JPH0768456B2 - Polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polymer composition, and in particular, provides a sealant having good compatibility with a plasticizer and having a small amount of the plasticizer used. At the same time, it relates to a polymer composition as a curing agent for an epoxy resin, which gives a cured product having a high curing speed and good durability.

[Conventional technology]

A polymer containing two or more thiol groups in one molecule is easily cured when mixed with an oxidizing agent, and the thiol group also easily reacts with epoxy groups, isocyanate groups, etc. to increase the molecular weight. Widely used in materials, paints, adhesives, etc.

Among these thiol group-containing polymers, US Pat.
The polysulfide polymer described in Japanese Patent No. 466,963 has been used for many years as a raw material for a sealing material because it has excellent oil resistance, chemical resistance, flexibility and the like. In addition, the above polysulfide polymer can impart flexibility to an epoxy resin by using it together with an epoxy resin containing two or more epoxy groups in one molecule.

[Problems to be Solved by the Invention]

Polysulfide polymers in the molecule -S _x - _(x = 1
Although it is a unique polymer containing the structures (1) to (5), only a limited number of plasticizers can be used because of its high polarity. That is,
Since a general-purpose inexpensive plasticizer cannot be used, the cost becomes high when it is used as a compound such as a sealing material. Further, since the viscosity is higher than the molecular weight of the polymer, it is necessary to add a large amount of plasticizer in order to improve the workability of the compound.
Therefore, when a coating material is applied to a cured product of a sealing material made of polysulfide polymer, there is a problem that the coating film is softened by the oozing out of the plasticizer.

Further, when used together with an epoxy resin, the adhesive strength and the water resistant adhesiveness are good, but there is a problem that the curing at a low temperature is slow.

On the other hand, the thiol group-containing polyether polymer described in Japanese Examined Patent Publication No. 47-48279 has a problem that it has poor water-resistant adhesiveness, although it has fast curability at low temperatures.

Therefore, the object of the present invention is to improve the compatibility between the liquid polysulfide polymer and the plasticizer, and by reducing the amount used, a polymer composition in which the coating film does not soften even when the coating material is applied to the cured product. It is to provide things.

Another object of the present invention is to have flexibility, which is an advantage of polysulfide when used together with an epoxy resin,
It is an object of the present invention to provide a polymer composition which has sufficient adhesive strength, water resistance, and has a high curing rate.

[Means for Solving the Problems]

As a result of earnest research in view of the above object, the inventors of the present invention mixed a thiol group-containing polyether polymer containing a disulfide bond in the main chain with a polysulfide polymer, so that the polysulfide polymer alone was not compatible. Since the agents become compatible with each other and the polymer viscosity after mixing decreases, the amount of plasticizer used can be reduced, and when paint is applied to the cured product, migration of plasticizer to the coating film is reduced. However, it has been found that the stain resistance is improved. It has also been found that when used together with an epoxy resin, it cures quickly at low temperatures and has sufficient adhesive strength and water resistance. The present invention has been completed based on these findings.

That is, the polymer composition of the present invention comprises: (a) a polysulfide polymer; and (b)-(R ₁ O) _{n in the} main chain, provided that R ₁ has 2 to 4 carbon atoms.
And an n is an integer of 6 to 200. ) And a thiol group-containing polyether polymer containing a disulfide bond and having a thiol group at the terminal and having a sulfur content / thiol group content ratio of 1.06 or more in the polymer (a) / (b) = 95. It is characterized by being mixed in a weight ratio of / 5 to 5/95.

Hereinafter, the present invention will be described in detail.

The polysulfide polymer in the composition of the present invention is
It is represented by the following general formula (1).

HS (R ₂ S _x ) _m R ₂ SH (1) In the above general formula, x is an integer of 1 to 5, and its average value is 2. m is an integer of 1 to 50.

Further, R ₂ is _{-CH 2 CH 2 -, - C} 2 H 4 OC 2 H 4 -, - C 2 H 4 OCH 2 OC 2
Organic residues such as H ₄ −, −C ₄ H ₈ OC ₄ H ₈ − and the like.

The polysulfide polymer of the present invention has fluidity at room temperature and has a molecular weight of 100 to 200,000, preferably 400 to 50,000.
Is.

Preferred examples of such polysulfide polymers are described in US Pat. No. 2,466,963.

