JPS5815779B2 - Hikari Kasei Oyuusuru Hensei Polybutadiene Seibutsu - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a modified polybutadiene composition having photocurability suitable for forming a relief for a printing plate by irradiation with light.

In particular, this invention is transparent, which is soluble in polar solvents such as acetone, methyl ethyl ketone, and basic aqueous solutions before curing, but becomes a photocured product that is insoluble in polar solvents and basic aqueous solutions when cured by light irradiation. The invention relates to a liquid composition, from which reliefs for letterpress printing having excellent properties can be produced.

Conventionally, photocurable liquid compositions include compositions obtained from unsaturated polyesters, compositions obtained from 1,2-polybutadiene oligomers, and reaction products of epoxidized polybutadiene and unsaturated carboxylic acids. Compositions obtained from unsaturated polyester are known, but photocured products obtained from unsaturated polyester are highly hygroscopic and become moist when left in the air for a long time, resulting in a decrease in hardness. However, the composition obtained from the 1,2-polybutadiene oligomer has the following disadvantages (Comparative Example 1):
The compatibility between the 2-polybutadiene oligomer and the crosslinking agent is poor, resulting in a cloudy appearance, and therefore, when attempting to photocure a thick liquid layer of the composition, such as when making a relief, the curing time becomes longer and The hardness of the photocured product also has the drawback of not being a practical value (Comparative Example 2.3), and
Although a composition obtained from a reaction product of epoxidized polybutadiene and an unsaturated carboxylic acid cures in a relatively short curing time, the hardness of the cured product is low, making it impractical.

The inventors have arrived at the present invention as a result of intensive research into photocurable resin compositions for reliefs that do not have the above-mentioned drawbacks and have excellent properties.

In other words, this invention provides liquid polybutadiene with a molecular weight of 500 to 5000, a hydroxyl group and/or a general formula -0
The total amount of ester groups represented by -COR (R is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms) is 0.2 to 0.6 per butadiene unit of the liquid polybutadiene. 100 parts by weight of modified polybutadiene bonded in a proportion of 100 parts by weight, and (1) - glycol diester represented by the general formula, (2) lucridyl ester represented by the general formula, and (3) - trimethylol represented by the general formula as crosslinking agents. 20 to 200 parts by weight of at least one compound selected from the group consisting of propane triesters (however,
In the formula, n is an integer of 1 to 4, R' and R' are a hydrogen atom or a methyl group), and as an initiator, R'' is an alkyl group having 1 to 3 carbon atoms. The present invention relates to a photocurable modified polybutadiene composition comprising 0.01 to 10 parts by weight of benzoin ether.

The photocurable modified polybutadiene composition of the present invention is a transparent, liquid composition with a diameter of 250 to 350 mμ.
It can be photocured by irradiation with light from a light source that emits light at a wavelength of and this composition is easily soluble in polar solvents such as acetone, ketones such as methyl ethyl ketone, alcohols such as methyl alcohol, ethyl alcohol, or basic aqueous solutions such as sodium hydroxide and potassium hydroxide. do.

Therefore, if we take advantage of the properties of this composition, we can place a negative film on the liquid layer of this composition, irradiate it with light from an appropriate light source, and then dissolve and remove the unhardened portion with a polar solvent or basic aqueous solution. Reliefs can be produced by this process.

The relief obtained by photocuring as described above has a high initial hardness immediately after photocuring, a low wettability after being left in an atmosphere of 100% humidity at 25°C for 20 hours, and a small decrease in hardness at that time. It has excellent properties such as good resolution when printed using relief.

The modified polybutadiene which is one component of the composition of the present invention is a liquid polybutadiene having a molecular weight of 500 to 5000, and a hydroxyl group and/or an ester group represented by the general formula -0-COR in the total amount thereof. It is a modified polybutadiene bonded at a ratio of 0.2 to 0.6 units per butadiene unit of liquid polybutadiene.

