JP4113174B2 - Method for producing acrylic terpene graft copolymer - Google Patents

Description

  The present invention relates to an acrylic terpene graft copolymer and a method for producing an aqueous coating composition having the function of an adhesive containing the acrylic terpene graft copolymer.

  More specifically, in the continuous bulk polymerization process using a chain transfer agent, the present invention provides a mixture of a phenol-modified terpene resin and an acrylic monomer as main components under a specific condition, thereby allowing an acrylic resin to be polymerized. The present invention relates to a method for producing a terpene graft copolymer and a method for producing an aqueous coating composition having an adhesive function for further neutralizing and water-solubilizing the obtained copolymer.

  Various inks, paints, adhesives, and adhesives applied to various base materials such as metals, plastics, wood, glass, concrete, and other inorganic materials, paper, and cloth Even when applied to various substrates, it is required to have the adhesive strength required for each substrate.

  As a conventional technique that has been adopted for such demands, regardless of whether it is aqueous or organic, a base resin that is a main component constituting the coating film and a tackifying resin that imparts tackiness Binary blended coating compositions that are miscible are common. This binary blend coating composition is prepared by mixing a base resin and a tackifier resin in an organic solvent if it is an organic solvent, and preparing respective emulsions if they are aqueous and mixing them together. Is common.

  The tackifying resin is usually an amorphous oligomer having a molecular weight of several hundred to several thousand, and natural resins such as rosin, terpene and coumarone, or synthetic petroleum resins such as cyclopentadiene are used as the tackifying resin.

  Incidentally, it is important to enhance the compatibility between the base resin and the tackifying resin so that the coating composition having the adhesive function can exhibit a strong adhesive force regardless of the type of the substrate. That is, when the compatibility of both is high, depending on the concentration of the tackifying resin, the peel strength of the coating film, particularly the peel strength at high temperatures, can be enhanced. On the other hand, when the compatibility between the two is low, the peel strength of the coating film cannot be increased by the concentration of the tackifying resin.

  In this regard, in the coating composition having an organic solvent-based adhesive function, in order to increase the compatibility between the base resin and the tackifying resin, the composition and blend ratio of the base resin and the tackifying resin are increased. In addition, the temperature at which both coexist is optimized.

  On the other hand, in recent years, conversion to an aqueous coating composition that does not use an organic solvent has progressed due to a demand for environmental measures, and attempts to increase the adhesive function of the aqueous coating composition have been actively conducted. .

  However, in an aqueous coating composition having an adhesive function in which a base resin and a tackifying resin are dispersed in an aqueous medium, basically, the base resin and the tackifying resin are in an incompatible state. Since it is dispersed in the medium, the coating composition has firstly the problem of how to make the thixotropic flow characteristic close to the Newtonian flow characteristic, and secondly, the uniform film-forming property ( There is a problem of how to ensure that the base resin particles and the tackifying resin particles in the emulsion are fused and the film thickness is uniform at the micro level.

Conventionally, various methods such as the following 1) to 7) have been disclosed for this problem.
1) A method in which a tackifying resin is emulsified in water and added to a mixture of an aqueous dispersion of a styrene / acrylic copolymer and an aqueous solution of an alkali-soluble acrylic copolymer (Patent Documents 1 and 2).
2) A method of adding an aqueous dispersion of a tackifying resin to an acrylic emulsion for a re-peeling pressure-sensitive adhesive sheet (Patent Document 3).
3) An emulsion of a tackifying resin containing a nonionic polymer compound having a hydrophobic chain site in the molecule and a hydrophilic chain site at both ends of the molecule as a surfactant (emulsifier) is added to the acrylic emulsion to add acrylic A method for increasing the affinity between a resin and a tackifying resin (Patent Document 4).
4) A method of blending aqueous dispersions of various tackifying resins into a mixture of an aqueous alkaline solution of styrene / acrylic copolymer and an acrylic emulsion, and by optimizing the compounding ratio of these components, aqueous printing A method for obtaining an aqueous dispersion suitable for ink (Patent Document 5).
5) A method for producing an acrylic emulsion adhesive obtained by emulsion polymerization of a monomer mixture in which a tackifying resin is previously dissolved or dispersed (Patent Document 6).
6) A method for producing an emulsion, wherein a monomer mixture containing a specific monomer is polymerized in the presence of a tackifier resin emulsion, and then a monomer mixture containing a specific alkyl (meth) acrylate is emulsion-polymerized ( Patent Document 7).

  However, the aqueous coating composition having an adhesive function obtained by these conventional methods is fundamentally a binary blend aqueous emulsion in which a base resin and a tackifying resin are dispersed in an aqueous medium. Therefore, the first and second problems caused by the essential characteristics cannot be fundamentally solved.

  On the other hand, a method for producing a reversed-phase core-shell emulsion has been proposed in which a water-soluble resin (referred to as a support resin) is used instead of an emulsifier, and an acrylic monomer is emulsion-polymerized in the presence of the resin ( Patent Documents 8, 9 and 10).

  However, even in this method, a water-soluble resin such as a tackifier resin that is normally fat-soluble and an acrylic resin that is water-soluble is incompatible and exists in a localized manner. The above-mentioned problem of the binary blend system in which the tackifying resin is dispersed in an aqueous medium cannot be completely solved.

  On the other hand, terpenes that do not contain conjugated double bonds such as α-pinene, β-pinene, and limonene (dipentene) can be obtained using olefinically unsaturated carboxylic acids or their anhydrides, other vinyl monomers, and peroxide catalysts. A method of copolymerization by bulk radical polymerization is disclosed (Patent Document 11).

