JPS6142746B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention provides 2,3-dichlorobutadiene-1,3
A non-crosslinked copolymer containing a soluble 2,3-dichlorobutadiene-1,3/chloroprene copolymer which has a melting point within a specific range due to the chain block structure and has a specific molecular weight range. The present invention relates to adhesive or crosslinkable compositions. The present inventors have discovered that 2,3-dichlorobutadiene-
As a result of detailed studies on the copolymer of 1,3 and chloroprene, we found that a copolymer in which the weight composition and average molecular weight of the monomer units constituting the copolymer are within a specific range is (1 ) Maintains hot melt properties and exhibits excellent flow characteristics. (2) Easily vulcanizes polychloroprene in the presence of a common vulcanization accelerator, giving a vulcanizate with improved rubber elasticity. (3) Extremely strong films can be formed in either the unvulcanized or vulcanized state. (4) Polychloroprene is soluble in common solvents. We discovered that the copolymer has characteristics in terms of processability, reactivity, and performance, and also confirmed that the copolymer is a unique polymer having a chain block of 2,3-dichlorobutadiene-1,3. As a result, the present invention was completed after realizing that it is possible to provide a composition that is extremely useful for a wide range of applications. In the present invention, the following 2,3-dichlorobutadiene-
The copolymer containing one or three chain blocks is called a block copolymer. The object of the present invention is to create a so-called hot-melt polymer that is solid at room temperature due to its crystallinity, but melts when heated and has sufficient fluidity, is soluble in common solvents for polychloroprene, and is easily vulcanized. A composition comprising a novel block copolymer capable of forming a vulcanizate with improved rubber elasticity and a strong film in either the unvulcanized or vulcanized state. It's on offer. More specifically, the object is to produce a hot-melt film-type or sheet-type adhesive, a hot-melt stretched film, characterized in that the block copolymer is blended with a hydrogen chloride scavenger and/or a vulcanization accelerator. (heat shrinkability), elastic vulcanized films, solvent-based adhesives, high hardness molded products, flame retardant due to high chlorine content, flame retardant compositions, etc. It is in. The object of the present invention is to achieve a polymer in which the weight composition ratio of the monomer units constituting the polymer is 2,3-dichlorobutadiene-
1,3/chloroprene = within the range of 60/40 to 90/10 and at the same time its number average molecular weight is 10,000 to 500,000
It has become clear that this can be achieved by a composition comprising a copolymer characterized in that it falls within the range of 1, and a hydrogen chloride scavenger and/or a vulcanization accelerator. When the number average molecular weight of the copolymer is less than 10,000, 2,3-dichlorobutadiene-1,
If the amount of 3 is not 65% or more, the crystallinity of the copolymer tends to be markedly reduced and the hot-melt properties tend to be lost, and when a film is formed, it is difficult to obtain a strong film. On the other hand, if the average molecular weight is too high, the hot melt properties of the polymer
The fluidity properties etc. deteriorate significantly and processing becomes difficult.
It is necessary to have an average molecular weight of 500,000 or less. However, the average molecular weight is about 20,000 to about
Copolymers in the range of 200,000 have hot melt properties,
It can be said that it is particularly preferable in terms of the balance between processability and performance, such as solubility and mechanical strength of the film. In addition, 2,3 of the monomer units constituting the copolymer
The weight ratio of -dichlorobutadiene-1,3/chloroprene is limited to a range of 60/40 to 90/10. When this weight ratio is smaller than 60/40, that is, when the number of chloroprene monomer units in the copolymer increases, the room temperature crystallinity of the copolymer decreases significantly;
Since the chain block of 3-dichlorobutadiene-1,3 disappears, the hot-melt property is lost and the mechanical strength of the unvulcanized product tends to decrease significantly. On the other hand, if the weight ratio is greater than 90/10,