The thiol group-containing polyether polymer (b) in the present invention has-(R ₁ O) _n as a polyether moiety in the main chain.
-Including. Here, R ₁ is an alkylene group having 2 to 4 carbon atoms, n
Indicates an integer of 6 to 200. The molecular weight of this polyether moiety is preferably 400 to 10,000. If the molecular weight is less than 400, the effect of improving the compatibility with the plasticizer when mixed with the polysulfide polymer is small, and if it exceeds 10,000, the viscosity of the polymer increases, which is not preferable.

Further, this thiol group-containing polyether polymer has a disulfide bond in the main chain and has a thiol group at the terminal, and the weight ratio of sulfur content / thiol group content in the polymer is 1.06 or more. When the ratio of sulfur content / thiol group content is less than 1.06, the proportion of disulfide bonds is small,
Poor compatibility with polysulfide polymer.

Preferred examples of such a thiol group-containing polyether polymer include those synthesized by the known method described in JP-B-47-48279. That is, after adding epihalohydrin such as epichlorohydrin or epibromohydrin to polyalkylene glycol such as polypropylene glycol or polyethylene glycol, the reaction is performed with alkali hydrosulfide such as sodium hydrosulfide or potassium hydrosulfide to give the following general formula: A polyether polymer having a functional group represented by (2) is obtained. The polymer thus obtained partially contains a disulfide bond in the main chain and is suitable as the thiol group-containing polyether polymer of the present invention.

Other known compounds include mercaptan-terminated liquid polymers having a structure represented by the following general formula (3) described in U.S. Pat. No. 3,923,748, which is obtained by oxidizing a part of thiol group with an oxidizing agent. Introducing a bond, polymercaptan having a structure represented by the following general formula (4) described in U.S. Pat. No. 4,092,293 and Japanese Patent Publication No. 46-3389, and a part of the thiol group is similarly treated with an oxidizing agent. Examples thereof include those that are oxidized to introduce a disulfide bond.

(However, R ₃ is hydrogen or a methyl group, and p, q, and r are 6
Is an integer from ~ 200. ) The mixing ratio of the polysulfide polymer (a) of the present invention and the thiol group-containing polyether polymer (b) is 95/5 to 5/95 by weight. If the polysulfide polymer content is less than 5% by weight, the weather resistance of the cured product will be poor. Further, if the amount of the thiol group-containing polyether polymer is less than 5% by weight, the effect of improving the compatibility with the plasticizer is small.

In the present invention, a polymer composition comprising the above polysulfide polymer and a thiol group-containing polyether polymer is easily cured at room temperature by mixing an oxidizing agent, and is suitable for a sealing material, an adhesive, etc. be able to.

As the oxidizing agent in the composition of the present invention, substances that have been conventionally used as curing agents for thiol group-containing polymers can be used. Specific examples of these oxidizing agents include ZnO ₂ and Fe.
_{O 2, PbO 2, MgO 2} , CaO 2, BaO 2, MnO 2, TeO 2, SeO 2, Pb 3 O
₄ , inorganic peroxides such as SrO ₂ and LiO ₂ , ZnO, FeO, PbO, Fe ₂ O
₃ , Sb ₂ O ₃ , inorganic oxides such as MgO, CoO, CaO, CuO, BaO, N
a ₂ CrO ₄ , K ₂ CrO ₄ , Na ₂ Cr ₂ O ₇ , K ₂ Cr ₂ O ₇ , NaClO ₄ , NaBO ₂
H ₂ O ₂ , K ₂ C ₂ O ₆ , KMnO ₄ , sodium percarbonate (2Na ₂ CO ₃ + 3H
₂ O ₂ ) and other inorganic oxidants, benzoyl peroxide, dicumyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butyl perbenzoate, sodium peracetic acid, organic peroxides such as urea peroxide , Organic oxidants such as nitrobenzene, dinitrobenzene, and paraquinone dioxime are mentioned, but PbO ₂ is most widely used. In the composition of the present invention, the blending amount of these oxidizing agents varies depending on the type of the oxidizing agent, but generally 1 to 50 parts by weight with respect to 100 parts by weight of the mixture of the polysulfide polymer and the thiol group-containing polyether polymer. It is preferably part by weight.

In the polymer composition of the present invention, further economy, for the purpose of improving the workability when applying the composition and the physical properties after curing,
Fillers such as calcium carbonate, talc, clay, titanium oxide, silica and the like can be added. Further, the polymer composition of the present invention is compatible with inexpensive phthalate esters such as dioctyl phthalate (DOP) and diheptyl phthalate (DHP), which could not be used in the case of only polysulfide polymer, It is possible to add these. Plasticizers such as chlorinated paraffin and hydrogenated terphenyl can also be added. Incidentally, the polymer composition comprising a polysulfide polymer and a thiol group-containing polyether polymer according to the present invention has a low viscosity as compared with the case of only the polysulfide polymer, and therefore the addition amount of the plasticizer is 40 parts by weight with respect to 100 parts by weight of the polymer. Below the section,
Sufficient workability can be obtained.

Further, by blending an epoxy resin containing two or more epoxy groups in one molecule and an amine into a polymer composition comprising a polysulfide polymer according to the present invention and a thiol group-containing polyether polymer, only a polysulfide polymer is prepared. As compared with the case where the thiol-containing polyether polymer alone is used, curing at a low temperature is faster, and a cured product having flexibility and sufficient water-resistant adhesiveness can be obtained.

Examples of the epoxy resin used in the present invention include bisphenol A, halogenated bisphenol A, bisphenol F, halogenated bisphenol F, resorcinol, hydroquinone, pyrocatechol, 4,4′-dihydroxybiphenyl and 1,5-hydroxynaphthalene. Epoxy resin obtained by adding epichlorohydrin to polyhydric phenol, epoxy resin obtained by adding epichlorohydrin to polyhydric alcohol such as ethylene glycol, propylene glycol and glycerin, and oxybenzoic acid, phthalic acid Examples thereof include epoxy resins obtained by adding epichlorohydrin to aromatic dicarboxylic acids.

The amines used in the present invention are preferably those used as a curing accelerator when a thiol group-containing polymer is used as a curing agent in an epoxy resin. Specifically, N, N−
Aliphatic tertiary amines such as dimethylpropylamine, N, N, N ', N'-tetramethylhexamethylenediamine, N
-Alicyclic tertiary amines such as methylpiperidine and N, N'-dimethylpiperazine, aromatic tertiary amines such as benzyldimethylamine, dimethylaminomethylphenol, and 2,4,6-tris (dimethylaminomethyl) phenol And the like.

[Work]

When mixed with an oxidizing agent, the polysulfide polymer is easily cured at room temperature to give a cured product having oil resistance, chemical resistance, and excellent flexibility. However, due to the high polarity of the polymers, only limited plasticizers can be used. Therefore, the main chain - (R ₁ O) _n - a, and comprises a disulfide bond, and ends having a thiol group, moreover, such as the weight ratio of sulfur content / thiol group content in the polymer is 1.06 or more By using a composition in which the thiol group-containing polyether polymer is mixed at a ratio of polysulfide polymer / thiol group-containing polyether polymer = 95/5 to 5/95, the polarity of the polymer is lowered and the viscosity is also lowered. Therefore, inexpensive phthalate esters such as dioctyl phthalate (DOP) and diheptyl phthalate (DHP), which were not compatible only with the polysulfide polymer, are compatible with each other. Furthermore, since the viscosity of the polymer is low, the amount of plasticizer used can be small.

Further, by mixing a polysulfide polymer and a thiol group-containing polyether polymer, when used together with an epoxy resin and amines, curing at low temperature is fast,
A cured product having sufficient water resistant adhesion is obtained. this is,
In the case of only polysulfide polymer, the water-resistant adhesion is good, but the curability at low temperature is insufficient, while in the case of only the thiol group-containing polyether polymer, the curability at low temperature is fast but the water-resistant adhesion is insufficient. However, by mixing two kinds of polymers having such characteristics, their respective defects are covered and a composition having the advantages of both is obtained.

〔Example〕

 The invention will be explained in more detail by the following examples.

Synthesis Example 1 Bifunctional polypropylene glycol obtained by adding propylene oxide to propylene glycol (OH number 16
2) 1000 g, 294.4 g of epichlorohydrin and 2.0 g of stannic chloride pentahydrate were charged into the reaction vessel of 2 and stirred at 100 ° C. for 3 hours. In addition, 254.6 g of sodium hydrosulfide (purity
70%) was added and the mixture was stirred at 100 ° C. for 1.5 hours. Then, the salt was removed to obtain a pale yellow transparent liquid polymer. The polymer obtained had a sulfur content of 7.0% and a thiol group content of 5.7%.

Synthesis Example 2 Bifunctional polypropylene glycol obtained by adding propylene oxide to propylene glycol (OH value: 11
2) 1000 g, 203.5 g of epichlorohydrin, and 2.0 g of stannic chloride pentahydrate were charged into the reaction vessel of 2 and stirred at 100 ° C. for 3 hours. In addition, 176.0 g of sodium hydrosulfide (purity
70%) was added and the mixture was stirred at 100 ° C. for 1.5 hours. Then, the salt was removed to obtain a pale yellow transparent liquid polymer. The polymer obtained has a sulfur content of 5.0% and a mercaptan content of 3.8%.
Met.

Synthesis Example 3 1000 g of trifunctional polypropylene glycol (OH value 394) obtained by adding propylene oxide to glycerin
Then, 715.9 g of epichlorohydrin and 2.0 g of stannic chloride pentahydrate were charged into the reaction vessel of 2, and stirred at 100 ° C. for 3 hours. Further, 619.1 g of sodium hydrosulfide (purity 70%) was added, and the mixture was stirred at 100 ° C for 1.5 hours. Then, the salt was removed to obtain a pale yellow transparent liquid polymer. The obtained polymer had a sulfur content of 12% and a mercaptan content of 9.5%.

Example 1 and Comparative Example 1 The polymer obtained in Synthesis Example 1 and a polysulfide polymer (manufactured by Toray Thiokol Ltd., trade name “Thiocol LP5”)
5 ") in a weight ratio of 1/1 to give a mercaptan content of 3.5%,
A brown transparent polymer having a viscosity of 60 poise (25 ° C.) was obtained.

100 parts by weight of the obtained polymer and 16 parts by weight of PbO ₂ were mixed, poured into a mold having a thickness of 2 mm, and aged at 20 ° C. for 20 hours to obtain a sheet-shaped cured product. About this sheet cured product
A tensile test (pulling speed: 500 mm / min) was performed according to the TM D 638-84 TYPE IV standard, and the breaking strength was 5.7 kg / c.
m ² , elongation 500% was obtained. Further, when the A hardness was measured according to JIS K 6301, a hardness of 20 was obtained.

Further, the obtained polymer and various plasticizers shown in Table 1 were mixed at a weight ratio of 10/5 and compatibility was examined.

The results are shown in Table 1.

As Comparative Example 1, the compatibility of a polysulfide polymer (trade name “Thiocol LP55” manufactured by Toray Thiokol Co., Ltd.) and a plasticizer mixed at a weight ratio of 10/5 was also the first.
Shown according to the table.

Example 2 The polymer obtained in Synthesis Example 2 and a polysulfide polymer (manufactured by Toray Thiokol Ltd., trade name “Thiocol LP5”)
5 ") was mixed in a weight ratio of 7/3 to obtain a brown transparent polymer having a thiol group content of 2.4% and a viscosity of 120 poise (25 ° C). 100 parts by weight of the obtained polymer and 11 parts by weight of PbO ₂ Was mixed and poured into a mold having a thickness of 2 mm, and cured at 20 ° C. for 20 hours to obtain a sheet-shaped cured product.
A tensile test (pulling speed: 500 mm / min) was conducted according to the standard of TM D 638-84 TYPE IV, and the breaking strength was 4.0 kg / cm ^2.
I got an elongation of 400%. Further, when the A hardness was measured according to JIS K 6301, a hardness of 14 was obtained.

Example 3 and Comparative Example 2 The polymer of Example 1 was blended with a plasticizer and a filler in the proportions shown in Table 2 to obtain a main agent. On the other hand, PbO ₂ (oxidizer) and plasticizer,
A curing agent was obtained by blending with a vulcanization aid in a ratio shown in Table 3.

This mixture was subjected to an extrudability test at 5 ° C according to JIS A-5758. Further, using an aluminum plate as an adherend, after aging at 20 ° C. for 7 days, it was further cured at 50 ° C. for 7 days, and a tensile adhesion test was conducted according to JIS A-5758. The use of a polysulfide polymer "Thiokol LP55" in the polymer as Comparative Example 2, using the butyl benzyl phthalate plasticizer, were subjected to the same tests oxidizing agent (PbO ₂₎ as 7.5 parts by weight.

Further, the main agent and the curing agent were mixed and poured into a mold having a thickness of 5 mm to obtain a sheet-shaped cured product. This cured product in sheet form
After curing for 7 days at ℃, paint containing vinyl chloride resin as the main component (Kinsai Paint Co., Ltd. “Vinibon”), polyacrylic acid ester as the main component (Kansai Paint Co., Ltd. “Vini Deluxe” "," Hedyne "manufactured by Daido Paint Co., Ltd.) was applied, and the state of each coating film was observed after 14 days at 20 ° C. Further, the same test was performed on the main agent and the curing agent of Comparative Example 2.

The results are shown in Table 4.

Example 4 The polymer obtained in Synthesis Example 3 and a polysulfide polymer (trade name “Thiocol LP3” manufactured by Toray Thiokol Co., Ltd.)
When and were mixed at a weight ratio of 3/1, the thiol group content was 9.0
%, A viscosity of 112 poise (25 ° C.) was obtained, which was a brown transparent polymer composition.

Examples 5 and Comparative Examples 3 and 4 80 parts by weight of the polymer composition of Example 4 and 100 parts by weight of a bisphenol A type epoxy resin (trade name "EP-4100" manufactured by Asahi Denka Co., Ltd.), and Add 10 parts by weight of 2,4,6-tris (dimethylaminomethyl) phenol,
The above mixture was sandwiched between cold-rolled steel plates (1.6 mm x 25 mm x 100 mm) and aged at 20 ° C for 14 days, and after aged at 20 ° C for 7 days, further immersed in water (20 ° C) for 7 days. Tensile-shear adhesive strength was measured about each thing. The formulation was also mixed on a 20 g scale and the cure rate at 20 ° C. was measured. The time when the fluidity disappeared was recorded as the gel time, and the time when the tack disappeared was recorded as the tack free time as a guide for curing.

On the other hand, instead of the polymer composition of Example 4, a polysulfide polymer (using a trade name "Thiocol LP3" manufactured by Toray Thiokol Co., Ltd.) was used as Comparative Example 3, and a commercially available thiol group-containing polyether polymer (oiled shell Comparative Example 4 was prepared by using only Epoxy Co., Ltd., trade name “Cup Cure 3-800LC”, and the same composition as in Example 5 was used, and the tensile shear adhesive strength and the curing rate were measured.

The results are shown in Table 5.

[Effect of the Invention] The polymer composition of the present invention is compatible with inexpensive phthalate esters such as dioctyl phthalate (DOP) and diheptyl phthalate (DHP), which were not compatible with the polysulfide polymer alone. In addition, since the viscosity of the polymer is low, the amount of plasticizer used can be reduced. Furthermore, when a coating material is applied to the surface of a cured product that has been cured with an oxidizing agent, there is little softening of the coating film due to migration of the plasticizer. When used together with an epoxy resin and amines, it gives a cured product that cures quickly at low temperatures and has sufficient water resistant adhesion. Such a polymer composition is suitable for use as a sealing material, a potting material, an adhesive or the like.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-59-18757 (JP, A) JP-A-62-273253 (JP, A) JP-A-55-137127 (JP, A) JP-A-62- 53355 (JP, A) JP 63-22858 (JP, A) JP 56-109275 (JP, A) JP 58-47078 (JP, A) JP 52-128948 (JP, A)

Claims (3)

[Claims] 1. A (a) polysulfide polymer, and (b) in the main chain _{- (R 1 O) n -} ( where, R ₁ is 2 carbon atoms
4 is an alkylene group, and n is an integer of 6 to 200. ), And a thiol group-containing polyether polymer containing a disulfide bond and having a thiol group at the terminal and having a sulfur content / thiol group content ratio of 1.06 or more in the polymer, (a) / (b) = 95/5 to 5/95 in a weight ratio of the polymer composition. 2. The polymer composition according to claim 1, further comprising (a) a polysulfide polymer, (b) a thiol group-containing polyether polymer, and an oxidizing agent. Combined composition. 3. The polymer composition according to claim 1, wherein the (a) polysulfide polymer, the (b) thiol group-containing polyether polymer, and an epoxy containing two or more epoxy groups in the molecule. A polymer composition comprising a resin and an amine.