  However, in this method, since the obtained copolymer is a random copolymer, the function as a base resin originally possessed by the olefinically unsaturated carboxylic acid or the like cannot be sufficiently exhibited. In addition, in the method described in this document, when an olefinically unsaturated carboxylic acid or the like and other vinyl monomer are copolymerized, a polymerizable monomer having an acidic group such as an olefinically unsaturated carboxylic acid at the initial stage of the polymerization reaction. However, in the latter stage of the polymerization reaction, a small amount or no polymerizable monomer having an acidic group such as the olefinically unsaturated carboxylic acid is introduced into the polymer. Was not considered at all.

  For this reason, the copolymer obtained by this method is a mixture of a polymer having many acidic groups, a polymer having few acidic groups, and, in an extreme case, a copolymer having no acidic groups at all. When the obtained copolymer is neutralized with alkali, the copolymer with many acidic groups occupies alkali and dissolves in water, but the copolymer with few acidic groups deprived of alkali is subjected to alkali neutralization. The effect of water solubilization was small, and it was obtained as an opaque dispersion as a whole.

  Thus, the copolymer obtained by this method is exclusively used as a “tackifier” by being dispersed and mixed with another base resin. This conventional method uses a base resin and a tackifier resin as an aqueous medium. However, it did not solve the essential problem of the aqueous coating composition of the binary blend system dispersed therein.

JP-A-10-292290 JP-A-11-247094 JP 2000-281996 A JP2003-238932A JP 5-50551 JP 58-185668 JP-A 64-79281 Japanese Patent No. 2963897 Patent No. 3012641 Japanese Patent No. 3067060 Special table hei 9-511012

  The present invention fundamentally solves the problems of conventional aqueous coating compositions having a binary adhesive function, that is, maintains both functions of the base resin and the tackifying resin constituting the coating film. Co-existing in the same molecule as it is, to achieve the ultimate compatibility of both resins, including a copolymer that can be completely dissolved in water and give uniform film-forming properties, and the like The object is to enable the production of an aqueous coating composition having an adhesive function.

As a result of intensive studies to achieve the above object, the present inventors have
Select a phenol-modified terpene resin as the tackifying segment, mix a relatively large amount of (meth) acrylic acid with the acrylic monomer and styrene into the tackifying segment, and polymerize the mixture in the presence of a chain transfer agent. While radical polymerization was carried out in multiple reaction zones that gradually increased in temperature within a specific temperature range while relaxing the polymerization rate using styrene-based thermal polymerization without using an initiator, a certain amount of terpene segment was acrylic. The present invention has been completed by finding that it can be grafted to a trunk made of a copolymer and that the acidic group imparting water solubility can be retained in a certain range in the graft copolymer.

［式中、ｍ及びｎは１以上の整数を表す］
で示される構造を有し、ＯＨ価が１５０以上２５０であり、数平均分子量５００乃至２０００である、フェノール変性テルペン樹脂の少なくとも１種と、アクリル酸及び／又はメタアクリル酸（以下、まとめて「（メタ）アクリル酸」と記す）と、（メタ）アクリル酸のエステルと、スチレンと、任意に加えられるこれらと共重合可能な不飽和モノマーとを、連鎖移動剤と共に、フェノール変性テルペン樹脂、（メタ）アクリル酸、（メタ）アクリル酸のエステル、スチレン、不飽和モノマー及び連鎖移動剤の総量に対して、フェノール変性テルペン樹脂を２０重量％未満、（メタ）アクリル酸を１５〜３５重量％含有する組成比で混合し、得られた混合物を、重合開始剤を使用せずに、以下の条件を満たす、T_１〜T₄の混合物温度を与える４つの反応ゾーンを、この順で通過させる工程を含む、

［上記式中、T_１は第１反応ゾーンの反応物温度であり、T_２は第２反応ゾーンの反応物温度であり、T₃は第３反応ゾーンの反応物温度であり、T₄は第４反応ゾーンの反応物温度である］
（メタ）アクリル酸、（メタ）アクリル酸のエステル、スチレン及び任意に加えられるこれらと共重合可能な不飽和モノマーの共重合体を幹とし、フェノール変性テルペン樹脂がこの幹にグラフトしている、重量平均分子量Ｍｗが１０００乃至１００００で、重量平均分子量の数平均分子量に対する比（ｎ）が１から５である、アクリル系テルペン樹脂グラフト共重合体の製造方法を提供するものである。 That is, in the present invention, the repeating unit is represented by the following formula (1):

[Wherein, m and n represent an integer of 1 or more]
And at least one phenol-modified terpene resin having an OH number of 150 to 250 and a number average molecular weight of 500 to 2000, acrylic acid and / or methacrylic acid (hereinafter collectively “ (Referred to as “(meth) acrylic acid”), an ester of (meth) acrylic acid, styrene, and an optionally added unsaturated monomer copolymerizable with these, together with a chain transfer agent, a phenol-modified terpene resin, Less than 20% by weight of phenol-modified terpene resin and 15 to 35% by weight of (meth) acrylic acid based on the total amount of (meth) acrylic acid, ester of (meth) acrylic acid, styrene, unsaturated monomer and chain transfer agent were mixed in a composition ratio of the resulting mixture, without using a polymerization initiator, the following condition is satisfied, gives a mixture temperature of T ₁ through T ₄ One of the reaction zone, comprising the step of passing in this order,

[Wherein T ₁ is the reactant temperature in the first reaction zone, T ₂ is the reactant temperature in the second reaction zone, T ₃ is the reactant temperature in the third reaction zone, and T ₄ is It is the reactant temperature in the fourth reaction zone]
(Meth) acrylic acid, (meth) acrylic acid ester, styrene and a copolymer of unsaturated monomers copolymerizable with these optionally added as a trunk, and a phenol-modified terpene resin is grafted on this trunk, The present invention provides a method for producing an acrylic terpene resin graft copolymer having a weight average molecular weight Mw of 1000 to 10,000 and a ratio (n) of the weight average molecular weight to the number average molecular weight of 1 to 5.

In the production method of the present invention, it is preferred that the reactants temperature of each reaction zone (T ₁ ~T _n) is a 140-270 ° C..

