.25 μm
Detector: Hydrogen flame ionization detector (FID)
Column temperature: 190 ° C constant 30 minutes Inlet temperature: 250 ° C
Detector temperature: 280 ° C
Carrier gas: N2 100 kPa, 2.2 mL / min
Split ratio: 50/1
Injection volume: 1.0 μL

  The abietic acid type resin acid having a conjugated double bond having no aromatic ring includes abietic acid and isomers thereof. Examples of isomers of abietic acid include neoabietic acid, levopimaric acid, and parastrinic acid, but do not include dehydroabietic acid having an aromatic ring. Also, it does not contain pimaric acid type resin acids such as pimaric acid, isopimaric acid and sandaracopimalic acid.

  It does not specifically limit as a manufacturing method of the said rosin ester, A well-known esterification method is employable. The amount of each rosin and alcohol charged is not particularly limited. Usually, the OH group of alcohol / COOH group (equivalent ratio) of rosins is about 0.8 to 8, preferably about 3 to 7. To be determined. The reaction temperature of the esterification reaction is usually about 150 to 320 ° C, preferably about 150 to 300 ° C. The reaction time is usually about 2 to 24 hours, preferably about 2 to 7 hours. Furthermore, for the purpose of shortening the reaction time, the esterification reaction can 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. Since water is produced as a result of the esterification reaction, the reaction can proceed while removing the produced water out of the system. In consideration of the color tone of the rosin ester obtained, it is desirable to carry out the reaction under an inert gas stream. The reaction can be performed under pressure if necessary. It is also possible to proceed the reaction in an organic solvent that is non-reactive with rosins and alcohols. Examples of the organic solvent include hexane, cyclohexane, toluene, xylene and the like. In addition, when an organic solvent is used, if it is necessary to distill off the solvent or an unreacted raw material, it can carry out under reduced pressure suitably.

  When purified rosin, disproportionated rosin or hydrogenated rosin is used as rosins, purification, disproportionation or hydrogenation of natural rosin is carried out after esterification of natural rosin and alcohols, or natural rosin. The rosin can be purified, disproportionated or hydrogenated and the resulting rosins and alcohols can be esterified.

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

  In the rosin ester used in the present invention, the dihydroabietic acid ester content is preferably 50% by weight or more, or the dehydroabietic acid ester content is preferably 50% by weight or more. As a result, polymerization inhibition of the heat / active energy ray-curable component can be further suppressed, and a high-molecular weight heat / active energy ray-curable resin having plasticity can be formed.

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

  The plasticizer and optical adhesive composition of the present invention can be obtained using the rosin ester. Since the plasticizer and the optical adhesive composition of the present invention are excellent in heat resistance, they can be suitably used in applications where heat resistance is important. For example, hot-melt adhesives used in packaging, bookbinding, disposable diapers or sanitary products where color tone at high temperatures is important; optical plasticizers added to optical resins where transparency is important And optical adhesives such as OCA (Optically Clear Adhesive) and OCR (Optically Clear Resin); adhesives for films and the like. The content of the rosin ester is preferably about 1 to 100 parts by weight when the composition is 100 parts by weight. By making the content of the rosin ester within this range, the effect of improving the plasticity and the adhesive performance by adding the rosin ester is exhibited. A more preferable content is about 1 to 40 parts by weight.

The plasticizer of the present invention may contain other additives other than the rosin ester as long as the effects of the present invention are not impaired. Examples of other additives include an antioxidant, a polymerization inhibitor, and a sensitizer. The other additive is preferably 0.5 to 10 parts by weight when the plasticizer is 100 parts by weight.

The adhesive composition for optics containing the plasticizer of this invention, a hardening component, tackifying resin, and a polymerization initiator is also one of this invention. The curing component includes a thermosetting component and an active energy ray curing component.