There are various methods for producing the modified polybutadiene, and any method may be used as long as it can produce a modified polybutadiene having the content of hydroxyl groups and ester groups as described above.

For example, liquid polybutadiene with a molecular weight of 500 to 5,000 and hydrogen peroxide are reacted in a suitable solvent in the presence of a carboxylic acid having 1 to 5 carbon atoms or an ester of this carboxylic acid and an alcohol having 1 to 3 carbon atoms. By doing this, it is possible to produce a modified polybutadiene in which a hydroxyl group or a hydroxyl group and an ester group are bonded.For modified polybutadiene having a hydroxyl group and an ester group, the ester group is further saponified or the hydroxyl group is esterified. Modified polybutadiene having only hydroxyl groups or ester groups can be produced by this method.

In addition, as an example of the manufacturing method when formic acid is used as the carboxylic acid used in the above manufacturing method, the US
There is a method described in the specification of P2692892.

In this invention, the liquid polybutadiene before modification of the modified polybutadiene is a liquid polybutadiene that does not have a functional group at the end, a hydroxyl group or a carboxyl group at the end,
It is a liquid polybutadiene having epoxy groups, etc., and its molecular weight is 500 to 5,000, particularly 700 to 3,500.

If a modified polybutadiene obtained from a liquid polybutadiene with a molecular weight of less than 500 is used, the initial hardness will be low and the curing time will be long when the resulting composition is photocured, so it is not suitable.
If it is higher than this, the compatibility between the modified polybutadiene obtained therefrom and the crosslinking agent decreases, and the composition becomes opaque, so that the photocuring time by light irradiation becomes longer, which is not appropriate.

In addition, the total content of hydroxyl groups and ester groups bonded to the modified polybutadiene is 0.2 to 0 per butadiene unit constituting the liquid polybutadiene before modification.
．． The ratio is 6 pieces, preferably 0.25 to 0.5 pieces.

The ratio of the hydroxyl group to the ester group ([~OH]/[-0
-COR]) is not particularly limited, but a ratio of hydroxyl group to ester group of 1 to 35 is preferred because the curing time of the composition obtained therefrom is short.

If the content ratio of the total amount of hydroxyl groups and ester groups in the modified polybutadiene is less than 0.2, the initial hardness of the photocured product of the resulting composition will be extremely low, making it impractical; If the amount exceeds 1, the compatibility of the modified polybutadiene with the crosslinking agent decreases, and the transparency of the composition decreases, which increases the curing time in photocuring of thick liquid layers such as in relief production, and increases the hardness of the polybutadiene. It is not suitable because it may lower the temperature or make the cured product brittle.

Note that the microstructure of the liquid polybutadiene before modification is not particularly limited, and any microstructure may be used.

It is preferable that the content of 1.2 structure (vinyl structure) in % is 30% or more because the hardness of the cured product increases.

In this invention, the crosslinking agent that is one component of the composition is at least one selected from the group consisting of glycidyl esters represented by the general formula and trimethylolpropane triesters represented by the general formula. It is a compound of

Examples of the glycol diester include ethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, tetraethylene glycol diacrylate, and tetraethylene glycol dimethacrylate. , propylene glycol diacrylate, propylene glycol dimethacrylate, diethylene glycol diacrylate,
Examples include dipropylene glycol dimethacrylate, tripropylene glycol diacrylate, and triethylene glycol diacrylate.

Furthermore, examples of the glycidyl esters include glycidyl acrylate and glycidyl methacrylate.

Further, examples of the trimethylolpropane triester include trimethylolpropane triacrylate and trimethylolpropane tritacrylate.

In the composition of this invention, the content of the crosslinking agent is 20 to 200 parts by weight, preferably 30 to 100 parts by weight, based on 100 parts by weight of the modified polybutadiene.