Since it is close to a homopolymer of 2,3-dichlorobutadiene-1,3, it is crystalline at room temperature, but its melting point is high and its workability is reduced, and it is usually extremely difficult to dissolve in organic solvents. The reason why the composition ratio of the copolymer used in the present invention is limited to the above range is that it has the above-mentioned features (1) to (4) which cannot be achieved simultaneously with each homopolymer of 2,3-dichlorobutadiene-1,3 or chloroprene. ). The composition ratio of 2,3-
Dichlorobutadiene-1,3/chloroprene=
It can be said that the range of 65/35 to 80/20 is particularly preferable.
Even if the composition ratio is within this range, as the molecular weight of the copolymer increases, its toluene solubility at room temperature tends to decrease, but dissolution becomes easier when heated to 50° C. or higher. Further, as the composition ratio becomes larger than 80/20, the solubility of the copolymer in toluene at room temperature tends to decrease. The copolymer used in the present invention can be easily produced by copolymerizing 2,3-dichlorobutadiene-1,3 and chloroprene using a well-known polymerization method such as bulk polymerization or emulsion polymerization. However, solution polymerization or emulsion polymerization systems are particularly preferred as industrial production methods. However, when producing the copolymer using an emulsion polymerization system, which is easier to produce a high molecular weight than a solution polymerization system, it is practically necessary to select a polymerization recipe that is controlled in the presence of a relatively high level of molecular weight regulator. becomes. The reason why the copolymer referred to in the present invention exhibits hot-melt properties, that is, relatively sharp thermal melting behavior, is due to the presence of 2,3-dichlorobutadiene-1,3 in the copolymer.
Thermal behavior results obtained using a differential scanning calorimeter (hereinafter abbreviated as DSC) and the composition ratio of 2,3-dichlorobutadiene-1,3 monomer in the copolymer show that it is based on a chain block of This became clear from the correlation between 2,3-dichlorobutadiene-1,3/
2 if the weight composition ratio of chloroprene is less than 50/50;
Since there is virtually no crystal structure based on the contribution of chain blocks of 3-dichlorobutadiene-1,3, it has no melting point and therefore exhibits hot-melt properties, but when the ratio is 60/40 or more, 2,3-dichlorobutadiene A relatively sharp melting phenomenon is accompanied by the contribution of the butadiene-1,3 chain block.
The apparent melting point of the copolymer is naturally affected by the regularity, length, etc. of the chain blocks, but in the case of the copolymer used in the present invention, it is in the range of 80°C to 130°C, and in particular, the number average molecular weight 10,000 to 200,000, 2,3-
A copolymer having a dichlorobutadiene-1,3/chloroprene weight composition ratio in the range of 60/40 to 80/20 has a melting point in the range of about 80 to 110°C, and exhibits excellent hot-melt properties and flow properties. Since the hot-melt properties of the copolymer used in the present invention are due to the chain block of 2,3-dichlorobutadiene-1,3, the amount of the third component monomer unit that does not substantially disturb the block properties is limited. Naturally, the present invention also includes compositions using block copolymers containing the above-mentioned block copolymers. Examples of third component monomers that can actually be used include styrene, acrylonitrile,
Acrylic acid, methacrylic acid, vinyl compounds such as vinyl pyridine, isoprene, butadiene-1,
Examples include, but are not limited to, conjugated dienes such as No. 3. These monomer units are 2,3-dichlorobutadiene-1,3 in the copolymer.
In order not to substantially disturb the chain block of the polymer, it is desirable that the weight composition of the monomer unit is usually 5% or less of the total polymerized weight. The hydrogen chloride scavenger used in the composition of the present invention may be any one that can capture hydrogen chloride generated when the copolymer is cold or heated, such as zinc white, magnesia, Metal oxides or metal hydroxides such as litharge, red lead, barium oxide, zinc hydroxide, magnesium hydroxide, metal carbonates such as calcium carbonate, barium carbonate, zinc carbonate, organic compounds such as potassium stearate, barium stearate. acid salts, epoxidized soybean oil, epoxidized butyl stearate, bisphenol A-type epoxy resins, epoxy group-containing compounds such as styrene oxide, phenyl group-substituted carbinols such as anis alcohol, benzyl alcohol, and triphenyl carbinol. tertiary alcohols such as t-amyl alcohol, t-dodecyl alcohol, etc.
alcohols, tetraethylenepentamine, N
Typical examples include amines such as -aminoethylpiperazine and tri(dimethylaminomethyl)phenol. However, it is not limited to these. The hydrogen chloride scavenger acts as a stabilizer against dehydrochlorination of the block copolymer used in the present invention, and is effective in improving the storage stability of the composition of the present invention or preventing performance deterioration and discoloration due to deterioration. In particular, when it is desired to heat-vulcanize the blocking copolymer to obtain a composition suitable for practical use, the effectiveness of the above-mentioned scavenger is important because dehydrochlorination from the copolymer during heat-vulcanization is unavoidable. becomes noticeable. Some of these scavengers act only as scavengers for hydrogen chloride, while others, such as metal hydroxides and amines, also act as vulcanization accelerators for the copolymer. Any of them can be used depending on the purpose of the composition of the present invention. The amount of these hydrogen chloride scavengers used varies somewhat depending on the type and purpose of use, but is usually about 1 to 30 parts by weight, particularly preferably about 2 to 10 parts by weight, per 100 parts by weight of the copolymer. Further, when the composition of the present invention is used as a vulcanizate, a vulcanization accelerator for the copolymer can be used. Typical examples of these vulcanization accelerators include the metal oxides, metal hydroxides, and amines mentioned above, as well as known vulcanization accelerators for chloroprene rubber such as ethylenethiourea and o-tolylguanidine. Both can be used. The amount of the vulcanization accelerator used varies considerably depending on the type of the vulcanization accelerator, and is usually in the range of 0.1 to 30 parts by weight per 100 parts by weight of the copolymer. These vulcanization accelerators may be used alone or in combination of two or more. The characteristics of the composition according to the present invention are attributable to the properties of the block copolymer; for example, films or molded products with excellent hot melt properties are produced by
Its mechanical strength is excellent even in an unvulcanized state due to the cohesive force contributed by the dichlorobutadiene-1,3 chain block. Compositions obtained by vulcanizing these materials tend to lose their hot-melt properties, but their mechanical strength, solvent resistance, and high-temperature adhesive strength become even better. Compositions according to the invention therefore include, but are not limited to, the embodiments described below with a wide variety of non-crosslinkable compositions. (1) Hot melt type compositions: adhesives, adhesives, sealants, lining materials,
Coating agents, wrapping films, molded products (2) Solvent type compositions: adhesives, primers, paints, lining materials,
Sealing material, casting film (3) Fire and flame retardant composition for use in (1) and (2) above,
(This is because the chlorine content of the copolymer is as high as 50 to 55% by weight.) In addition, if necessary for practical use in the above-mentioned applications, fillers such as titanium white, silica, clay, and carbon black, which are common compound components, may be used. Softeners such as agents, petroleum oils, phthalate esters, and tar,
Resins such as phenol resin, coumaron indelesin, petroleum-based aromatic resin, rosin acid ester resin, bituminous materials such as straight asphalt, blown asphalt, and tar pitch, antioxidants such as hindered phenol, aromatic amine, and coloring. additives, glass, alumina, steel,
It is possible to blend inorganic or organic fibers made of carbon or the like. Examples and comparative examples are shown below. Parts and percentages herein are based on weight unless otherwise specified. The copolymers used here were produced according to the following polymerization recipe and isolation method, and are summarized in Table 1.