In the production method of the present invention, the reaction temperature of each reaction zone _{(T 1, T 2, T} 3, T 4) is preferably the following conditions are satisfied.

Also in this preferred embodiment, the reactant temperature (T ₁ ) in the first reaction zone is 140-160 ° C., the reactant temperature (T ₂ ) in the second reaction zone is 170-190 ° C., It is preferable that the reactant temperature (T ₃ ) in the third reaction zone is 200 to 250 ° C., and the reactant temperature (T ₄ ) in the fourth reaction zone is 230 to 270 ° C.

  Moreover, in the manufacturing method of this invention, it is preferable that the residence time in each reaction zone is 5 to 20 minutes.

  The present invention further includes an aqueous coating composition having an adhesive function, comprising a step of neutralizing and dissolving the obtained copolymer with alkaline water after the step of producing the copolymer of the present invention. The manufacturing method of this is provided.

  The present invention also provides an acrylic terpene graft copolymer obtained by the method of the present invention and an aqueous coating composition having an adhesive function.

  In the present specification, the term “coating composition having an adhesive function” is used for coating materials such as paints and inks, and can form a coating film, and can also be used for adhesion and adhesion to the formed coating film. It means a composition capable of imparting properties.

  According to the production method of the present invention, a phenol-modified terpene resin that is one type of tackifier resin is grafted to an acrylic copolymer that is a main component constituting a coating film, and the base resin and the tackifier resin are In other words, it is possible to obtain a graft copolymer that exists in an ultimate compatible state while maintaining the properties and retains a carboxyl group to the extent that it can be neutralized and water-solubilized with alkaline water. For this reason, in the coating composition in which the copolymer is dissolved in an aqueous solvent, each resin having the characteristics as a base resin and a tackifying resin is uniformly and completely dissolved. Without adding an imparting agent separately, it is possible to impart desired adhesive properties to the coating film to be formed, and the resin in the coating composition has a Newtonian flow property and is excellent in film forming properties. Can be formed.

  As described above, the production method of the present invention comprises at least one phenol-modified terpene resin having a predetermined chemical structure, (meth) acrylic acid, an ester of (meth) acrylic acid, styrene, and polymerization of these monomers. It is characterized in that the mixture containing possible other unsaturated monomers is passed in succession through four reaction zones giving a specific reaction temperature together with a chain transfer agent. This will be specifically described below.

The phenol-modified terpene resin used in the present invention is a resin having a structure represented by the above formula (1), an OH number of 150 or more and 250 and a number average molecular weight of 500 to 2,000.
This is because when the phenol-modified predetermined terpene oligomer is allowed to coexist with a relatively large amount of a monomer such as (meth) acrylic acid at a predetermined temperature in the presence of a chain transfer agent, This is based on the knowledge that, when copolymerizing with a monomer, the terpene oligomer exhibits a chain transfer effect and grafts onto a trunk made of a copolymer of these monomers.

  In the present invention, the use of a phenol-modified terpene resin having an OH value of 150 to 250 is an important factor that governs the efficiency of grafting, and the OH value is outside the above range. This is because the efficiency of grafting is drastically reduced. Therefore, in the present invention, it is more preferable to use a phenol-modified terpene resin having an OH value of 180 to 250.

In the present invention, the phenol-modified terpene resin having a number average molecular weight of 500 to 2,000 is used in order to increase the adhesive force of the formed coating film and ensure its strength. For this reason, in this invention, it is more preferable to use the phenol modified terpene resin of number average molecular weight (Mn) 500-1500.
In the phenol-modified terpene resin used in the present invention, the ratio (n) of the weight average molecular weight to the number average molecular weight is not particularly limited.

  The phenol-modified terpene resin used in the present invention can be obtained, for example, by reacting at least one terpene compound known as α pinene compound, β pinene compound and limonene with phenol or various phenol derivatives. it can. In the present invention, a commercially available phenol-modified terpene resin may be used, and examples thereof include Mighty Ace K-125 (manufactured by Yasuhara Chemical Co., Ltd.) or YP-902 (manufactured by Yasuhara Chemical Co., Ltd.).

  (Meth) acrylic acid, ester of (meth) acrylic acid, styrene, and unsaturated monomer copolymerizable with these used in the present invention constitute the core of the resulting copolymer, and the basic function of the coating film It is a monomer used for imparting. However, (meth) acrylic acid mainly plays a role in promoting the grafting of the phenol-modified terpene segment and imparting water solubility to the obtained graft copolymer. On the other hand, styrene plays a role of making the polymerization initiator unnecessary by causing the polymerization reaction to be performed using the polymerization heat in the polymerization reaction described later. This means that the polymerization rate in the polymerization reaction is relaxed and the reaction temperature can be easily controlled.

  The ester of (meth) acrylic acid used in the present invention is preferably a linear or branched (meth) acrylic alkyl ester or cycloalkyl ester having 1 to 18 carbon atoms, more preferably 3 to 18 carbon atoms. Or a hydroxyalkyl ester can be mentioned.

  Examples of the alkyl ester or cycloalkyl ester of (meth) acrylic acid include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, i-butyl acrylate, i Examples thereof include -butyl methacrylate, t-butyl acrylate, t-butyl methacrylate, cyclohexyl acrylate cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, lauryl acrylate, and lauryl methacrylate.

  Similarly, examples of the hydroxyalkyl ester of (meth) acrylic acid include 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, hydroxypropyl acrylate, and hydroxypropyl methacrylate.

  Examples of the unsaturated monomer copolymerizable with (meth) acrylic acid, (meth) acrylic acid ester and styrene used in the present invention include acrylamide, methacrylamide, N-methylacrylamide, vinyltoluene, vinyl acetate, Other vinyl monomers such as acrylonitrile or methacrylonitrile; or α, β-ethylenically unsaturated carboxylic acids such as itaconic acid or maleic acid; acrylates such as 2-acryloyloxyethyl succinic acid or 2-acryloyloxyethyl phthalic acid; Examples include methacrylates corresponding to these acrylates.