If the content of the crosslinking agent is less than the above-mentioned 20 parts by weight, the initial hardness of the cured product will be too low when the composition is photocured, so it is not suitable, and if it is more than the above-mentioned 200 parts by weight, the composition will It is not suitable because the curing time is long and the crosslinking becomes dense due to photocuring, so that only a photocured product with no flexibility can be obtained.

In this invention, the above-mentioned crosslinking agent can be blended alone, or two or more types of crosslinking agents can be blended in combination.

Furthermore, acrylic acid and/or methacrylic acid is added to the crosslinking agent in an amount of 60 parts by weight or less based on 100 parts by weight of the modified polybutadiene, and the total amount of crosslinking agent (including acrylic acid and/or methacrylic acid) 55% by weight of
If the compound is added as a crosslinking agent in an amount within the range below, a composition with high initial hardness can be obtained when the composition is photocured.

However, in this case, as the content of acrylic acid and/or methacrylic acid increases, the wettability of the photocured product decreases, and the hardness of the cured product after wetting decreases significantly, which is not preferable in terms of storage of the cured product.

Furthermore, the amide derivatives such as acrylamide, methacrylic amide, or N-butoxymethylmethacrylamide are added to the crosslinking agent, and the modified polybutadiene 1
When blended with a crosslinking agent by adding it in an amount of 60 parts by weight or less based on 00 parts by weight and 75% by weight or less of the total crosslinking agent,
The photocuring time of the resulting composition is shortened, and the hardness of the photocured product is increased.

However, if the amount of acrylamide, methacrylamide, or their derivatives added exceeds the above amount,
It is not preferable to add a large amount because the hardness of the photocured product decreases.

In this invention, one component of the composition is benzoin ether, which is the starting water.

Examples of the benzoin ether include benzoin methyl ether, benzoin ethyl ether, and benzoin propyl ether.

In the composition of this invention, the content of the initiator is 0.01 to 10 parts by weight, preferably 0.1 to 7 parts by weight, based on 100 parts by weight of the modified polybutadiene.

When the content of the initiator is less than the above 0.01 part by weight,
If the amount is more than 10 parts by weight, it is not appropriate because the initial hardness and resolution will decrease when the composition is photocured.
When the composition is photocured, the curing time increases and the initial hardness decreases, which is not suitable.

In addition, if the content of the initiator is too large relative to the crosslinking agent, the curing time of the composition will increase.
It is preferably within 0% by weight.

The composition of this invention has much better thermal stability than known unsaturated polyester resin compositions, is stable at temperatures below 100°C, and can be photocured without adding a thermal polymerization stabilizer. At the same time, it is hardly affected by the heat rays in the light beam or the heat generated, and a suitable relief without crosslinking due to heat can be obtained.

However, by adding an appropriate amount of a suitable thermal polymerization stabilizer, the upper limit of the stable temperature can be raised to 150°C.

For example, 0.005 to 1 part by weight of hydroquinone, p-benzoquinone, α-naphthylamine, etc. can be added to 100 parts by weight of modified polybutadiene.

When these thermal polymerization stabilizers are added, the curing time for photocuring the composition becomes longer, so it is better not to add the thermal polymerization stabilizers if possible.

The composition of the present invention is a colorless and transparent liquid substance, and the curing time according to the measuring method used in the examples is within 100 seconds, and by irradiating this composition with light, relief for printing can be made in a short time. can be manufactured.

The manufacturing methods for this relief include iron, stainless steel,
A metal plate such as zinc or aluminum, a rubber sheet made of natural rubber or synthetic rubber, or a resin film made of celluloid, polyester, polyvinyl chloride, polyvinylidene chloride, polyethylene, polypropylene, polyethylene phthalate, etc. is used as a support, and the present invention is applied. The composition is 0.1
Depositing a layer of ~6 mm thickness and then applying to the composition layer,
Light from a light source (such as a chemical lamp, high pressure or low pressure mercury lamp) that mainly emits light with a wavelength of 250 to 350 mμ is irradiated through the negative film, and if the support is a transparent film, if necessary, the support for the cured product is irradiated. In order to improve adhesion, the composition is cured by irradiating the above light from the opposite side for a short time, and the unexposed and uncured parts are dissolved and removed with an aqueous sodium hydroxide solution or a polar solvent and dried. If necessary, there is a method in which the dried cured product is further irradiated with light (post-exposure) to create a relief.

