JPS592697B2 - Novel emulsion composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to novel emulsion compositions, more particularly polyisoprene latex or j5 styrene-
An emulsion composition with improved adhesive and adhesive properties, comprising a conjugated diene copolymer rubber latex and a hydrocarbon resin or derivative thereof containing 1,3-pentadiene, α-methylstyrene, and cyclopentene as main components. Regarding.

A typical application of tackifier resins such as rosin resins and petroleum resins is in the field of adhesives, and in this field, organic solvent solution type adhesives have traditionally been used extensively. However, in the case of solution-type adhesives, it is necessary to reduce the molecular weight of solid natural rubber or synthetic rubber by mastication or other means to make it easier to dissolve in organic solvents. As a result, the inherent cohesive force of the rubber decreases, and the aging resistance is adversely affected. Furthermore, since a large amount of organic solvent is required, there are problems in terms of safety and health and pollution during the manufacturing process, and solvent recovery equipment is required to prevent these problems. These drawbacks are not limited to pressure-sensitive adhesives, but are the same in the fields of adhesives, paints, and inks, and as a result, there has been a strong demand for so-called solvent removal, and recently, emulsion-based methods have been attracting attention. That is, since water is used as a dispersion medium in the emulsion method, it is possible to avoid the above-mentioned dangers due to the use of solvents, and the following advantages are also provided. First, since there is no need for solvent recovery or mastication of solid rubber, there are advantages in manufacturing soil, such as simplifying manufacturing equipment and saving power.

Furthermore, since high-molecular-weight rubber can be used without mastication, it is possible to obtain an adhesive that has superior cohesive force and adhesive strength and good aging resistance compared to a solution-type adhesive. Furthermore, since rubber latex is used, a dispersion liquid with a higher concentration and lower viscosity than a solvent solution can be obtained. Many methods of using rubber latex as a rubber component have been known so far (Japanese Patent Publication No. 351830, No. 21112/1973, etc.), but these conventional techniques rely on natural raw materials such as tackifiers. Rosin-based resins were prized.

In response, attempts have been made to replace petroleum resins made from petroleum fractions, but these petroleum resins are difficult to emulsify or have poor stability after emulsification, resulting in separation from the aqueous phase. Or, when mixed with rubber latex, it has poor mixing stability, such as separation or coagulation, and even if these drawbacks could be solved, the tack imparting effect is small, and it is not sufficient as an adhesive or adhesive. It did not provide any good performance. The present inventors have carried out intensive studies to provide a hydrocarbon resin emulsion that eliminates these drawbacks, and as a result, a novel hydrocarbon resin containing 1,3-pentadiene, α-methylstyrene, and cyclobenzene as main components has been developed. The resin or the modified resin obtained by modifying it is extremely superior in terms of ease of emulsification, stability after emulsification, and stability when mixed with rubber latex, and is also superior to rosin in terms of adhesive properties. It exhibits performance comparable to other resins, has a light color and excellent appearance, and has the cohesive strength of rubber. The purpose of the present invention is to provide an emulsion composition suitable as an aqueous pressure-sensitive adhesive and an adhesive. (4) For 100 parts by weight of the solid content of polyisoprene latex or styrene-conjugated diene copolymer latex, (B) 1.3
- 45-85% by weight of pentadiene units, 10-45% by weight of α-methylstyrene units, 3-2 cyclobenzene units
0% by weight and 0-20% by weight of 1,3-butadiene units
At least one resin having a softening point of 50 to 170° C. selected from a hydrocarbon resin containing the hydrocarbon resin, an adduct of the hydrocarbon resin with an ethylenically unsaturated carboxylic acid or its anhydride, or a derivative of the adduct is hardened. This can be achieved by blending 5 to 250 polymer parts in terms of type.

The rubber latex used in the present invention is a latex of polyisoprene rubber or styrene-conjugated diene copolymer rubber. Specifically, natural rubber, synthetic cis-1.4 polyisoprene rubber, styrene-butadiene copolymer rubber,
These latexes include styrene-isoprene copolymer rubber, styrene-butadiene block copolymer rubber, and styrene-isoprene block copolymer rubber, which can be synthesized directly by emulsion polymerization or obtained by solution polymerization. It may also be obtained by phase inversion of rubber obtained by copolymerizing with other comonomers (for example, unsaturated carboxylic acid, unsaturated carboxylic acid ester, unsaturated nitrile, etc.)
It may be modified by appropriately copolymerizing or graft polymerizing. Among these rubbers, polyisoprene rubber is most suitable in terms of performance, and natural rubber lattetus is particularly excellent. On the other hand, the tackifier used in the present invention has 1.3-
45-85% by weight of pentadiene units, 10-45% by weight of α-methylstyrene units, 3-20% of cyclobenzene units
Softening point 60-140 containing 0-20% by weight, preferably 2-15% by weight of 1,3-butadiene units
℃, preferably 60 to 12 ℃ hydrocarbon resin,
Such hydrocarbon resins include 1,3-pentadiene 35-8
5% by weight, α-methylstyrene 10-50% by weight, cyclobenzene 5-30% by weight, and 1,3-butadiene O~
It is prepared by copolymerizing a monomer mixture containing 15% by weight, preferably 2 to 10% by weight, in the presence of a Friedel-Grafts type catalyst.

The emulsion composition of the present invention using such a hydrocarbon resin may contain a binary copolymer of 1,3-pentadiene and cyclobenzene or a binary copolymer of 1,3-pentadiene and α-methylstyrene. It has much better adhesion performance than the previous one.

In addition to the three components of 1.3-pentadiene, α-methylstyrene, and cyclobenzene, this adhesive property also has 1.3-
Further improvement can be achieved by using a quaternary copolymer copolymerized with butadiene. However, if the content of α-methylstyrene units or cyclobenzene units becomes too large, the softening point decreases, which is undesirable. Similar results will be obtained if the amount exceeds 20% by weight, so it is necessary to keep the composition of the hydrocarbon resin within the above range.

However, as long as the composition of the hydrocarbon resin is within the above range, it is also possible to use a resin copolymerized with other comonomers that can be copolymerized within a range that does not essentially impede the effects of the present invention. Examples of such resins include those obtained by copolymerizing the above-mentioned monomer mixture with other aliphatic or alicyclic monoolefins or diolefins having 4 to 10 carbon atoms. Among possible comonomers, when using resins copolymerized with diolefins such as isoprene, cyclopentadiene, and synchropentadiene, there is a marked tendency to impair the adhesive performance of the adhesive composition. The content must be less than 5% by weight. The acid-modified hydrocarbon resin used in the present invention can be easily produced by a known method of reacting the hydrocarbon resin as described above with an ethylenically unsaturated carboxylic acid or its anhydride. Ethylenically unsaturated carboxylic acids or anhydrides thereof to be subjected to the reaction include acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid, maleic anhydride, itaconic anhydride, and citraconic anhydride. α with carbon number of 8 or less, such as. β-monounsaturated carboxylic acid or its anhydride and 3.6-endomethylene-1.
2.3. Conjugated dienes such as 6-tetrahydrophthalic anhydride and α. Examples include Teils-Alda addition reaction products with β-unsaturated carboxylic acids or their anhydrides, and these may be used alone or in combination of two or more. Among these, maleic anhydride is prized for its ease of reaction and quality. The reaction between hydrocarbon resin and ethylenically unsaturated carboxylic acid or its anhydride is
Usually 5 minutes to 20 hours at a temperature of 50 to 30 °C, diluent,
It is carried out in the presence or absence of a gelling inhibitor and a reaction accelerator.

The amount of ethylenically unsaturated carboxylic acid or its anhydride used in this reaction is within a range that allows the saponification value of the acid-modified hydrocarbon resin to be adjusted to 200 or less, preferably 100 or less. When maleic anhydride is used as the saturated carboxylic anhydride, it is used in a proportion of 20 parts by weight or less per 100 parts by weight of the resin. Further, in the present invention, derivatives obtained by further modifying the acid-modified hydrocarbon resin can also be used.

For example, ester-modified hydrocarbon resins are produced by converting acid-modified hydrocarbon resins into monohydric alcohols such as methanol, ethanol, propanol, and butanol, and polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, and glycerin. It is easily obtained by esterification with alkali or alkaline earth metal compounds such as caustic soda, caustic potash, slaked lime, etc., and amines such as ammonia, methylamine, diethylamine, ethylenediamine, hexamethylenetetramine, ethanolamine, etc. An alkali or alkaline earth metal salt or an amine salt can be obtained by reacting with the amine salt, and any derivative thereof can be used. However, when using these derivatives, the color tone is slightly more difficult than when using unmodified hydrocarbon resins, and the tackiness and adhesion properties also tend to decrease slightly. It is also preferable to use resin. In order to emulsify these hydrocarbon resins, it is preferable to dissolve the hydrocarbon resin in an organic solvent to lower the viscosity to an appropriate level, and then add an emulsifier to emulsify it in water. Emulsion from which the solvent is removed produces more favorable results in the sense that it avoids the disadvantages caused by solvents. Another method is to emulsify at high temperature under pressure that does not cause water to boil, or to dilute the hydrocarbon resin with a high boiling point liquid such as a plasticizer. When blending into stable rubber latex, it is also possible to directly blend and emulsify the organic solvent solution of the tackifying resin into the rubber latex without emulsifying it. The emulsifier used is not particularly limited as long as it can form a stable emulsion of hydrocarbon resin, and specific examples include anionic emulsifiers such as fatty acid soaps, rosin acid soaps, alkylbenzene sulfonates, and polyesters. Examples include nonionic emulsifiers such as oxyethylene alkyl ether, polyoxyethylene aryl ether, and polyoxyethylene alkyl ester.

In this case, when using a nonionic emulsifier, it is preferable that the HLB (hydrophilicity lipophilicity balance) is in the range of 13 to 19, and if the nonionic emulsifier is outside this range, the stability tends to decrease. be. Among these emulsifiers, it is preferable to use rosin acid soap because it does not impair the effect of imparting tackiness. The amount of emulsifier used is the amount necessary to make a stable emulsion, and is usually 0.5 to 1 emulsifier per 100 parts by weight of hydrocarbon resin.
0 parts by weight, preferably in the range of 1 to 5 parts by weight. The emulsion composition of the present invention has a solid content of rubber latex of 1
It is obtained by blending 5 to 250 parts by weight, preferably 10 to 200 parts by weight, of an emulsion of an adhesion agent to 00 parts by weight.

At this time, if the amount of adhesive agent added is small, for example, 50
When the amount is less than 1 part by weight, it is mainly useful as an adhesive, and when it is more than 1 part by weight, it is mainly useful as an adhesive. In addition, materials such as plasticizers, anti-aging agents, fillers, thickeners, and emulsion stabilizers such as protective colloids can also be used in the emulsion composition of the present invention, and these materials are also preferred. is formulated as an aqueous dispersion.

The present invention will be explained in more detail with reference to Examples below.

Note that all parts used in Examples and Reference Examples are based on weight. Reference Example 1 Various hydrocarbon resins having the properties shown in Table 1 are produced by copolymerizing a monomer mixture containing 1,3-pentadiene as a main component in a benzene solvent using aluminum chloride as a catalyst. was manufactured.

The softening point was measured in accordance with the ring and ball method specified in JIS K-2531, and the structural units in the polymer were calculated by analyzing and comparing the charged monomer composition and the recovered unreacted monomer composition. After 100 parts of the three types of hydrocarbon resins shown in Table 2 were placed in a glass flask and heated to 200°C to melt, maleic anhydride in the amount shown in Table 2 was added and reacted for 1 hour. After the reaction was completed, the molten resin was taken out and the softening point of the resin was measured. The results. Shown in Table 2. Reference Example 3 Part of the acid-modified resin ClOO obtained in Reference Example 2 was placed in a glass flask and heated and melted at 230°C, and then 10 parts of tri-n-butylamine was added little by little over 30 minutes, and the mixture was further reacted for 1 hour.

After the reaction, the molten resin was taken out to obtain the amine salt of the acid-modified resin (modified resin C).The softening point was 95°C. Reference Example 4 The acid-modified resin ClOO portion obtained in Reference Example 2 was After the mixture was placed in a glass flask and heated to 230°C to melt, 3 parts of potassium hydroxide was added over 30 minutes while dehydrating, and the mixture was further reacted for 1 hour as a post-reaction.

After the reaction was completed, the molten resin was taken out to obtain a potassium salt of acid-modified resin (modified resin CP). The softening point was 120°C. Example 1 The hydrocarbon resin obtained in the reference example and various commercially available tackifying resins as comparative examples were emulsified by the following method, and their emulsifying properties and emulsion stability were investigated.

First, 6 parts of a 25% potassium rosinate aqueous solution was added to a solution of 100 parts of a sample hydrocarbon resin dissolved in 30 parts of toluene, and the mixture was thoroughly stirred and mixed.

Next, 35 parts of a previously prepared 18% ammonium casein aqueous solution was added with stirring, and after thorough mixing, 79 parts of water was gradually added and stirred at high speed to transform the water-in-oil emulsion into an oil-in-water emulsion. The phase was changed to Immediately after emulsification, several drops of the resulting emulsion were dropped into water to observe its dispersibility.
Those with excellent emulsifying properties were quickly dispersed in water. The emulsion stability was determined by observing the state of the emulsion after emulsification for 2 hours and after being left for 1 day, that is, the presence or absence of separation, and observing the surface state, and by observing the state of the emulsion when it was diluted with water to 10% and left for 1 day after emulsification. The results are shown in Table 3. As seen in Table 3, the hydrocarbon resin according to the present invention is easy to emulsify and has excellent emulsion stability, similar to the rosin derivative (Ester Gum H) cited as a control example.

However, as seen in the control example, hydrocarbon resins that do not contain α-methylstyrene or have a small content (F and G) and aliphatic hydrocarbon resins such as Escorets 1103u are difficult to emulsify or the emulsion is unstable. It is. Further, aromatic hydrocarbon resins such as Nisseki Neopolymer 120 can be emulsified, but have poor emulsion stability and lack the ability to impart tack. Example 2 Natural rubber latex (GuthrieLatex manufactured by Glthrle CO.
High ammonia type, rubber content 60%) was added to the emulsion obtained in Example 1, and the mixture was left to age at 35° C. for 20 hours.

Thereafter, it was allowed to cool to room temperature and passed through an 80-mesh wire mesh, and the filterability and presence of coagulum were observed at this time, and the aging stability was examined. Next, the finished emulsion was applied to a stretched polypropylene film having a thickness of 80 .mu.m to give a glue thickness of 35 to 45 .mu.m, and dried at 90.degree. C. for 5 minutes. The adhesive film thus obtained was cut to a width of 25 m and 71 L, and the holding force, 180 degree peeling force and adhesive force of this tape were measured at 25°C and 40°C.
℃, 5℃, and 25℃ after heat aging at 65℃ for 72 hours. The holding force is JIS Zl.
25m77 on a stainless steel plate polished with No. 280 waterproof abrasive paper according to 524! X2577! The samples were pasted so that the areas of l were in contact, a load of 1 kg was applied at 25°C, the deviation distance was measured and displayed after 60 minutes and 90 minutes, and the 180 degree peeling force was processed in the same manner according to JIS Zl522. The adhesion was measured by pasting it on a stainless steel plate with a width of 25 mm x length of 100 mm and peeling it off in a direction of 180 degrees at a speed of 200 mTL/min on a 25 plate C, and the adhesion was measured according to J. DOw
Law [PrOc. Inst. Rub. Ind. , lO5(
1954)], from 1/32 inch in diameter to 1 in.
Stainless steel balls of 32 different sizes up to inches were rolled at an initial speed of 0 and the size of the ball with the largest diameter that stopped on the adhesive tape was indicated.

The results are shown in Table 4. As seen in Table 4, the emulsion composition of the present invention contains a rosin derivative (Ester Gum H).
), it exhibits comparable adhesion performance, and also exhibits superior holding power at high temperatures (40°C).

It also maintains excellent adhesion even at low temperatures (5°C).
The tackifier resin given as another control example had poor adhesive performance, showing almost no tackiness especially at low temperatures, so no measured value could be obtained. Example 3 Using the emulsion obtained in Example 1 in the same manner as in Example 2, natural rubber latex was converted into styrene-butadiene copolymer latex (NipOl485O) manufactured by Nippon Zeon Co., Ltd., total solid content 64.
%), an adhesive tape test was conducted.

The results are shown in Table 5. As shown in Table 5, the emulsion of styrene-butadiene copolymer latex also exhibits adhesion properties comparable to those using rosin derivatives, and has superior performance due to its holding power at high temperatures (40°C). ing.

Example 4 The emulsion obtained in Example 1 is added to natural rubber latex (same as in Example 2) and left at 50°C for 12 hours.

Thereafter, it was applied to a plain weave strong human silk cloth of 2 (I-J Mo V! x 9 cm) by brush coating, and after drying at 40°C for 30 minutes, they were bonded together. Then, they were crimped twice with a 3 kg roll, (Cut to V7l width. After being left at room temperature for 20 minutes, a 180 degree peel test was performed to check the self-adhesion strength.

In addition, a test was conducted in which woven fabrics coated with the mixed solution in the same manner were laminated together after drying at 40°C for 30 minutes, then crimped 6 times back and forth with a 5 kg roll, immediately cut into 1-width pieces, and laminated together. A load of 100 g was suspended from one of the pieces in the peeling direction at an angle of about 180 degrees, and the piece was allowed to stand for 5 minutes in a dryer at 120° C., and then the peeling distance was measured to determine the degree of heat-resistant adhesion.

The results are shown in Table 6. As shown in Table 6, the emulsion composition of the present invention provides a self-adhesive strength comparable to that when a rosin derivative is used, and also has a tendency to reduce the cohesive strength of natural rubber in terms of heat-resistant tack. It can be seen that the cohesive force not only does not decrease but also increases at low blending ratios. Example 5 The emulsion of tackifying resins B and C obtained in Example 1 was
They were mixed in a ratio of 1:1 and left to age at room temperature for 12 hours.

40 parts (solid content) of the obtained mixed emulsion was mixed with 100 parts (solid content) of various rubber latexes shown in Table 7, and the mixture was left to mature at room temperature for 24 hours to prepare a paste and conduct an adhesion test. The test piece has a thickness of 2 mm, a width of 20 m, a length of 60 m, and a length of 60 m.
Using a cedar board with a smooth surface of mm, apply it to each of the two wooden boards with a brush, and after drying at room temperature for 90 minutes,
The bonding area was 20 mm x 30 mm, and pressure bonding was carried out for 10 minutes under a load of 10 kg. After being left at room temperature for 18 hours after pressure bonding, the two wooden boards bonded parallel to each other were pulled in the shear direction at a pulling speed of 50 mm/min, and the adhesive strength (Kg/CTII) was measured.

In addition, the state of failure after the test was observed, and records were made as to whether the failure occurred at the interface between the adhered surface and the adhesive surface, the adhesive failure itself, or the adherend surface. The results are shown in Table 7. As shown in Table 7, the emulsion composition of the present invention significantly improves the adhesive strength of styrene-butadiene copolymer latex, and these effects are equivalent to or greater than those of rosin ester.

Claims (1)

[Scope of Claims] 1 (A) polyisoprene rubber latex or styrene-conjugated diene copolymer rubber latex; (B) 45-85% by weight of 1,3-pentadiene units in the polymer chain;
10-45% by weight of α-methylstyrene units, 3-20% by weight of cyclopentene units and 0% by weight of 1,3-butadiene units.
- At least one selected from hydrocarbon resins containing 20% by weight, adducts of said hydrocarbon resins with ethylenically unsaturated carboxylic acids or anhydrides thereof, or derivatives of said adducts, has a softening point of 50-170°C. 1. A novel emulsion composition comprising a resin having a solid content of 5 to 250 parts by weight per 100 parts by weight of rubber. 2. The emulsion composition according to claim 1, wherein the polyisoprene rubber latex is natural rubber latex. 3. The emulsion composition according to claim 1, wherein the styrene-conjugated diene copolymer rubber latex is a styrene-butadiene copolymer rubber latex. 4. The emulsion composition according to claim 1, wherein the adduct of the hydrocarbon resin and ethylenically unsaturated carboxylic acid or its anhydride has a saponification value of 200 or less. 5 Ethylenically unsaturated carboxylic acid having 8 or less carbon atoms.
The emulsion composition according to claim 4, which is a Teils-Alder adduct of a β-unsaturated carboxylic acid or a conjugated diene. 6 Claim 4 in which the derivative of the adduct is an ester, amide, alkali metal salt or alkaline earth metal salt
The emulsion composition described in . 7. The emulsion composition according to claim 1, which is formulated in the form of an emulsion obtained by emulsifying the resin in the presence of an emulsifier. 8 The amount of emulsifier used is 0.5 to 100 parts by weight of resin.
The emulsion composition according to claim 7, wherein the amount is 10 parts by weight. 9. The emulsion composition according to claim 7, wherein the emulsifier is an anionic emulsifier. 10. The emulsion composition according to claim 9, wherein the anionic emulsifier is a rosin acid soap. 11. The emulsion composition according to claim 7, wherein the emulsifier is a nonionic emulsifier with an HLB of 13 to 19. 12. The emulsion composition according to claim 1, which is suitable for adhesives and has a compounding ratio of rubber latex and resin in a solid content weight ratio of 5 parts by weight or more and less than 50 parts by weight per 100 parts by weight of rubber. 13. The emulsion composition according to claim 1, which is suitable as a pressure-sensitive adhesive in which the blending ratio of rubber latex and resin is 50 to 250 parts by weight per 100 parts by weight of rubber in terms of solid content weight ratio.