  In the present invention, (meth) acrylic acid, (meth) acrylic acid alkyl ester, cycloalkyl ester or hydroxyalkyl ester, optionally added unsaturated monomer copolymerizable with these, and styrene are mixed. Thus, a raw material mixture can be prepared.

  However, in the present invention, the total mixture of (meth) acrylic acid from the point of introducing a predetermined amount of carboxyl groups into the copolymer from which (meth) acrylic acid is obtained to impart desired water solubility. It is preferable that the content ratio (including these esters, styrene, phenol-modified terpene resins, and chain transfer agents) is large. Moreover, when the content rate with respect to the whole mixture of terpene resin becomes small, a desired tackifying effect will not be acquired.

  For this reason, in this invention, 15-35 weight% is preferable and, as for the content rate with respect to the whole mixture of (meth) acrylic acid, 20-30 weight% is especially preferable. Moreover, 1 to 20 weight% is preferable and, as for the content rate with respect to the whole mixture of the said phenol modified terpene resin, 5 to 15 weight% is more preferable. In the present invention, the content of other components is not particularly limited.

  In the present invention, the type of chain transfer agent to be used is not particularly limited. For example, styrene dimer, thioglycolic acid 2-ethylhexyl ester, 2-mercaptoethanol or t-dodecyl mercaptan can be used, and in particular, grafting is likely to occur. Styrene dimer and thioglycolic acid 2-ethylhexyl ester are preferred.

  On the other hand, in the present invention, as described above, a polymerization initiator is not required by performing radical thermal polymerization using thermal polymerization of styrene. This means that the polymerization rate is moderated by the polymerization reaction described later, and in the process of the present invention for producing a relatively low molecular weight polymer using a relatively large amount of acidic group monomer, the reaction within a predetermined range described later. Easy control of object temperature. That is, the graft copolymer produced in the present invention has a weight average molecular weight (Mw) of 10,000 or less, and the polymerization rate increases and the reaction temperature of the system rapidly rises with the normal bulk polymerization method. Easy to do. In addition, the presence of (meth) acrylic acid used in the present invention also tends to rapidly increase the reaction temperature of the system due to its characteristics as an acid monomer, increasing the polymerization rate. For this reason, in the present invention, by using the thermal polymerization of styrene as described above, a polymerization initiator is not required, thereby suppressing a rapid increase in the reaction temperature of the system and maintaining a predetermined reactant temperature described below. It is possible to do.

In the present invention, the obtained mixture is passed through a reaction zone including four first to fourth reaction zones that satisfy the following conditions in that order, preferably in that order, thereby copolymerizing the acrylic monomer. In this method, the copolymer is grafted with a phenol-modified terpene resin.

In the present invention, the reaction temperature (T _{1 to} T ₄ ) in the first to fourth reaction zones is set to 50 to 270 ° C. in order to cause terpene grafting at a high frequency. That is, in the present invention, the maximum temperature and the minimum temperature of the reactants in each reaction zone are important factors for terpene grafting, and if the temperature is outside the above temperature range, the frequency of terpene grafting decreases rapidly. To do.
Thus, reaction temperature of each reaction zone in the present invention (T ₁ ~T ₄₎ is more preferably 100 to 270 ° C., more preferably 140 to 270 ° C., particularly preferably from 150 to 270 ° C..

In the present invention, the reactant temperature (T _{1 to} T ₄ ) in each reaction zone is gradually increased as shown in the above relational expression. This is because the molecular weight of the coalescence is made as uniform as possible to obtain a graft copolymer having the desired water solubility and adhesiveness.

That is, in the bulk polymerization method of the present invention, the concentration of monomers such as acrylic acid is large and the viscosity of the system is low at the initial stage of polymerization. However, as the reaction proceeds, the consumption of monomers progresses and the viscosity of the system increases. When the reactant temperature in each reaction zone is made constant, the polymerization reaction rate of the monomer is higher in the reaction zone related to the initial polymerization, and the polymerization rate of the monomer is lower in the reaction zone related to the late polymerization. For this reason, when the reactant temperature in each reaction zone is constant, the resulting copolymer has a large variation in molecular weight, and a relatively large amount of graft copolymer having a small molecular weight and almost no acidic groups or terpene segments. It may generate | occur | produce and it may become water-insoluble as the whole copolymer, or may not have the desired adhesiveness.
Accordingly, in the present invention, a relatively large amount of (meth) acrylic acid monomer is contained in the raw material, and the reaction zone reactant temperature is increased as the monomer concentration decreases and the system viscosity increases during the polymerization reaction. And maintaining a substantially constant polymerization reaction rate in the entire polymerization process, introducing acidic groups and terpene segments into the copolymer at a certain ratio or more, so that the desired water-solubility and It is possible to impart adhesiveness.

In the present invention, from the above points, the reactant temperature (T ₁ ) in the first reaction zone is 50 ° C. to 160 ° C., and the reactant temperature (T ₂ ) in the second reaction zone is 70 ° C. to 190 ° C. Preferably, the reactant temperature (T ₃ ) in the third reaction zone is 70 ° C. to 250 ° C., and the reactant temperature (T ₄ ) in the fourth reaction zone is 70 ° C. to 270 ° C .; The reactant temperature (T ₁ ) in the reaction zone is 140-160 ° C., the reactant temperature (T ₂ ) in the second reaction zone is greater than 140 ° C. and less than 190 ° C., and the reactant temperature in the third reaction zone ( More preferably, T ₃ ) is 180-250 ° C. and the reactant temperature (T ₄ ) of the fourth reaction zone is 200-270 ° C .; the reactant temperature (T ₁ ) of the first reaction zone is 140- 160 ° C. and the reactant temperature (T ₂ ) in the second reaction zone is 170-190 ° C. More preferably, the reactant temperature (T ₃ ) in the third reaction zone is 200 to 250 ° C., and the reactant temperature (T ₄ ) in the fourth reaction zone is 230 to 270 ° C .; The reactant temperature (T ₁ ) of the second reaction zone is 150-160 ° C., the reactant temperature (T ₂ ) of the second reaction zone is 180-190 ° C., and the reactant temperature (T ₃ ) of the third reaction zone is 220. It is particularly preferred that the reaction temperature (T ₄ ) in the fourth reaction zone is 230 to 270 ° C.

In the present invention, the residence time of the reaction mixture in each reaction zone is preferably 5 to 20 minutes from the viewpoint of productivity and temperature control of each reaction zone. However, in order to make the polymerization reaction rate approximately constant between the reaction zones, it is preferable to change the residence time of the reaction mixture in each reaction zone depending on the reactant temperature in each reaction zone. When the temperature (T ₁ ) is 140 ° C. or higher and the reaction temperature (T _f ) in the final reaction zone is 200 ° C. or higher, it is preferably 5 to 10 minutes, more preferably 6 to 9 minutes. preferable. Conversely, when the reactant temperature (T ₁ ) in the first reaction zone is less than 140 ° C. and the reactant temperature (T ₄ ) in the fourth reaction zone is less than 200 ° C., it is preferably 12 to 20 minutes. More preferably, it is set to 15 to 20 minutes.

  In the production method of the present invention, a phenol-modified terpene resin having a number average molecular weight (Mn) of 500 to 2000 is styrene, (meth) acrylic acid, (meth) acrylic acid ester, and styrene or (meta ) Grafted onto a copolymer of other unsaturated monomers copolymerizable with acrylic acid or the like, and 0.174 to 0.486 mol / 100 g of acidic group monomer units with respect to the entire copolymer including a chain transfer agent, A terpene graft copolymer having a weight average molecular weight (Mw) of 1000 to 10,000 and a ratio (n) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of 1 to 5 can be obtained.

  The copolymer obtained by the present invention is grafted onto a copolymer of styrene and (meth) acrylic acid, etc., where the phenol-modified terpene resin, which is a viscosity-imparting segment, is a base segment that imparts basic properties of a coating film. In addition, each function in each segment is maintained at almost the same level as the case where each molecule is an independent molecule, and functions as a viscosity-imparting resin and a base resin. In addition, the molecular weight and the number of acidic groups of the phenol-modified terpene resin and the copolymer as a whole are converged to the specific range, and each copolymer is uniformly and completely dissolved in water by alkali neutralization. The coating film that is dissolved and formed using the aqueous solution has a film-forming property that cannot be achieved by a conventional coating composition having an aqueous adhesive function.

  The copolymer of the present invention provides a transparent aqueous solution upon neutralization and dissolution, can impart good film-forming properties to the formed coating film, and can also form a coating film excellent in tackiness. The weight average molecular weight Mw is preferably from 1000 to 10,000, particularly preferably from 1,000 to 6000. Moreover, the thing of ratio n (Mw / Mn) with respect to the number average molecular weight Mn of the weight average molecular weight Mw with respect to the same point is especially preferable 2-4.6.

  The dissolution of the copolymer of the present invention by alkali neutralization can be performed by, for example, dissolving the copolymer in an alkaline aqueous solution containing 4.7 to 7.8% by weight of ammonia.

  In addition, the alkali may be non-volatile such as caustic soda, but in terms of enhancing the solubility of the copolymer obtained in the present invention in water, ammonia or organic amines such as dimethylaminoethanol and triethanolamine Are preferred.

  In the aqueous coating composition having the adhesive function obtained by the alkali neutralization, the copolymer of the present invention functions as a base resin / tackifier resin. In other words, the base resin and the tackifier resin are the ultimate phase. It exists in a dissolved state and in a completely dissolved state. For this reason, if a coating film is formed with the aqueous coating composition of this invention, a uniform coating film can be obtained at a micro level.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, a following example does not limit this invention at all.

(Polymerization equipment)
The outline of the continuous polymerization apparatus used in the following Examples and Comparative Examples is shown in FIG. 1, and the enlarged portion of the stirring blade in the apparatus is shown in FIG. As shown in FIG. 1, the polymerization apparatus has a temperature sensor, a heating mantle, and an inner coil for cooling, and is a cylindrical reaction having an inner diameter of 100 to 150 mmφ and an inner height of 120 to 250 mm that are independently temperature controlled. The zone is continuously provided in the vertical direction of four reaction zones defined by a washer-like partition plate having an opening with a diameter of 40 to 80 mm in the center and a flange. Each reaction zone is equipped with a plurality of stirring blades each composed of a 40 to 100 mmφ disk and a paddle blade of the same diameter mounted on the disk and capable of stirring at 50 to 700 revolutions. In order from the top, the reaction temperature is set to 50 to 160 ° C. for the first reaction zone, 70 to 190 ° C. for the second reaction zone, 70 to 250 ° C. for the third reaction zone, and 70 to 270 ° C. for the fourth reaction zone. In order to be able to control, it has a temperature sensor, a heating jacket that cools and cools by a signal from the temperature sensor, and a cooling inner coil. A liquid level gauge is installed in the uppermost first reaction zone, and it is possible to continuously polymerize by constantly supplying the monomer equivalent to the amount of resin taken out from the lowermost part while keeping the internal volume constant. It has become. It also has a supply phone that supplies the reactants from the top at a pressure of 0.05 MPa to 5 MPa.