In this case, the exposure time varies depending on the type of each component of the composition, their composition ratio, the thickness of the composition layer, the intensity of the light source, the type of light, the photocuring temperature, etc.

When photocuring a 1 mm thick composition layer with a 20 watt chemical lamp 10 cm apart, the exposure time through the negative film may be about 2 minutes, and the total exposure time including the post-exposure time Within 5 minutes.

Moreover, even without using the resin film support described above,
After irradiating light through the negative film, it is exposed to light from the opposite side for a short time before being dissolved and removed with a basic aqueous solution or polar solvent.
It is also possible to make a relief that is partially cured by irradiation with the above-mentioned light and used as a support.

In addition to the photocuring method described above, the composition of the present invention can be photocured to form a relief using various known methods.

The relief having the unevenness obtained as described above can be directly attached to the plate cylinder of a printing machine as a printing original plate for printing.

The cured product obtained by irradiating the composition of this invention with light has excellent properties such as an initial hardness of 70 or more, a wetness ratio of 3% by weight or less, and a resolution of 6.3 lines/mm or more as measured by the measurement method described below. It also has good swelling resistance to organic solvents such as acetone, benzene, toluene, alcohol, and acetate, and has good affinity with ink and transfers ink to pulp paper, films such as polyethylene, polystyrene, and polypropylene, and synthetic paper. It has excellent properties and is suitable as a relief.

In addition to printing relief, the compositions of this invention can also be used in a wide range of applications such as paints, adhesives, displays, lenses, photoresists, etc.

Examples and comparative examples are shown below.

In the Examples and Comparative Examples, the curing time was determined using a 20 Watt chemical lamp [manufactured by Tokyo Shibaura Electric Co., Ltd., trade name;
FL20BL] was used to irradiate light from a distance of 10 cm from the composition layer to cure the 1 mm thick composition layer until the composition lost its fluidity and no longer adhered to the paper. The time required is shown in seconds (sec).

The initial hardness was determined by measuring a 3 mm thick glass plate placed horizontally (
A polyvinylidene chloride film (manufactured by Asahi Dow Co., Ltd., trade name: Saran Wrap) with a thickness of 10 μm was placed over a glass plate for thin layer chromatography manufactured by Mitamura Riken Kogyo Co., Ltd., and a film with an inner size of 5 cm × 5cmL, height 1mm,
Place a polybutadiene rubber formwork with a frame width of 1 CIrL,
The dish-shaped space formed by the mold and the film is filled with the composition to form a composition layer, and then a 100μ thick polyester film [manufactured by Toshiku Kiki Co., Ltd.] is placed on top of the composition layer.
A glass plate similar to that described above was placed on top of it, and the light from the chemical lamp was applied to the composition layer (25 cm) from below, separated from the composition layer.
℃) for 5 minutes, then 10 CrrL above the composition layer.
The composition layer was cured by irradiating the same light for 1 minute, and only this cured sheet was taken out from the mold, and immediately a test piece of 5 stacked sheets was prepared according to the JISK-6301 Type A spring type hardness test method. The hardness was measured using a hardness measuring device [Jurometer, manufactured by Toyo Seiki Seisakusho], and this hardness was taken as the initial hardness.

The wettability of the cured sheet cured in the same manner as above was 25%.
C. and 100% humidity for 20 hours, and the ratio of the increased mold amount after wetting to the weight of the cured sheet before wetting is shown in %.