As the thermosetting component, thermosetting resins such as epoxy resin, phenol resin, unsaturated polyester resin, urea resin, melamine resin, diallyl phthalate resin, silicon resin, vinyl ester resin, polyimide resin, polyurethane resin, etc. are obtained by thermosetting. It will not specifically limit if it can form, It can use combining 1 type (s) or 2 or more types. Specific examples include “COMPOSELLA”, “ARACOAT”, and “ARAQUID” manufactured by Arakawa Chemical Industries, Ltd.

As said active energy ray hardening component, the compound hardened | cured by active energy rays (electron beam, ultraviolet rays, etc.), such as a monomer, an oligomer, and a polymer, is mentioned.

Specific examples of the monomer and oligomer include butyl acrylate, butadiene acrylate, urethane acrylate, silicon acrylate, epoxy acrylate, and the like. A monomer is also called a monomer, and is a raw material in the case of synthesizing a polymer by a curing reaction. The oligomer is also called a low polymer, and is a raw material in the case of synthesizing a polymer by a curing reaction, although the degree of polymerization is in a relatively low state of about 2 to 20.

As the polymer, various known polymers can be used without particular limitation as long as they are radically polymerized by active energy rays such as ultraviolet rays and electron beams to form a cured film. Specific examples include polyacryl acrylate, polyurethane acrylate, polyester acrylate and the like (for example, “Beam Set Series” manufactured by Arakawa Chemical Industries, Ltd.).

The tackifier is not particularly limited as long as it is generally used as a tackifier resin. For example, petroleum resin, phenol resin, xylene resin, coumarone resin, rosin resin, terpene resin, hydrogenated petroleum resin. Hydrogenated rosin resins, hydrogenated terpene resins, and the like can be used. Among them, a color tone having a Gardner color number of 1 or less is preferable. Examples of the color tone having a Gardner color number of 1 or less include hydrogenated petroleum resins and hydrogenated rosin resins. These hydrogenated resins are usually tackifiers having excellent transparency because the color tone is 1 or less Gardner color, and improve the transparency of the optical pressure-sensitive adhesive and the pressure-sensitive adhesive layer. Furthermore, since these hydrogenated resins have little polymerization inhibition during polymerization by irradiation with active energy rays such as thermosetting and ultraviolet rays, by using these, an optical adhesive having excellent curability and Become. These can be used alone or in combination of two or more. Specifically, for example, a hydrogenated rosin resin of Pine Crystal Series (Pine Crystal KE-311, Pine Crystal KE-100, etc.) manufactured by Arakawa Chemical Industries, Ltd. may be mentioned. Among these, it is particularly preferable to use KE-311 having a good color tone and low polymerization inhibition. More preferably, it is a completely hydrogenated rosin resin. Completely hydrogenated rosin ester is very suitable as an optical tackifier because it has a completely colorless initial color tone, excellent temporal stability, and good heat stability. Therefore, a fully hydrogenated rosin ester as a tackifier and an adhesive composition using the plasticizer of the present invention can suppress polymerization inhibition of the base resin contained in the adhesive composition. In addition, the adhesive can be imparted with plasticity and can be made into an adhesive having excellent color tone and stability over time, and is therefore suitable as an optical adhesive composition.

The polymerization initiator is not particularly limited as long as it can start polymerization by generating radicals with heat and active energy rays, and a known one can be used. Examples of the photopolymerization initiator include compounds that generate radicals by hydrogen abstraction such as benzophenone, benzyl, Michler ketone, thioxanthone, and anthraquinone, benzoin, dialkoxyacetophenone, acyloxime ester, benzyl ketal, hydroxyalkylphenone, halogeno A compound of a type that generates radicals by intramolecular cleavage, such as a ketone, can be appropriately selected and employed. Examples of the polymerization inhibitor include hydroquinone, benzoquinone, toluhydroquinone, para tertiary butyl catechol, and the like. Examples of photosensitizers include amines such as aliphatic amines and aromatic amines, ureas such as o-tolylthiourea, sodium diethyldithiophosphate, and s-benzylisothiuronium-p-toluenesulfonate. And sulfur compounds. These can be used alone or in combination of two or more. In particular, 2-hydroxy-2-methyl-1-phenyl-propan-1-one is preferred in terms of non-yellowing, handling properties and compatibility.