(Evaluation methods)
(1) Transparency of solution The resin obtained in each Example and Comparative Example was placed in alkaline water with the following composition, and the transparency of the solution was examined with the naked eye. If transparent, terpene grafting occurred frequently. It was judged that.
Resin obtained in each example and comparative example 30.0 parts by weight 25% ammonia water 17.5 parts by weight Water 52.5 parts by weight

(2) Transparency of the dried coating film The solution of (1) above was applied to a glass plate with a heating residue (TNV) of 30.7% with a 10 mil applicator, dried at 150 ° C for 30 minutes and dried. A membrane was obtained. The transparency of the obtained dried coating film was judged by the naked eye, and if it was transparent, it was judged that grafting of terpenes occurred frequently.

(3) Molecular weight (Mw, Mn and Mw / Mn)
The weight average molecular weight (Mw), number average molecular weight (Mn), and Mw / Mn were measured with a GPC measuring instrument (Hitachi Model 139) using polystyrene as a reference substance.

[Example 1]
In the continuous polymerization machine shown in FIG. 1, 40.8 parts by weight of styrene, 17.5 parts by weight of butyl acrylate, 25.1 parts by weight of acrylic acid, terpene phenol resin (OH number 210, Mw: 1700, Mighty Ace K-125) 8.3 parts by weight of Yashara Chemical Co., Ltd.) and 8.3 parts by weight of a chain transfer agent (styrene dimer, trade name: NOFMER MSD, manufactured by NOF Corporation), and charged at 150 ° C. in the first reaction zone. For 8 minutes at 180 ° C. in the second reaction zone, 8 minutes at 220 ° C. in the third reaction zone and 8 minutes at 250 ° C. in the fourth reaction zone. A resin having a polymerization rate of 93.4%, Mw: 2,650, and Mw / Mn (n): 3.5 was produced. When 30.0 parts by weight of this resin was mixed and dissolved together with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, a completely transparent aqueous solution was obtained with a heated fraction (TNV) of 30.7. %, The viscosity was 11,140 mPa · s. Then, when this aqueous solution was baked at 150 ° C. for 30 minutes to form a coating film, the formed coating film was completely transparent, indicating that the water-soluble acrylic resin and the terpene resin were completely compatible. It was.

[Example 2]
7. 31.0 parts by weight of styrene, 31.0 parts by weight of 2-ethylhexyl acrylate, 26.5 parts by weight of acrylic acid, terpene phenol resin (OH number 210, Mw: 1700, Mighty Ace K-125, manufactured by Yasuhara Chemical Co., Ltd.) 8 parts by weight of a mixture of 2.7 parts by weight of a chain transfer agent (2-ethylhexylthioglycolic acid, manufactured by Daisail Chemical Co., Ltd.) in the first reaction zone at 150 ° C. for 8 minutes and in the second reaction zone at 180 ° C. for 8 minutes. And continuous polymerization was carried out under the condition that the reaction was held at 220 ° C. for 8 minutes in the third reaction zone and at 250 ° C. for 8 minutes in the fourth reaction zone. A resin having a polymerization rate of 92.5%, Mw: 5,240, and Mw / Mn (n): 3.3 was produced. When 30.0 parts by weight of this resin was mixed and dissolved with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, a completely transparent aqueous solution was obtained, and the heated fraction (TNV) was 30.1%. The viscosity was 7,660 mPa · s. Then, when this aqueous solution was baked at 150 ° C. for 30 minutes to form a coating film, the formed coating film was completely transparent, indicating that the water-soluble acrylic resin and the terpene resin were completely compatible. .

[Example 3]
39.8 parts by weight of styrene, 17.1 parts by weight of 2-ethylhexyl acrylate, 24.4 parts by weight of acrylic acid, terpene phenol resin (OH number 250, Mw: 1098, YP-902, manufactured by Yasuhara Chemical Co., Ltd.) 16.3 parts by weight Part of a chain transfer agent (2-ethylhexylthioglycolic acid, manufactured by Daicel Chemical Industries, Ltd.) 2.4 parts by weight in a first reaction zone at 150 ° C. for 8 minutes, in a second reaction zone at 180 ° C. for 8 minutes, Continuous polymerization was carried out under the condition of staying in the third reaction zone at 220 ° C. for 8 minutes and in the fourth reaction zone at 250 ° C. for 8 minutes. A resin having a polymerization rate of 95.0%, Mw: 5,224, and Mw / Mn (n): 4.0 was produced. When 30.0 parts by weight of this resin was mixed and dissolved with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, a completely transparent aqueous solution was obtained, and the heated fraction (TNV) was 30.5%. The viscosity was 78,500 mPa · s. Then, when this aqueous solution was baked at 150 ° C. for 30 minutes to form a coating film, the formed coating film was completely transparent, indicating that the water-soluble acrylic resin and the terpene resin were completely compatible.

[Example 4]
Styrene 42.6 parts by weight, butyl acrylate 18.3 parts by weight, acrylic acid 26.1 parts by weight, terpene phenol resin (OH value 250, Mw: 1098, YP-902, manufactured by Yashara Chemical Co., Ltd.) 4.3 parts by weight , 8.7 parts by weight of a styrene dimer (Nofmer MSD, manufactured by NOF Corporation), 8 minutes at 150 ° C. in the first reaction zone, 8 minutes at 180 ° C. in the second reaction zone, and 220 in the third reaction zone. Continuous polymerization was carried out under the conditions of 8 minutes at 0 ° C. and 8 minutes at 250 ° C. in the fourth reaction zone. A resin having a polymerization rate of 97.5%, Mw: 2,879, and Mw / Mn (n): 3.8 was produced. When 30.0 parts by weight of this resin was mixed and dissolved with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, a completely transparent aqueous solution was obtained, and the heated fraction (TNV) was 30.3%. The viscosity was 3,620 mPa · s. Then, when this aqueous solution was baked at 150 ° C. for 30 minutes to form a coating film, the formed coating film was completely transparent, indicating that the water-soluble acrylic resin and the terpene resin were completely compatible. .

[Example 5]
Styrene 39.8 parts by weight, butyl acrylate 17.1 parts by weight, acrylic acid 24.4 parts by weight, terpene phenol resin (OH number 210, Mw: 1700, Mighty Ace K-125, manufactured by Yasuhara Chemical Co., Ltd.) 16.3 Part by weight of a mixture of 2.4 parts by weight of chain transfer agent (2-ethylhexylthioglycolic acid, manufactured by Daisail Chemical Co., Ltd.) in the first reaction zone at 130 ° C. for 15 minutes and in the second reaction zone at 140 ° C. for 15 minutes. The polymer was continuously polymerized under the condition that the third reaction zone was kept at 160 ° C. for 15 minutes and the fourth reaction zone was kept at 180 ° C. for 15 minutes (the maximum temperature was kept at 180 ° C. compared to Examples 1 to 4, and the reaction time was reduced). 2 times longer than in Example 1). When 30.0 parts by weight of this resin was mixed and dissolved with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, it became slightly cloudy and was not completely transparent. The aqueous solution had a heated fraction (TNV) of 22.6% and a viscosity of 2,428 mPa · s. Thereafter, this aqueous solution was baked at 150 ° C. for 30 minutes to form a coating film. As a result, the formed coating film was also thinly clouded. This is probably because the reaction temperature was low and the acrylic grafting reaction to the terpene resin did not occur frequently.

[Comparative Example 1]
8.3 parts by weight of terpene phenol resin (OH number 210, Mw: 1700, Mighty Ace K-125, manufactured by Yasuhara Chemical Co., Ltd.) was dissolved in 19.4 parts by weight of MEK. To this, 33.2 parts by weight of an aqueous solution obtained by dissolving 1.0 part by weight of a surfactant Newcol-707SF (manufactured by Nippon Emulsifier Co., Ltd.) in 32.2 parts by weight of water was added while stirring in a flask with a separation trap. It heated at 80 degreeC, MEK was distilled off and the aqueous emulsion in which the terpene phenol resin was disperse | distributed to fine particle form was obtained. Next, in the continuous polymerization machine used in Example 1, 44.5 parts by weight of styrene, 19.1 parts by weight of butyl acrylate, 27.3 parts by weight of acrylic acid, and styrene dimer (Nofmer MSD, manufactured by NOF Corporation) ) 9.1 parts by weight of the mixture, 8 minutes at 150 ° C. in the first reaction zone, 8 minutes at 180 ° C. in the second reaction zone, 8 minutes at 220 ° C. in the third reaction zone, 250 minutes in the fourth reaction zone Polymerization was continuously carried out under the condition of retaining at 8 ° C. for 8 minutes. A resin having a polymerization rate of 96.6%, Mw: 6,113, and Mw / Mn (n): 4.3 was produced. When 30.0 parts by weight of this resin was mixed and dissolved with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, a completely transparent aqueous solution was obtained, and the heated fraction (TNV) was 30.1. %, The viscosity was 542 mPa · s. Thereafter, 13.6 parts by weight of a terpene phenol resin fine particle dispersion was added to 100 parts by weight of this acrylic resin aqueous solution to obtain an emulsion. The coating film obtained by baking this emulsion aqueous solution at 150 ° C. for 30 minutes is more cloudy than the coating film formed in Example 5, indicating that the water-soluble acrylic resin and the terpene resin are not compatible.

[Comparative Example 2]
8.3 parts by weight of terpene phenol resin (Mw: 250, YP-902, manufactured by Yasuhara Chemical Co., Ltd.) was dissolved in 19.4 parts by weight of MEK. To this, 33.2 parts by weight of an aqueous solution obtained by dissolving 1.0 part by weight of a surfactant Newcol-707SF (manufactured by Nippon Emulsifier Co., Ltd.) in 32.2 parts by weight of water was added while stirring in a flask with a separation trap. It heated at 80 degreeC, MEK was distilled off and the aqueous emulsion in which the terpene phenol resin was disperse | distributed to fine particle form was obtained. Next, in the continuous polymerization machine used in Example 1, 47.5 parts by weight of styrene, 20.4 parts by weight of 2-ethylhexyl acrylate, 29.2 parts by weight of acrylic acid, a chain transfer agent (2-ethylhexyl thioglycolic acid, Daicel). (Chemical Industry Co., Ltd.) 2.9 parts by weight of the mixture was added to the first reaction zone at 150 ° C. for 8 minutes, the second reaction zone at 180 ° C. for 8 minutes, the third reaction zone at 220 ° C. for 8 minutes, Continuous polymerization was carried out under conditions where the reaction zone was kept at 250 ° C. for 8 minutes. Polymerization rate: 94.1%, Mw: 4,066, Mw / Mn (n): 3.5 resin was produced. When 30.0 parts by weight of this resin was mixed and dissolved with 17.5 parts by weight of 25% aqueous ammonia and 52.5 parts by weight of water, a completely transparent solution was obtained. This aqueous solution had a heated fraction (TNV) of The viscosity was 30.1% and the viscosity was 542 mPa · s. Thereafter, 13.6 parts by weight of a terpene phenol resin fine particle dispersion was added to 100 parts by weight of this aqueous resin solution to obtain an emulsion. The coating film obtained by baking this emulsion aqueous solution at 150 ° C. for 30 minutes was more cloudy than the coating film obtained in Example 5, indicating that the water-soluble acrylic resin and the terpene resin were not compatible. .

[Comparative Example 3]
42.6 parts by weight of styrene, 18.3 parts by weight of butyl acrylate, 26.1 parts by weight of acrylic acid, 4.3 parts by weight of aromatic modified terpene resin (Mw: 800, YS Resin TO-125, manufactured by Yasuhara Chemical Co., Ltd.) , 8.7 parts by weight of a styrene dimer (Nofmer MSD, manufactured by NOF Corporation), 8 minutes at 150 ° C. in the first reaction zone, 8 minutes at 180 ° C. in the second reaction zone, and 220 in the third reaction zone. Continuous polymerization was carried out under the conditions of 8 minutes at 0 ° C. and 8 minutes at 250 ° C. in the fourth reaction zone. When the produced resin was dissolved in aqueous ammonia, it showed strong white turbidity and did not dissolve. This shows that the graft reaction to the acrylic copolymer did not occur by using the aromatic modified terpene resin instead of the terpene phenol resin.

[Comparative Example 4]
42.6 parts by weight of styrene, 18.3 parts by weight of butyl acrylate, 26.1 parts by weight of acrylic acid, 4.3 parts by weight of terpene-based hydrogenated resin (Mw: 700, Clearon P-125, manufactured by Yashara Chemical), styrene dimer (NOFMER MSD) A total of 115 parts by weight of 8.7 parts by weight of the mixture was added to the first reaction zone at 150 ° C. for 8 minutes, the second reaction zone at 180 ° C. for 8 minutes, and the third reaction zone at 220 ° C. for 8 minutes. And was allowed to stay at 250 ° C. for 8 minutes in the fourth reaction zone. As a result, when the polymerized resin was dissolved in aqueous ammonia, it was strongly clouded and did not dissolve. This indicates that the graft reaction to the acrylic copolymer did not occur by using a terpene hydrogenated resin instead of the terpene phenol resin.

The evaluation results of the raw material compositions and the obtained aqueous coating compositions in the above Examples and Comparative Examples are summarized in Table 1 below.

(Evaluation)
In Examples 1 to 5 using a phenol-modified terpene resin, the terpene resin is grafted to various acrylic copolymers, but in Comparative Examples 3 and 4 using a terpene having no phenolic OH, the terpene resin is grafted. I did not. However, in Example 5 in which the reaction temperature in each reaction zone was 130 to 180 ° C, the frequency of grafting was reduced compared to Examples 1 to 4 in which the reaction temperature in each reaction zone was 150 to 250 ° C. The superiority of the temperature conditions in Examples 1 to 4 was recognized. In Example 1 and Comparative Example 1 in which the raw material compositions used were substantially the same, the weight average molecular weight (Mw) of the obtained copolymer was significantly smaller in Example 1 than in Comparative Example 1, and this fact Also demonstrates that polymer radical termination by the phenol-modified terpene, ie, grafting, occurs frequently.

  As described above, the production method of the present invention comprises a water-soluble acrylic terpene copolymer having both functions of a tackifying resin and a base resin, and an aqueous coating having a function of an adhesive comprising the same as an active ingredient. The composition can be produced, and a film-forming property that is unprecedented in an aqueous coating composition having an environment-adaptive adhesive function can be imparted. Therefore, it can be widely applied to coating compositions that require desired adhesive properties as well as properties as a base resin, such as water-based inks, paints, coating agents, adhesives, and pressure-sensitive adhesives.

It is a schematic diagram which shows the structure of the continuous polymerization apparatus used by the Example and the comparative example. It is an enlarged view which shows typically the part of the stirring blade in the apparatus shown in FIG.

Claims (10)

The repeating unit is represented by the following formula (1):

[Wherein, m and n represent an integer of 1 or more]
At least one phenol-modified terpene resin having a structure represented by formula (II) and having an OH number of 150 to 250 and a number average molecular weight of 500 to 2,000,
Acrylic acid and / or methacrylic acid (hereinafter collectively referred to as “(meth) acrylic acid”), esters of (meth) acrylic acid, styrene, and optionally added unsaturated monomers copolymerizable with these Together with a chain transfer agent,
The phenol-modified terpene resin is more than 0 with respect to the total amount of the phenol-modified terpene resin, the (meth) acrylic acid, the ester of (meth) acrylic acid, the styrene, the unsaturated monomer, and the chain transfer agent. Less than% by weight, mixed in a composition ratio containing 15 to 35% by weight of the (meth) acrylic acid,
The obtained mixture is passed through four reaction zones that give a mixture temperature of T _{1 to} T _{4 that} satisfy the following conditions without using a polymerization initiator in this order. method for producing a terpene ring rAFT copolymer.

[Wherein T ₁ is the reactant temperature in the first reaction zone, T ₂ is the reactant temperature in the second reaction zone, T ₃ is the reactant temperature in the third reaction zone, and T ₄ is It is the reactant temperature in the fourth reaction zone] The reaction temperature of each reaction zone (T ₁ through T ₄₎ is a one hundred forty to two hundred seventy ° C., the production method of acrylic terpene graft copolymer of claim 1. The reaction temperature _{(T 1, T 2, T} 3, T 4) satisfy the following condition for each reaction zone, the production method of acrylic terpene graft copolymer of claim 1.

The reactant temperature (T ₁ ) in the first reaction zone is 140-160 ° C., the reactant temperature (T ₂ ) in the second reaction zone is 170-190 ° C., and the reactant in the third reaction zone temperature (T ₃₎ is the 200 to 250 ° C., the fourth reaction zone the reactants temperature (T ₄₎ is the 230 to 270 ° C., the production method of acrylic terpene graft copolymer according to claim 3 .   The manufacturing method of the acrylic terpene graft copolymer as described in any one of Claims 1-4 whose residence time in the said reaction zone is 5 to 20 minutes.   The manufacturing method of the aqueous coating composition which has the function of an adhesive agent including the process of neutralizing and melt | dissolving the obtained copolymer with alkaline water after the process of Claims 1-5.   A water-soluble acrylic terpene graft copolymer obtained by the method according to claim 1. An aqueous coating composition in which the water-soluble acrylic terpene graft copolymer according to claim 7 is dissolved in alkaline water.   An aqueous coating composition obtainable by the method of claim 6 The aqueous coating composition according to claim 8 or 9 , which is used for an application selected from the group consisting of an ink, a paint, an adhesive, and an adhesive.

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