The resolving power was determined by placing a negative film of the same size made from a parallel resolution cover turn (Test Chart 41 manufactured by the Electrophotographic Society) on a glass plate similar to the above, and overlaying a polyvinylidene chloride film similar to the above. Inner size is 5cm
A rubber mold with a size of 5 cm x 5 cm, a height of 0.5 mm, and a frame width of 1 cm is placed, the dish-shaped space formed by the mold and the film is filled with the composition, and the same polyester film as above is placed on top of the composition. The light from the chemical lamp (20 watts) 5 cIn below the composition layer (25°C)
The composition layer was cured by irradiating light from the chemical lamp for 20 seconds from 10 CIrL above the composition layer, and the cured sheet of the composition was taken out and the uncured portion was immersed in an aqueous potassium hydroxide solution for several minutes. We cleaned it, made a relief, observed the condition of the relief, and determined the resolution.

Examples 1 to 9 In a 1000 m7 micro flask equipped with a stirring bar and a thermometer, a sample having a microstructure with a 1/2 structure content of 83.5%, a transut 4 structure content of 165%, and a molecular weight of 102
A solution prepared by dissolving 54.1 g of liquid polybutadiene (0) and formic acid in the amount shown in Table 1 in 100 ml of chloroform was added, and while stirring vigorously, a 30% by weight aqueous hydrogen peroxide solution was added in the amount shown in Table 1. In addition, since heat was generated at this time, the mixture was cooled with water and kept at about 40°C, and the reaction was continued with stirring for about 2 hours.

The reaction solution was washed with water, dried over anhydrous sodium sulfate overnight, and chloroform was distilled off under reduced pressure to obtain a modified polybutadiene in which hydroxyl groups and ester groups were bonded in the proportions shown in Table 1.

10 g of the modified polybutadiene obtained as described above, 5 g of triethylene glycol dimethacrylate, and the first
The compositions were made by mixing the amounts of benzoin methyl ether shown in the table.

Table 1 shows the curing time, initial hardness, wettability, and resolution of the photocured product when this composition was photocured.

Note: C4 units refer to butadiene units in modified polybutadiene.

Further, TGDM refers to triethylene glycol dimethacrylate.

In the following examples, C4 unit and TGDM have the same meaning.

Examples 10-14 Liquid polybutadiene similar to Example 6 (1/2 structure 83
．． 5%, trans-1.4 structure 16.5%, molecular weight 10
20) Dissolve 21642 and 228 ml of formic acid in 400 ml of chloroform, and then add hydrogen peroxide aqueous solution (30 ml) to 400 ml of chloroform.
Example 6 except that 80 ml of weight%) was added and reacted.
The reaction was carried out in the same manner as above, and the reaction product was collected.

The obtained product has 0.266/C4 single hydroxyl group and 0
．． 1/C4 unit of formyloxy group (-0-CO-H
) was a modified polybutadiene with

A composition was prepared by mixing 10 g of the modified polybutadiene described above, triethylene glycol dimethacrylate in the amounts shown in Table 2, and 0.27 g of benzoin methyl ether.

Table 2 shows the curing time, initial hardness, wettability, and resolution of the photocured product when this composition was photocured.

Examples 15-21 Compositions were prepared in the same manner as in Example 6, except that 1° of the modified polybutadiene prepared in Example 10 was used and benzoin methyl ether was used in the amount shown in Table 3.

Table 3 shows the curing time, initial hardness, wettability, and resolution of the photocured product when this composition was photocured.

Example 22 A modified polybutadiene was produced in the same manner as in Example 6 except that 120 ml of acetic acid was used instead of formic acid.

This modified polybutadiene has 0.277/C4 single hydroxyl groups and 0.100/C4 single acetyloxy (-0-
It was a modified polyptadiene in which CO-CH3) was bonded.

A composition was prepared in the same manner as in Example 3 except that the above-mentioned modified polybutadiene was used.

The photocuring time for photocuring this composition was 70 seconds, and the photocured product had an initial hardness of 96, a wetness rate of 1.3%, and a resolution of 10.0 lines/h.