In the optical pressure-sensitive adhesive composition of the present invention, the plasticizer, the curing component and the tackifier resin are mixed at a temperature of 10 to 70 ° C. under atmospheric pressure at the following ratio, and then the polymerization initiator is mixed. It can manufacture by adding.

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

  Examples of the adhesive composition include an acrylic adhesive composition, a styrene-conjugated diene block copolymer adhesive composition, and an ethylene hot melt adhesive composition. Is mentioned. Among these, an acrylic adhesive composition is preferable in that it has excellent heat resistance and can control the adhesive force in a wide range.

  The acrylic adhesive composition of the present invention contains the rosin ester and an acrylic polymer. The acrylic adhesive composition can be obtained, for example, by blending a rosin ester with an acrylic polymer that is a base polymer. The content of the acrylic polymer is preferably about 1 to 50 parts by weight when the composition is 100 parts by weight. By making content of an acrylic polymer into this range, the plastic performance improvement effect by adding rosin ester expresses. A more preferable content is about 1 to 40 parts by weight.

  There is no restriction | limiting in particular in the said acrylic polymer, The various well-known homopolymer or copolymer currently used as an acrylic adhesive composition can be used as it is. As a monomer used for the acrylic polymer, various (meth) acrylic acid esters (in addition, “(meth) acrylic acid ester” means an acrylic acid ester and / or a methacrylic acid ester. (Meth) acrylic acid "has the same meaning). Specific examples of the (meth) acrylic acid ester include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and the like. These can be used alone or in combination of two or more. In order to impart polarity to the resulting acrylic polymer, a small amount of (meth) acrylic acid can be used instead of a part of the (meth) acrylic acid ester. Further, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N-methylol (meth) acrylamide and the like can be used in combination as the crosslinkable monomer. Furthermore, if desired, other copolymerizable monomers such as vinyl acetate and styrene can be used in combination as long as the adhesive properties of the (meth) acrylic acid ester polymer are not impaired. Various known methods can be used as the polymerization method. Besides using a general radical polymerization method, a cationic polymerization method, a living radical polymerization method, a living anion polymerization method, or the like can be used.

  The glass transition temperature of the acrylic polymer containing the (meth) acrylic acid ester as a main component is not particularly limited, and is usually about −90 to 0 ° C., preferably in the range of −80 to −10 ° C. . If the glass transition temperature is too high than 0 ° C., the tack tends to decrease, and if it is too low, the adhesive strength tends to decrease. 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, and preferably about 100,000 to 1,000,000. By setting the molecular weight within this range, the adhesive strength is improved. The weight average molecular weight is a standard polystyrene conversion value measured by gel permeation chromatography (GPC).

  In addition, what is necessary is just to employ | adopt various well-known methods for the manufacturing method of the said acrylic polymer. As a method for producing the acrylic polymer, for example, a radical polymerization method such as a bulk polymerization method, a solution polymerization method, or a suspension polymerization method can be appropriately selected. As the radical polymerization initiator, various known azo and peroxide initiators can be used. The reaction temperature is usually about 50 to 85 ° C. The reaction time is about 1 to 8 hours. Further, as the solvent for the acrylic polymer, a solvent such as ethyl acetate or toluene is generally used, and the solution concentration is preferably about 40 to 60% by weight.

  In addition, the acrylic adhesive composition of this invention can add crosslinking agents, such as a polyisocyanate, a polyamine, a melamine resin, a urea resin, an epoxy resin, to the said acrylic polymer and tackifying resin. By adding a cross-linking agent, the cohesive force and heat resistance can be further improved. Among these crosslinking agents, it is particularly preferable to use polyisocyanate. A conventionally well-known thing can be widely used as polyisocyanate. Specific examples thereof include 1,6-hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, and the like. Furthermore, in the acrylic adhesive composition of the present invention, additives such as a filler, an antioxidant, and an ultraviolet absorber can be appropriately used as necessary. The acrylic adhesive composition of the present invention can be used in combination with various known tackifying resins other than the rosin ester without departing from the object of the present invention.

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

  The styrene-conjugated diene block copolymer is a block copolymer obtained by copolymerizing styrenes such as styrene and methylstyrene and conjugated dienes such as butadiene and isoprene as appropriate according to the purpose of use. It is. Usually, the weight ratio of styrenes / conjugated diene is 10/90 to 50/50. Preferable specific examples of such a block copolymer include, for example, an SBS type block copolymer and a styrene having a weight ratio of styrenes (S) / budadiene (B) in the range of 10/90 to 50/50. Examples thereof include SIS type block copolymers having a weight ratio of (S) / isoprene (I) in the range of 10/90 to 30/70. The styrene-conjugated diene block copolymer includes those obtained by hydrogenating the conjugated diene component of the block copolymer. Specific examples of the hydrogenated material include so-called SEBS type block copolymers and SEPS type block copolymers.

  If necessary, additives such as oil, tackifier, filler, and antioxidant can be added to the styrene-conjugated diene block copolymer pressure-sensitive adhesive composition.

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

  The said ethylene-type copolymer is a copolymer of ethylene and a monomer copolymerizable with ethylene, and what was conventionally used for the hot-melt-adhesive can be used. Examples of the monomer copolymerizable with ethylene include vinyl acetate. The content of vinyl acetate is usually about 20 to 45% by weight. In addition, it is preferable that the melt index (190 degreeC, load 2160g, 10 minutes) of an ethylene-type copolymer is about 10-400 g / 10min.

  In addition, additives, such as a wax, a tackifier, a filler, and an antioxidant, can be further added to the ethylene-based hot melt adhesive composition as necessary.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and the method of this invention is demonstrated in more detail, this invention is not limited to these. In the examples, “%” represents “% by weight”, and “parts” represents “parts by weight”.

Production Example 1 (Production of rosin ester 1)
100 g of Chinese disproportionated rosin (manufactured by Guangxi Zhengzhou Arakawa Chemical Co., Ltd.) and 300 g of methanol were charged into a 1 L autoclave to remove oxygen in the system, and then the temperature was raised to 290 ° C. The internal pressure of the autoclave reached up to 14 MPa. The esterification reaction was carried out for 2 hours while depressurizing every 20 minutes and removing water vapor. After concentrating the obtained reaction liquid with a rotary evaporator, 5 g of calcium hydroxide was added, and 68 g of rosin ester 1 was obtained as a main fraction by simple distillation under conditions of a liquid temperature of 150 to 270 ° C. and a pressure of 0.4 kPa. .

Production Example 2 (Production of rosin ester 2)
65 g of rosin ester 2 was obtained in the same manner as in Production Example 1, except that the Chinese disproportionated rosin was changed to a Chinese hydrogenated rosin (manufactured by Guangxi Yinzhou Nislin Forestry Chemical Co., Ltd.).

Production Example 3 (Production of rosin ester 3)
66 g of rosin ester 3 was obtained in the same manner as in Production Example 1, except that Chinese disproportionated rosin was changed to distilled disproportionated rosin (manufactured by Arakawa Chemical Industries, Ltd.).

Production Example 4 (Production of rosin ester 4)
The rosin ester 3, 100 g 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 introducing tube, heated to 40 ° C. and dissolved, and then the container was used as a constant temperature circulation device. Soaked. The temperature was lowered from 40 ° C., and seed crystals were added on the way. After the flocculent white crystals increased rapidly, the temperature of the apparatus was lowered to 5 ° C. and held for 1.5 hours. Thereafter, in suction filtration, the crystals were washed with 2-propanol which was 1/3 to 1/2 times the amount of raw material charged, and then dried under reduced pressure at 50 ° C. and 10 Torr for 2 hours to obtain 49 g of rosin ester 4.

Production Example 5 (Production of rosin ester 5)
The rosin ester 3, 100 g 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 introduction tube, heated to 40 ° C. and dissolved, and then the container was used as a constant temperature circulation device. Soaked. The temperature was lowered from 40 ° C., and seed crystals were added on the way. After the flocculent white crystals increased rapidly, the temperature of the apparatus was lowered to 5 ° C. and held for 1.5 hours. Thereafter, in suction filtration, the crystal is washed with 2-propanol which is 1/3 to 1/2 times the amount of raw material, and then dried under reduced pressure at 50 ° C. and 10 Torr for 2 hours. The above-mentioned recrystallization operation was further repeated twice for the obtained crystals to obtain 28 g of rosin ester 5.

Production Example 6 (Production of rosin ester 6)
64 g of rosin ester 6 was obtained in the same manner as in Production Example 1, except that the Chinese disproportionated rosin was changed to highly hydrogenated rosin (Forester Chemical Co., Ltd.).

Production Example 7 (Production of rosin ester 7)
Distilled hydrogenated rosin (Arakawa Chemical Industries, Ltd., dihydroabietic acid: 68.9%, tetrahydroabietic acid: 20.6%) and 500 g of palladium / carbon catalyst 5C-50W (manufactured by N.E. Chemcat Co., Ltd.) 15 g of 50% product (containing water) was charged into a 1 L flask, sealed with N 2, heated to 190 ° C. and dehydrated for 1 hour. Next, the melt was transferred to a 2 L autoclave, diluted with 500 g of methylcyclohexane, and then subjected to a hydrogenation reaction under conditions of 7 to 10 Mpa and 150 to 300 ° C. for 3 hours. After removing the catalyst by filtration, the reaction solution was transferred to a 1 L flask, heated to 200 ° C. to remove methylcyclohexane, and further distilled under reduced pressure at 15 mmHg for 30 minutes. Thereafter, 1500 g of the reaction solution and 1500 g of methanol were charged into a 5 L autoclave, and after removing oxygen in the system, the temperature was raised to 290 ° C., and the esterification reaction was carried out for 2 hours while depressurizing every 20 minutes and removing water vapor. At that time, the internal pressure of the autoclave reached up to 14 MPa. After concentrating the obtained reaction liquid with 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 ° C. and a pressure of 0.4 kPa.

Production Example 8 (Production of rosin ester 8)
Rosin ester 2, 48 g and rosin ester 11, 3 g described later were added to a 200 mL beaker and stirred at 70 ° C. for 30 minutes in a water bath to obtain 51 g of rosin ester 8.

Production Example 9 (Production of rosin ester 9)
Rosin ester 2, 45 g and rosin ester 11, 6 g described later were added to a 200 mL beaker and stirred at 70 ° C. for 30 minutes in a water bath to obtain 51 g of rosin ester 9.

Production Example 10 (Production 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 Production Example 1 (Production of rosin ester 11)
65 g of rosin ester 11 was obtained in the same manner as in Production Example 1, except that the Chinese disproportionated rosin in Production Example 1 was changed to Chinese gum rosin (Guangxi Yinzhou Arakawa Chemical Co., Ltd.).

Comparative Production Example 2 (Production 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 Production Example 3 (Production of rosin ester 13)
50 g of rosin ester 13 was obtained by adding rosin ester 2,37 g and rosin ester 11,13 g to a 200 mL beaker and stirring in a water bath at 70 ° C. for 30 minutes.

  As rosin ester 14, Hercolin D (hydrogenated rosin methyl ester, manufactured by Eastman Chemical Co.) was used.

Various 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 DSC) defined in JIS K7121.
DSC measuring device: DSC8230B manufactured by Rigaku Denki Co., Ltd.
Color tone: Measured in units of Gardner and Hazen according to JIS K0071.
Acid value: Measured according to JIS K0070.

<Calculation of degree of esterification>
Rosin esters 1-14 were dissolved in tetrahydrofuran to prepare a 0.5% solution. This solution was subjected to GPC measurement under the following conditions, and the degree of esterification was calculated from the following formula (1).

(GPC measurement conditions)
Model: Product name “HLC-8220”, manufactured by Tosoh Corporation Column: Product name “TSKgel G2500HXL”, manufactured by Tosoh Corporation, one
Product name "TSKgel G2000HXL", manufactured by Tosoh Corporation
Product name “TSKgel G1000HXL”, manufactured by Tosoh Corporation, one connected development solvent flow rate: tetrahydrofuran, 1 mL / min Measurement temperature: 40 ° C.
Detector: RI

Degree of esterification (%) of rosin esters 1 to 14 = [A / total total peak area] × 100 (1)
In formula (1), A shows the peak area (peak area corresponding to the monoester body in rosin ester 1-14) of the weight average molecular weight (polystyrene conversion value) 240.

<Analysis of rosin ester composition ratio>
The analysis of the composition ratio of the rosin component (resin acid component) in the rosin ester in the present invention was analyzed by gas chromatographic analysis (GC). The rosin ester was subjected to the following pretreatment, a solution was prepared, and GC measurement was performed under the following conditions. The results are shown in Table 2.

(Sample pretreatment method)
10 mg of rosin ester is thoroughly evaluated, and 2 mL of methanol / toluene (50/50) mixed solution is added and dissolved. A 10% hexane solution of trimethylsilyldiazomethane was added dropwise, and the sample was converted to methyl ester for analysis.

(GC measurement conditions)
Model: Agilent 6890 Series
Column: BDS (manufactured by Supelco) 0.3 mmΦ × 25 m, film thickness 0.25 μm
Detector: Hydrogen flame ionization detector (FID)
Column temperature: 190 ° C constant 30 minutes Inlet temperature: 250 ° C
Detector temperature: 280 ° C
Carrier gas: N2 100 kPa, 2.2 mL / min
Split ratio: 50/1
Injection volume: 1.0 μL

The composition ratio of the rosin ester was calculated by dividing every retention time (hereinafter also referred to as RT).
Neutral component: peak detected at RT 0 to 4.1 minutes Tetrahydroabietic acid ester: RT peak detected at 4.1 minutes to 10 minutes, 4.6 minutes, 5.1 minutes, 5.3 minutes Peak dihydroabietic acid ester detected at 5.6 minutes, 5.8 minutes, 6.0 minutes, 6.1 minutes, 6.4 minutes, 7.0 minutes: detected at RT 4.1 minutes to 10 minutes Among those peaks, 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 1-10, Comparative Examples 1-5
Using rosin esters 1 to 14 as plasticizers, polymerization inhibition, heat resistance and adhesive strength were evaluated. Moreover, the conditions which do not use a plasticizer were described in Comparative Example 1. The results are shown in Table 4.

<Evaluation of polymerization inhibition rate>
Samples for evaluation of polymerization inhibition were prepared as follows. 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) are added and dissolved. A sample for evaluation was used. In addition, similar evaluation samples were prepared by changing the plasticizer as shown in Table 3.

  The polymerization inhibitory property of the plasticizer in the present invention was evaluated by calculating the polymerization rate and polymerization average molecular weight by GPC. Details are described below.

  The obtained sample was put in a UV irradiation box (manufactured by JATEC Corporation), and irradiated with a high-pressure mercury lamp from a UV irradiation apparatus (manufactured by Toshiba Lighting & Technology Corporation, TOSCURE 401) for 30 seconds. GPC was measured by sampling after irradiation for 10 and 30 seconds.

(GPC measurement conditions)
Model: Product name “HLC-8220”, column manufactured by Tosoh Corporation: Product name “TSKgel SuperHM-L” × 3 Development solvent flow rate: Tetrahydrofuran, 0.6 mL / min Measurement temperature: 40 ° C.
Detector: RI

(Polymerization rate)
Polymerization rate (%) = P / (P + M) (2)
P: GPC peak area ratio of acrylic polymer (peak detected at retention time of 8 to 13 minutes)
M: GPC peak area ratio of acrylic monomer (peak detected at retention time 15.5 minutes to 16.5 minutes)
The higher the polymerization rate, the lower the polymerization inhibition and the better.

(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, the lower the polymerization inhibition and the better.
Table 4 shows the results of the polymerization rate and the weight average molecular weight.

<Heat resistance>
5 g of rosin ester 1 is taken in a glass test tube (outer diameter: 15 mm, length: 150 mm, wall thickness: 10 mm), and the test tube is set up vertically in a test tube stand in a circulating air dryer at 95 ° C. Left for 10 days. The color tone before heating and after heating for 10 days was evaluated in units of Gardner. In addition, when less than 1 Gardner, it was evaluated by Hazen color tone. Further, rosin esters 2 to 14 were similarly evaluated.

<Surface adhesive strength>
(Preparation of optical adhesive composition)
Urethane acrylate (trade name “UA-160TM”, Shin-Nakamura Chemical Co., Ltd.) 26.5 parts, monomer as dodecyl acrylate (LA, manufactured by Wako Pure Chemical Industries, Ltd.) 19.9 parts and isobornyl acrylate (IBXA, manufactured by Tokyo Chemical Industry Co., Ltd.) 12.4 parts, plasticizer (rosin ester 1) 40.0 parts, Irgacure TPO (manufactured by BASF) as photoinitiator 0.3 parts and Irgacure 184 (manufactured by BASF) ) 0.9 part was added and dissolved. Moreover, the sample for evaluation was similarly prepared about rosin ester 2-14.

(Creation of specimen)
Prepare two glass plates (76 mm × 26 mm × 1.2-1.5 mm, Matsunami Glass Industry Co., Ltd.), place a 150 μm PET film as a spacer on one glass plate, and place it in the center of the other glass plate. A small amount of the optical adhesive composition prepared from rosin ester 1 was dropped, and two glass plates were bonded together in a cross shape. The amount of the sample was adjusted so that the adhesive surface to which the adhesive composition was bonded was about 10 mm in diameter in order to prevent the adhesive surface from sticking out or sticking to the spacer. Then, using a high pressure mercury lamp, the integrated quantity of light at an intensity 150 mJ / cm ² is a test piece was prepared by irradiating ultraviolet rays so that the 3,000 mJ / cm ^2. Test pieces were similarly prepared for the optical adhesive composition prepared from rosin esters 2-14. The specimen was kept warm in an incubator at 25 ° C. for 3 hours.

(Measurement of surface adhesion)
The test piece is set in a jig for surface adhesion test attached to the autograph, and using a precision universal testing machine (Autograph AGS-X, manufactured by Shimadzu Corporation), the test force is 5 mm / min. (N) was measured. The surface adhesive force (N / cm ² ) was calculated by dividing the test force by the area (cm ² ) of the composition adhesive surface of the test piece. Note that the optical adhesive composition of Comparative Example 2 could not be measured because it was not sufficiently cured when irradiated with ultraviolet rays.

Claims (7)

A plasticizer containing a rosin ester,
The rosin ester is a reaction product of a 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 ° C. or less, and an esterification degree of 94 wt. % Of a plasticizer having an abietic acid type resin acid having a conjugated double bond having no aromatic ring and its ester content of less than 10% by weight.   The plasticizer according to claim 1, wherein the acid value of the rosin ester is 2 mgKOH / g or less.   The plasticizer according to claim 1 or 2, wherein the rosin is a disproportionated rosin and / or a hydrogenated rosin.   The plasticizer according to any one of claims 1 to 3, wherein the rosin ester contains less than 5% by weight of an abietic acid type resin acid having a conjugated double bond having no aromatic ring and an ester thereof.   The plasticizer according to claim 4, wherein the content of the dihydroabietic acid ester in the rosin ester is 50% by weight or more or the content of the dehydroabietic acid ester is 50% by weight or more.   The plasticizer according to claim 4, wherein the content of tetrahydroabietic acid ester in the rosin ester is 35% by weight or more. The optical adhesive composition containing the plasticizer in any one of Claims 1-6, a hardening component, a tackifier, and a polymerization initiator.