[Table] Copolymer isolation method After treating the polymerization solution with a thin film evaporator under reduced pressure to remove unreacted monomers, excess methanol was added to precipitate the polymer, and then the roll surface temperature was 110°C to 120°C.
It was dried in a melted state in a drum dryer at .degree. C., and then cooled to room temperature to isolate it in the form of a solid sheet. (Note) For footnotes 1 to 4, refer to (note) in Table 1.

[Table] Example 1 Using the copolymers shown in Table 1, various films were prepared from formulations according to the following formulations, and their physical properties were measured. The film was produced as follows. (1) Continuously apply the polymer or its blend in a molten state onto release paper using a roll coater with an unvulcanized film surface temperature of 110 to 120°C, and cool to room temperature to form a film with a thickness in the range of 100 to 300 microns. I got the film. (2) Vulcanized film The mixture is kneaded in a molten state on a paint roll with a surface temperature of 110 to 120°C, and then press-vulcanized between ferro plates. The test results are shown in Table 2. Here is test No. 6,
7 is a comparative example in which a copolymer not according to the present invention was used. As is clear from these results, it is clear that any composition according to the present invention can form a strong film.

[Table] Example 2 A compound obtained using copolymer No. 2 listed in Table 1 according to the formulation shown below was treated in the same manner as in Example 1 to produce a vulcanized film, and its physical properties were measured. The results are shown in Table 3. Test Nos. 12 and 13 are comparative examples not based on the present invention.

[Table] Example 3 Using the 200 micron thick unwashed film obtained in Test No. 3 of Example 1, a test was conducted as a hot melt type adhesive, as shown in Table 4. , it was recognized that it had excellent adhesive strength.

[Table] Example 4 100 parts of copolymer No. 4 listed in Table 1 and 5 parts of zinc white
A compound containing 4 parts of magnesia and 1 part of ethylene thiourea was heat-melted at 150°C, then cast into a complex mold, maintained at this temperature for 1 hour, and then cured. When this was then cooled to room temperature and taken out from the mold, an elastic product with high hardness (JIS hardness 97) with excellent mold followability was obtained. Example 5 The same compound used in Example 4 was used.
The liquid heated at 150°C was lined with a thickness of about 1 mm on a steel plate preheated to 110°C, and then aged in a gear oven at 100°C for 48 hours and then vulcanized. This lining layer exhibited excellent solvent resistance, with a polymerization change of only 48% after being immersed in toluene at 25°C for 4 days. In addition, the physical properties of the lining layer are tensile strength of 240Kg/
^cm2 , elongation 63%, hardness (JIS) 95, water resistance,
It also had excellent chemical resistance. Example 6 100 parts of copolymer No. 3 listed in Table 1 had a softening point of 60
~80℃ 50 parts of coumaron indene resin, 5 parts of zinc white
1 part, 4 parts of magnesia and 2 parts of trimethylthiourea
The resulting compound was melt-kneaded on rolls with a surface temperature of 110°C and dissolved and dispersed in toluene to form a solution with a total solid content of 50%. This solution is
The Bruckfield viscosity at 25°C was 420 centipoise, and it had excellent workability as an adhesive, primer, or paint base. Example 7 100 parts of copolymer No. 1 listed in Table 1 and 10 parts of zinc white
The flame retardancy of the compound obtained by melting and kneading 200 parts of soft clay, and 1 part of trimethylthiourea in the same manner as in Example 6 was evaluated using the vertical combustion method according to the UL-94 standard. There was nothing at all.

Claims (1)

[Scope of Claims] 1 2,3-dichlorobutadiene-1,3 and chloroprene containing a chain block structure of 2,3-dichlorobutadiene-1,3 and satisfying the following conditions (1) to (3) A non-crosslinkable or crosslinkable block copolymer composition having hot melt properties, comprising a block copolymer with a hydrogen chloride scavenger and/or a vulcanization accelerator. . (1) Melting point measured by differential scanning calorimeter is 80~
130℃ (2) Number average molecular weight is 10,000 to 500,000 (3) Weight composition ratio of monomer units constituting the copolymer: 2,3-dichlorobutadiene-1,3/chloroprene = 60/40 to 90/10