Example 23 A modified polybutadiene was produced in the same manner as in Example 6 except that 150 ml of propionic acid was used instead of formic acid.

This modified polybutadiene has 0.25 hydroxyl groups/C4 units and 0.10 propionyloxy groups/C4 units (
-0-CO-CH2-CH3) is bound to modified polybutadiene.

A composition was prepared in the same manner as in Example 3 except that the above-mentioned modified polybutadiene was used.

The photocuring time for photocuring this composition was 90 seconds, the initial hardness of the photocured product was 95, the wettability was 1.4%, and the resolution was 10.0 lines/m.
It was m.

Examples 24 to 27 Modified polybutadiene produced in the same manner as in Example 7 was used, except that the crosslinking agent shown in Table 4 was used instead of the crosslinking agent triethylene glycol dimethacrylate.
A composition was prepared in the same manner as in Example 7.

Table 4 shows the curing time, initial hardness, wettability, and resolution of the photocured product when this composition was photocured.

Examples 22 to 35 54.1 g of liquid polybutadiene having the microstructure and molecular weight shown in Table 5, and formic acid and hydrogen peroxide aqueous solution (30% by weight) in the amounts shown in Table 5 were used.
The reaction was carried out in the same manner as in Example 6, and the reaction product was collected.

Table 5 shows the ratio (number/C4 unit) of hydroxyl groups and formyloxy groups bonded to the obtained modified polybutadiene.

A composition was prepared in the same manner as in Example 3 except that the modified polybutadiene shown in Table 5 above was used.

Table 6 shows the curing time, initial hardness, wettability, and resolution of the photocured product when this composition was photocured.

Comparative example 1 7.68 g of trimellitic anhydride, 157 g of maleic anhydride
2, and 19.0 g of ethylene glycol in a nitrogen gas atmosphere at 100 to 120°C for 30 minutes, then at 170°C.
The mixture was reacted for 4 hours to produce an unsaturated polyester with an acid value of 200.

A composition was produced in the same manner as in Example 1, except that this unsaturated polyester 1M' was used instead of the modified polybutadiene.

The physical properties of this composition were measured when it was photocured.

As a result, the initial hardness was 92, the wettability was 6.8%, and the resolution was 160.

Comparative Example 2 A composition was prepared in the same manner as in Example 1, except that double-terminated carboxyl polybutadiene (manufactured by Nippon Soda, trade name: N15SO-PB, C-1000) was used instead of the modified polybutadiene. This composition was milky white and opaque, and when it was photocured, the initial hardness of the photocured product was 45.

Comparative Example 3 Polybutadiene with hydroxyl groups at both ends [manufactured by Nippon Soda,
A composition was prepared in the same manner as in Example 1, except that N15SO-PB, G-]000) was used in place of the modified polybutadiene, but the properties of this composition were also the same as those in Comparative Example 2. It was almost the same.

Claims (1)

[Scope of Claims] 1 Liquid polybutadiene with a molecular weight of 500 to 5,000 is added with a hydroxyl group and/or with the general formula -0-COR (where R is a hydrogen atom or has 1 to 1 carbon atoms)
100 parts by weight of a modified polybutadiene in which ester groups represented by (5) are bonded in a total amount of 0.2 to 0.6 per butadiene unit of the liquid polybutadiene; As an agent, at least one compound selected from the group consisting of (1) a glycol diester represented by the general formula, (2) a glycidyl ester represented by the general formula, and (3) a trimethylolpropane triester represented by the general formula 20 to 200
parts by weight (in the formula, n is an integer of 1 to 4, and R' and M are hydrogen atoms or methyl groups), and as an initiator, the general formula R'' is an alkyl group having 1 to 3 carbon atoms. ) A photocurable modified polybutadiene composition comprising 0.01 to 10 parts by weight of benzoin ether represented by: